General Information About Colon Cancer

Incidence and Mortality

Estimated new cases and deaths from colon cancer in the United States in 2012:[1]

• New cases: 103,170 (colon cancer only).
• Deaths: 51,690 (colon and rectal cancers combined).

Cancer of the colon is a highly treatable and often curable disease when localized to the bowel. Surgery is the primary form of treatment and results in cure in approximately 50% of the patients. Recurrence following surgery is a major problem and is often the ultimate cause of death.

Prognostic Factors

The prognosis of patients with colon cancer is clearly related to the degree of penetration of the tumor through the bowel wall, the presence or absence of nodal involvement, and the presence or absence of distant metastases. These three characteristics form the basis for all staging systems developed for this disease. Bowel obstruction and bowel perforation are indicators of poor prognosis.[2] Elevated pretreatment serum levels of carcinoembryonic antigen (CEA) have a negative prognostic significance.[3] The American Joint Committee on Cancer and a National Cancer Institute-sponsored panel recommended that at least 12 lymph nodes be examined in patients with colon and rectal cancer to confirm the absence of nodal involvement by tumor.[4,5,6] This recommendation takes into consideration that the number of lymph nodes examined is a reflection of the aggressiveness of lymphovascular mesenteric dissection at the time of surgical resection and the pathologic identification of nodes in the specimen. Retrospective studies demonstrated that the number of lymph nodes examined in colon and rectal surgery may be associated with patient outcome.[7,8,9,10]

Many other prognostic markers have been evaluated retrospectively for patients with colon cancer, though most, including allelic loss of chromosome 18q or thymidylate synthase expression, have not been prospectively validated.[11,12,13,14,15,16,17,18,19,20] Microsatellite instability, also associated with hereditary nonpolyposis colon cancer (HNPCC), has been associated with improved survival independent of tumor stage in a population-based series of 607 patients younger than 50 years with colorectal cancer.[21] Treatment decisions depend on factors such as physician and patient preferences and the stage of the disease rather than the age of the patient.[22,23,24] Racial differences in overall survival after adjuvant therapy have been observed, without differences in disease-free survival, suggesting that comorbid conditions play a role in survival outcome in different patient populations.[25]

Risk Factors

Because of the frequency of the disease, ability to identify high-risk groups, demonstrated slow growth of primary lesions, better survival of patients with early-stage lesions, and relative simplicity and accuracy of screening tests, screening for colon cancer should be a part of routine care for all adults aged 50 years or older, especially for those with first-degree relatives with colorectal cancer. Groups that have a high incidence of colorectal cancer include those with hereditary conditions, such as familial polyposis, HNPCC or Lynch syndrome variants I and II, and those with a personal history of ulcerative colitis or Crohn colitis.[26,27] Together, they account for 10% to 15% of colorectal cancers. Patients with HNPCC reportedly have better prognoses in stage-stratified survival analysis than patients with sporadic colorectal cancer, but the retrospective nature of the studies and possibility of selection factors make this observation difficult to interpret.[28][Level of evidence: 3iiiA] More common conditions with an increased risk include a personal history of colorectal cancer or adenomas; first-degree family history of colorectal cancer or adenomas; and a personal history of ovarian, endometrial, or breast cancer.[29,30] These high-risk groups account for only 23% of all colorectal cancers. Limiting screening or early cancer detection to only these high-risk groups would miss the majority of colorectal cancers.[31] (Refer to the PDQ summaries on Colorectal Cancer Prevention and Colorectal Cancer Screening for more information.)

Follow-up

Following treatment of colon cancer, periodic evaluations may lead to the earlier identification and management of recurrent disease.[32,33,34,35] The impact of such monitoring on overall mortality of patients with recurrent colon cancer, however, is limited by the relatively small proportion of patients in whom localized, potentially curable metastases are found. To date, no large-scale randomized trials have documented the efficacy of a standard, postoperative monitoring program.[36,37,38,39,40] CEA is a serum glycoprotein frequently used in the management of patients with colon cancer. A review of the use of this tumor marker suggests the following:[41]

• A CEA level is not a valuable screening test for colorectal cancer because of the large numbers of false-positive and false-negative reports.
• Postoperative CEA testing should be restricted to patients who would be candidates for resection of liver or lung metastases.
• Routine use of CEA levels alone for monitoring response to treatment should not be recommended.

The optimal regimen and frequency of follow-up examinations are not well defined because the impact on patient survival is not clear, and the quality of data is poor.[38,39,40] New surveillance methods, including CEA immunoscintigraphy [42] and positron emission tomography,[43] are under clinical evaluation.

Gastrointestinal stromal tumors can occur in the colon. (Refer to the PDQ summary on Gastrointestinal Stromal Tumors Treatment for more information.)

Related Summaries

Other PDQ summaries containing information related to colon cancer include the following:

• Colorectal Cancer Prevention
• Colorectal Cancer Screening
• Genetics of Colorectal Cancer
• Unusual Cancers of Childhood Treatment (childhood cancer of the colon)

References:

1.	American Cancer Society.: Cancer Facts and Figures 2012. Atlanta, Ga: American Cancer Society, 2012. Available online. Last accessed June 14, 2012.
2.	Steinberg SM, Barkin JS, Kaplan RS, et al.: Prognostic indicators of colon tumors. The Gastrointestinal Tumor Study Group experience. Cancer 57 (9): 1866-70, 1986.
3.	Filella X, Molina R, Grau JJ, et al.: Prognostic value of CA 19.9 levels in colorectal cancer. Ann Surg 216 (1): 55-9, 1992.
4.	Colon and rectum. In: American Joint Committee on Cancer.: AJCC Cancer Staging Manual. 6th ed. New York, NY: Springer, 2002, pp 113-124.
5.	Compton CC, Greene FL: The staging of colorectal cancer: 2004 and beyond. CA Cancer J Clin 54 (6): 295-308, 2004 Nov-Dec.
6.	Nelson H, Petrelli N, Carlin A, et al.: Guidelines 2000 for colon and rectal cancer surgery. J Natl Cancer Inst 93 (8): 583-96, 2001.
7.	Swanson RS, Compton CC, Stewart AK, et al.: The prognosis of T3N0 colon cancer is dependent on the number of lymph nodes examined. Ann Surg Oncol 10 (1): 65-71, 2003 Jan-Feb.
8.	Le Voyer TE, Sigurdson ER, Hanlon AL, et al.: Colon cancer survival is associated with increasing number of lymph nodes analyzed: a secondary survey of intergroup trial INT-0089. J Clin Oncol 21 (15): 2912-9, 2003.
9.	Prandi M, Lionetto R, Bini A, et al.: Prognostic evaluation of stage B colon cancer patients is improved by an adequate lymphadenectomy: results of a secondary analysis of a large scale adjuvant trial. Ann Surg 235 (4): 458-63, 2002.
10.	Tepper JE, O'Connell MJ, Niedzwiecki D, et al.: Impact of number of nodes retrieved on outcome in patients with rectal cancer. J Clin Oncol 19 (1): 157-63, 2001.
11.	McLeod HL, Murray GI: Tumour markers of prognosis in colorectal cancer. Br J Cancer 79 (2): 191-203, 1999.
12.	Jen J, Kim H, Piantadosi S, et al.: Allelic loss of chromosome 18q and prognosis in colorectal cancer. N Engl J Med 331 (4): 213-21, 1994.
13.	Lanza G, Matteuzzi M, Gafá R, et al.: Chromosome 18q allelic loss and prognosis in stage II and III colon cancer. Int J Cancer 79 (4): 390-5, 1998.
14.	Griffin MR, Bergstralh EJ, Coffey RJ, et al.: Predictors of survival after curative resection of carcinoma of the colon and rectum. Cancer 60 (9): 2318-24, 1987.
15.	Johnston PG, Fisher ER, Rockette HE, et al.: The role of thymidylate synthase expression in prognosis and outcome of adjuvant chemotherapy in patients with rectal cancer. J Clin Oncol 12 (12): 2640-7, 1994.
16.	Shibata D, Reale MA, Lavin P, et al.: The DCC protein and prognosis in colorectal cancer. N Engl J Med 335 (23): 1727-32, 1996.
17.	Bauer KD, Lincoln ST, Vera-Roman JM, et al.: Prognostic implications of proliferative activity and DNA aneuploidy in colonic adenocarcinomas. Lab Invest 57 (3): 329-35, 1987.
18.	Bauer KD, Bagwell CB, Giaretti W, et al.: Consensus review of the clinical utility of DNA flow cytometry in colorectal cancer. Cytometry 14 (5): 486-91, 1993.
19.	Sun XF, Carstensen JM, Zhang H, et al.: Prognostic significance of cytoplasmic p53 oncoprotein in colorectal adenocarcinoma. Lancet 340 (8832): 1369-73, 1992.
20.	Roth JA: p53 prognostication: paradigm or paradox? Clin Cancer Res 5 (11): 3345, 1999.
21.	Gryfe R, Kim H, Hsieh ET, et al.: Tumor microsatellite instability and clinical outcome in young patients with colorectal cancer. N Engl J Med 342 (2): 69-77, 2000.
22.	Iwashyna TJ, Lamont EB: Effectiveness of adjuvant fluorouracil in clinical practice: a population-based cohort study of elderly patients with stage III colon cancer. J Clin Oncol 20 (19): 3992-8, 2002.
23.	Chiara S, Nobile MT, Vincenti M, et al.: Advanced colorectal cancer in the elderly: results of consecutive trials with 5-fluorouracil-based chemotherapy. Cancer Chemother Pharmacol 42 (4): 336-40, 1998.
24.	Popescu RA, Norman A, Ross PJ, et al.: Adjuvant or palliative chemotherapy for colorectal cancer in patients 70 years or older. J Clin Oncol 17 (8): 2412-8, 1999.
25.	Dignam JJ, Colangelo L, Tian W, et al.: Outcomes among African-Americans and Caucasians in colon cancer adjuvant therapy trials: findings from the National Surgical Adjuvant Breast and Bowel Project. J Natl Cancer Inst 91 (22): 1933-40, 1999.
26.	Thorson AG, Knezetic JA, Lynch HT: A century of progress in hereditary nonpolyposis colorectal cancer (Lynch syndrome). Dis Colon Rectum 42 (1): 1-9, 1999.
27.	Smith RA, von Eschenbach AC, Wender R, et al.: American Cancer Society guidelines for the early detection of cancer: update of early detection guidelines for prostate, colorectal, and endometrial cancers. Also: update 2001--testing for early lung cancer detection. CA Cancer J Clin 51 (1): 38-75; quiz 77-80, 2001 Jan-Feb.
28.	Watson P, Lin KM, Rodriguez-Bigas MA, et al.: Colorectal carcinoma survival among hereditary nonpolyposis colorectal carcinoma family members. Cancer 83 (2): 259-66, 1998.
29.	Ransohoff DF, Lang CA: Screening for colorectal cancer. N Engl J Med 325 (1): 37-41, 1991.
30.	Fuchs CS, Giovannucci EL, Colditz GA, et al.: A prospective study of family history and the risk of colorectal cancer. N Engl J Med 331 (25): 1669-74, 1994.
31.	Winawer SJ: Screening for colorectal cancer. Cancer: Principles and Practice of Oncology Updates 2(1): 1-16, 1987.
32.	Martin EW Jr, Minton JP, Carey LC: CEA-directed second-look surgery in the asymptomatic patient after primary resection of colorectal carcinoma. Ann Surg 202 (3): 310-7, 1985.
33.	Bruinvels DJ, Stiggelbout AM, Kievit J, et al.: Follow-up of patients with colorectal cancer. A meta-analysis. Ann Surg 219 (2): 174-82, 1994.
34.	Lautenbach E, Forde KA, Neugut AI: Benefits of colonoscopic surveillance after curative resection of colorectal cancer. Ann Surg 220 (2): 206-11, 1994.
35.	Khoury DA, Opelka FG, Beck DE, et al.: Colon surveillance after colorectal cancer surgery. Dis Colon Rectum 39 (3): 252-6, 1996.
36.	Safi F, Link KH, Beger HG: Is follow-up of colorectal cancer patients worthwhile? Dis Colon Rectum 36 (7): 636-43; discussion 643-4, 1993.
37.	Moertel CG, Fleming TR, Macdonald JS, et al.: An evaluation of the carcinoembryonic antigen (CEA) test for monitoring patients with resected colon cancer. JAMA 270 (8): 943-7, 1993.
38.	Rosen M, Chan L, Beart RW Jr, et al.: Follow-up of colorectal cancer: a meta-analysis. Dis Colon Rectum 41 (9): 1116-26, 1998.
39.	Desch CE, Benson AB 3rd, Smith TJ, et al.: Recommended colorectal cancer surveillance guidelines by the American Society of Clinical Oncology. J Clin Oncol 17 (4): 1312, 1999.
40.	Benson AB 3rd, Desch CE, Flynn PJ, et al.: 2000 update of American Society of Clinical Oncology colorectal cancer surveillance guidelines. J Clin Oncol 18 (20): 3586-8, 2000.
41.	Clinical practice guidelines for the use of tumor markers in breast and colorectal cancer. Adopted on May 17, 1996 by the American Society of Clinical Oncology. J Clin Oncol 14 (10): 2843-77, 1996.
42.	Lechner P, Lind P, Goldenberg DM: Can postoperative surveillance with serial CEA immunoscintigraphy detect resectable rectal cancer recurrence and potentially improve tumor-free survival? J Am Coll Surg 191 (5): 511-8, 2000.
43.	Lonneux M, Reffad AM, Detry R, et al.: FDG-PET improves the staging and selection of patients with recurrent colorectal cancer. Eur J Nucl Med Mol Imaging 29 (7): 915-21, 2002.

Cellular Classification of Colon Cancer

Histologic types of colon cancer include the following:

• Adenocarcinoma (most colon cancers).
  • Mucinous (colloid) adenocarcinoma.
  • Signet ring adenocarcinoma.
• Scirrhous tumors.
• Neuroendocrine.[1] Tumors with neuroendocrine differentiation typically have a poorer prognosis than pure adenocarcinoma variants.

References:

1.	Saclarides TJ, Szeluga D, Staren ED: Neuroendocrine cancers of the colon and rectum. Results of a ten-year experience. Dis Colon Rectum 37 (7): 635-42, 1994.

Stage Information for Colon Cancer

Treatment decisions should be made with reference to the TNM classification [1] rather than to the older Dukes or the Modified Astler-Coller classification schema.

The American Joint Committee on Cancer (AJCC) and a National Cancer Institute-sponsored panel recommended that at least 12 lymph nodes be examined in patients with colon and rectal cancer to confirm the absence of nodal involvement by tumor.[2,3,4] This recommendation takes into consideration that the number of lymph nodes examined is a reflection of the aggressiveness of lymphovascular mesenteric dissection at the time of surgical resection and the pathologic identification of nodes in the specimen. Retrospective studies demonstrated that the number of lymph nodes examined in colon and rectal surgery may be associated with patient outcome.[5,6,7,8]

Definitions of TNM

The AJCC has designated staging by TNM classification to define colon cancer.[1] The same classification is used for both clinical and pathologic staging.[1]

Table 1. Primary Tumor^a

a Reprinted with permission from AJCC: Colon and rectum. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 143-164.
b Tis includes cancer cells confined within the glandular basement membrane (intraepithelial) or mucosal lamina propria (intramucosal) with no extension through the muscularis mucosae into the submucosa.
c Direct invasion in T4 includes invasion of other organs or other segments of the colorectum as a result of direct extension through the serosa, as confirmed on microscopic examination (e.g., invasion of the sigmoid colon by a carcinoma of the cecum) or, for cancers in a retroperitoneal or subperitoneal location, direct invasion of other organs or structures by virtue of extension beyond the muscularis propria (i.e., respectively, a tumor on the posterior wall of the descending colon invading the left kidney or lateral abdominal wall; or a mid or distal rectal cancer with invasion of prostate, seminal vesicles, cervix, or vagina).
d Tumor that is adherent to other organs or structures, grossly, is classified cT4b. However, if no tumor is present in the adhesion, microscopically, the classification should be pT1–4a depending on the anatomical depth of wall invasion. The V and L classifications should be used to identify the presence or absence of vascular or lymphatic invasion whereas the PN site-specific factor should be used for perineural invasion.
TX	Primary tumor cannot be assessed.
T0	No evidence of primary tumor.
Tis	Carcinomain situ: intraepithelial or invasion of lamina propria.b
T1	Tumor invades submucosa.
T2	Tumor invades muscularis propria.
T3	Tumor invades through the muscularis propria into pericolorectal tissues.
T4a	Tumor penetrates to the surface of the visceral peritoneum.c
T4b	Tumor directly invades or is adherent to other organs or structures.c,d

Table 2. Regional Lymph Nodes (N)^a,b

a Reprinted with permission from AJCC: Colon and rectum. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 143-164.
b A satellite peritumoral nodule in the pericolorectal adipose tissue of a primary carcinoma without histologic evidence of residual lymph node in the nodule may represent discontinuous spread, venous invasion with extravascular spread (V1/2), or a totally replaced lymph node (N1/2). Replaced nodes should be counted separately as positive nodes in the N category, whereas discontinuous spread or venous invasion should be classified and counted in the site-specific factor category Tumor Deposits.
NX	Regional lymph nodes cannot be assessed.
N0	No regional lymph node metastasis.
N1	Metastases in 1–3 regional lymph nodes.
N1a	Metastasis in 1 regional lymph node.
N1b	Metastases in 2–3 regional lymph nodes.
N1c	Tumor deposit(s) in the subserosa, mesentery, or nonperitonealized pericolic or perirectal tissues without regional nodal metastasis.
N2	Metastases in ≥4 regional lymph nodes.
N2a	Metastases in 4–6 regional lymph nodes.
N2b	Metastases in ≥7 regional lymph nodes.

Table 3. Distant Metastasis (M)^a

a Reprinted with permission from AJCC: Colon and rectum. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 143-164.
M0	No distant metastasis.
M1	Distant metastasis.
M1a	Metastasis confined to 1 organ or site (e.g., liver, lung, ovary, nonregional node).
M1b	Metastases in >1 organ/site or the peritoneum.

Table 4. Anatomic Stage/Prognostic Groups^a,b

Stage	T	N	M	Dukesc	MACc
a Reprinted with permission from AJCC: Colon and rectum. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 143-164.
b cTNM is the clinical classification, and pTNM is the pathologic classification. The y prefix is used for those cancers that are classified after neoadjuvant pretreatment (e.g., ypTNM). Patients who have a complete pathologic response (ypT0, N0, cM0) may be similar to stage group 0 or I. The r prefix is to be used for those cancers that have recurred after a disease-free interval (rTNM).
c Dukes B is a composite of better (T3, N0, M0) and worse (T4, N0, M0) prognostic groups, as is Dukes C (any T, N1, M0 and any T, N2, M0). MAC is the modified Astler-Coller classification.
0	Tis	N0	M0	–	–
I	T1	N0	M0	A	A
	T2	N0	M0	A	B1
IIA	T3	N0	M0	B	B2
IIB	T4a	N0	M0	B	B2
IIC	T4b	N0	M0	B	B3
IIIA	T1–T2	N1/N1c	M0	C	C1
	T1	N2a	M0	C	C1
IIIB	T3–T4a	N1/N1c	M0	C	C2
	T2–T3	N2a	M0	C	C1/C2
	T1–T2	N2b	M0	C	C1
IIIC	T4a	N2a	M0	C	C2
	T3–T4a	N2b	M0	C	C2
	T4b	N1–N2	M0	C	C3
IVA	Any T	Any N	M1a	–	–
IVB	Any T	Any N	M1b	–	–

References:

1.	Colon and rectum. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 143-64.
2.	Colon and rectum. In: American Joint Committee on Cancer.: AJCC Cancer Staging Manual. 6th ed. New York, NY: Springer, 2002, pp 113-124.
3.	Compton CC, Greene FL: The staging of colorectal cancer: 2004 and beyond. CA Cancer J Clin 54 (6): 295-308, 2004 Nov-Dec.
4.	Nelson H, Petrelli N, Carlin A, et al.: Guidelines 2000 for colon and rectal cancer surgery. J Natl Cancer Inst 93 (8): 583-96, 2001.
5.	Swanson RS, Compton CC, Stewart AK, et al.: The prognosis of T3N0 colon cancer is dependent on the number of lymph nodes examined. Ann Surg Oncol 10 (1): 65-71, 2003 Jan-Feb.
6.	Le Voyer TE, Sigurdson ER, Hanlon AL, et al.: Colon cancer survival is associated with increasing number of lymph nodes analyzed: a secondary survey of intergroup trial INT-0089. J Clin Oncol 21 (15): 2912-9, 2003.
7.	Prandi M, Lionetto R, Bini A, et al.: Prognostic evaluation of stage B colon cancer patients is improved by an adequate lymphadenectomy: results of a secondary analysis of a large scale adjuvant trial. Ann Surg 235 (4): 458-63, 2002.
8.	Tepper JE, O'Connell MJ, Niedzwiecki D, et al.: Impact of number of nodes retrieved on outcome in patients with rectal cancer. J Clin Oncol 19 (1): 157-63, 2001.

Treatment Option Overview

Primary Surgical Therapy

Standard treatment for patients with colon cancer has been open surgical resection of the primary and regional lymph nodes for localized disease. The role of laparoscopic techniques [1,2,3,4] in the treatment of colon cancer has been examined in two studies. A multicenter, prospective, randomized, noninferiority trial (NCCTG-934653) compared laparoscopic-assisted colectomy (LAC) to open colectomy in 872 patients. At a median follow-up of 4.4 years, 3-year recurrence rates (16% LAC vs. 18% open colectomy; hazard ratio [HR] for recurrence, 0.86; 95% confidence interval [CI], 0.63–1.17; P = .32) and 3-year overall survival (OS) rates (86% LAC vs. 85% open colectomy; HR for death in LAC, 0.91; 95% CI, 0.68–1.21; P = .51) were similar in both groups for all stages of disease evaluated.[5][Level of evidence: 1iiA]. Tumor recurrence in surgical incisions was less than 1% for both groups. Decreased hospital stay (5 days LAC vs. 6 days open colectomy, P < .001) and decreased use of analgesics were reported in the LAC group. A 21% conversion rate from LAC to open procedure was shown. This study excluded patients with locally advanced disease, transverse colon and rectal tumor locations, and perforated lesions. Each of the 66 surgeons participating in the trial had performed at least 20 LACs and were accredited for study participation after independent videotape review assured appropriate oncologic and surgical principles were maintained.[5] The quality-of-life component of this trial was published separately and minimal short-term quality-of-life benefits with LAC were reported.[6][Level of evidence: 1iiC] One small, single-institution randomized study of 219 patients showed that the LAC procedure was independently associated with reduced tumor recurrence on multivariate analysis.[7][Level of evidence: 1iiB] The role of sentinel lymph node mapping is also under clinical evaluation.[8,9]

Surgery is curative in 25% to 40% of highly selected patients who develop resectable metastases in the liver and lung. Improved surgical techniques and advances in preoperative imaging have allowed for better patient selection for resection.

Adjuvant Chemotherapy

The potential value of adjuvant chemotherapy for patients with stage II colon cancer is controversial. Pooled analyses and meta-analyses have suggested a 2% to 4% improvement in OS for patients treated with adjuvant fluorouracil (5-FU)–based therapy compared with observation.[10,11,12] (Refer to the section of this summary on Stage II Colon Cancer for more information.)

Prior to 2000, 5-FU was the only useful cytotoxic chemotherapy in the adjuvant setting for patients with stage III colon cancer. Since 2000, capecitabine has been established as an equivalent alternative to 5-FU and leucovorin. The addition of oxaliplatin to 5-FU and leucovorin has been shown to improve OS compared with 5-FU and leucovorin alone. (Refer to the sections of this summary on Stage III Colon Cancer and Stage IV and Recurrent Colon Cancer for more information.)

Adjuvant Radiation Therapy

While combined modality therapy with chemotherapy and radiation therapy has a significant role in the management of patients with rectal cancer (below the peritoneal reflection), the role of adjuvant radiation therapy for patients with colon cancer (above the peritoneal reflection) is not well defined. Patterns-of-care analyses and single-institution retrospective reviews suggest a role for radiation therapy in certain high-risk subsets of colon cancer patients (T4, tumor location in immobile sites, local perforation, obstruction, and residual disease postresection).[13,14,15,16,17,18] Such observations led to the development of a phase III randomized intergroup study designed to test the benefit of adding radiation therapy to surgery and chemotherapy with 5-FU-levamisole for selected high-risk colon cancer patients (T4; or T3, N1–N2 ascending and/or descending colon).[19] This clinical trial closed early secondary to inadequate patient accrual, and analysis of 222 enrolled patients (the original goal was 700 patients) demonstrated no relapse or OS benefit for the group receiving radiation therapy, though the sample size and statistical power were inadequate to exclude benefit. Adjuvant radiation therapy has no current standard role in the management of patients with colon cancer following curative resection, though it may have a role for patients with residual disease.

References:

1.	Bokey EL, Moore JW, Chapuis PH, et al.: Morbidity and mortality following laparoscopic-assisted right hemicolectomy for cancer. Dis Colon Rectum 39 (10 Suppl): S24-8, 1996.
2.	Franklin ME Jr, Rosenthal D, Abrego-Medina D, et al.: Prospective comparison of open vs. laparoscopic colon surgery for carcinoma. Five-year results. Dis Colon Rectum 39 (10 Suppl): S35-46, 1996.
3.	Fleshman JW, Nelson H, Peters WR, et al.: Early results of laparoscopic surgery for colorectal cancer. Retrospective analysis of 372 patients treated by Clinical Outcomes of Surgical Therapy (COST) Study Group. Dis Colon Rectum 39 (10 Suppl): S53-8, 1996.
4.	Schwenk W, Böhm B, Müller JM: Postoperative pain and fatigue after laparoscopic or conventional colorectal resections. A prospective randomized trial. Surg Endosc 12 (9): 1131-6, 1998.
5.	Clinical Outcomes of Surgical Therapy Study Group.: A comparison of laparoscopically assisted and open colectomy for colon cancer. N Engl J Med 350 (20): 2050-9, 2004.
6.	Weeks JC, Nelson H, Gelber S, et al.: Short-term quality-of-life outcomes following laparoscopic-assisted colectomy vs open colectomy for colon cancer: a randomized trial. JAMA 287 (3): 321-8, 2002.
7.	Lacy AM, García-Valdecasas JC, Delgado S, et al.: Laparoscopy-assisted colectomy versus open colectomy for treatment of non-metastatic colon cancer: a randomised trial. Lancet 359 (9325): 2224-9, 2002.
8.	Esser S, Reilly WT, Riley LB, et al.: The role of sentinel lymph node mapping in staging of colon and rectal cancer. Dis Colon Rectum 44 (6): 850-4; discussion 854-6, 2001.
9.	Bilchik AJ, Nora DT, Sobin LH, et al.: Effect of lymphatic mapping on the new tumor-node-metastasis classification for colorectal cancer. J Clin Oncol 21 (4): 668-72, 2003.
10.	Efficacy of adjuvant fluorouracil and folinic acid in B2 colon cancer. International Multicentre Pooled Analysis of B2 Colon Cancer Trials (IMPACT B2) Investigators. J Clin Oncol 17 (5): 1356-63, 1999.
11.	Gill S, Loprinzi CL, Sargent DJ, et al.: Pooled analysis of fluorouracil-based adjuvant therapy for stage II and III colon cancer: who benefits and by how much? J Clin Oncol 22 (10): 1797-806, 2004.
12.	Mamounas E, Wieand S, Wolmark N, et al.: Comparative efficacy of adjuvant chemotherapy in patients with Dukes' B versus Dukes' C colon cancer: results from four National Surgical Adjuvant Breast and Bowel Project adjuvant studies (C-01, C-02, C-03, and C-04) J Clin Oncol 17 (5): 1349-55, 1999.
13.	Willett C, Tepper JE, Cohen A, et al.: Local failure following curative resection of colonic adenocarcinoma. Int J Radiat Oncol Biol Phys 10 (5): 645-51, 1984.
14.	Willett C, Tepper JE, Cohen A, et al.: Obstructive and perforative colonic carcinoma: patterns of failure. J Clin Oncol 3 (3): 379-84, 1985.
15.	Gunderson LL, Sosin H, Levitt S: Extrapelvic colon--areas of failure in a reoperation series: implications for adjuvant therapy. Int J Radiat Oncol Biol Phys 11 (4): 731-41, 1985.
16.	Willett CG, Fung CY, Kaufman DS, et al.: Postoperative radiation therapy for high-risk colon carcinoma. J Clin Oncol 11 (6): 1112-7, 1993.
17.	Willett CG, Goldberg S, Shellito PC, et al.: Does postoperative irradiation play a role in the adjuvant therapy of stage T4 colon cancer? Cancer J Sci Am 5 (4): 242-7, 1999 Jul-Aug.
18.	Schild SE, Gunderson LL, Haddock MG, et al.: The treatment of locally advanced colon cancer. Int J Radiat Oncol Biol Phys 37 (1): 51-8, 1997.
19.	Martenson JA Jr, Willett CG, Sargent DJ, et al.: Phase III study of adjuvant chemotherapy and radiation therapy compared with chemotherapy alone in the surgical adjuvant treatment of colon cancer: results of intergroup protocol 0130. J Clin Oncol 22 (16): 3277-83, 2004.

Stage 0 Colon Cancer

Stage 0 colon cancer is the most superficial of all the lesions and is limited to the mucosa without invasion of the lamina propria. Because of its superficial nature, the surgical procedure may be limited.

Treatment options:

1.	Local excision or simple polypectomy with clear margins.
2.	Colon resection for larger lesions not amenable to local excision.

Current Clinical Trials

Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with stage 0 colon cancer. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site.

Stage I Colon Cancer

Because of its localized nature, stage I colon cancer has a high cure rate.

Treatment options:

• Wide surgical resection and anastomosis. The role of laparoscopic techniques [1,2,3,4] in the treatment of colon cancer is under evaluation in a multicenter prospective randomized trial (NCCTG-934653) comparing laparoscopic-assisted colectomy (LAC) with open colectomy. The quality-of-life component of this trial has been published and minimal short-term quality-of-life benefits with LAC were reported.[5][Level of evidence: 1iiC]

Current Clinical Trials

Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with stage I colon cancer. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site.

References:

1.	Bokey EL, Moore JW, Chapuis PH, et al.: Morbidity and mortality following laparoscopic-assisted right hemicolectomy for cancer. Dis Colon Rectum 39 (10 Suppl): S24-8, 1996.
2.	Franklin ME Jr, Rosenthal D, Abrego-Medina D, et al.: Prospective comparison of open vs. laparoscopic colon surgery for carcinoma. Five-year results. Dis Colon Rectum 39 (10 Suppl): S35-46, 1996.
3.	Fleshman JW, Nelson H, Peters WR, et al.: Early results of laparoscopic surgery for colorectal cancer. Retrospective analysis of 372 patients treated by Clinical Outcomes of Surgical Therapy (COST) Study Group. Dis Colon Rectum 39 (10 Suppl): S53-8, 1996.
4.	Schwenk W, Böhm B, Müller JM: Postoperative pain and fatigue after laparoscopic or conventional colorectal resections. A prospective randomized trial. Surg Endosc 12 (9): 1131-6, 1998.
5.	Weeks JC, Nelson H, Gelber S, et al.: Short-term quality-of-life outcomes following laparoscopic-assisted colectomy vs open colectomy for colon cancer: a randomized trial. JAMA 287 (3): 321-8, 2002.

Stage II Colon Cancer

Treatment options:

1.

Wide surgical resection and anastomosis. The role of laparoscopic techniques [1,2,3,4] in the treatment of colon cancer was examined in a multicenter prospective randomized trial (NCCTG-934653, now closed) comparing laparoscopic-assisted colectomy (LAC) to open colectomy. The quality-of-life component of this trial has been published and minimal short-term quality-of-life benefits with LAC were reported.[4][Level of evidence: 1iiC]

2.

Following surgery, patients should be considered for entry into a carefully controlled clinical trial. The GRECCR-03 and NCRI-QUASAR1 trials evaluated the use of systemic or regional chemotherapy or biologic therapy. Adjuvant therapy is not indicated for most patients unless they are entered into a clinical trial.

Adjuvant Chemotherapy

The potential value of adjuvant chemotherapy for patients with stage II colon cancer remains controversial. Although subgroups of patients with stage II colon cancer may be at higher-than-average risk for recurrence (including those with anatomic features such as tumor adherence to adjacent structures, perforation, complete obstruction, or with biologic characteristics such as aneuploidy, high S-phase analysis, or deletion of 18q),[5,6,7] evidence is inconsistent that adjuvant 5-fluorouracil (5-FU)–based chemotherapy is associated with an improved overall survival (OS) compared to surgery alone.[8] Investigators from the National Surgical Adjuvant Breast and Bowel Project (NSABP) have indicated that the reduction in risk of recurrence by adjuvant therapy in patients with stage II disease is of similar magnitude to the benefit seen in patients with stage III disease treated with adjuvant therapy, though an OS advantage has not been established.[9]

A meta-analysis of 1,000 stage II patients whose experience was amalgamated from a series of trials indicates a 2% advantage in disease-free survival (DFS) at 5 years when adjuvant therapy-treated patients treated with 5-FU-leucovorin are compared with untreated controls.[10][Level of evidence: 1iiDii[11]

Recently, the Cancer Care Ontario Practice Guideline Initiative Gastrointestinal Cancer Disease Site Group undertook a meta-analysis of the English language published literature consisting of randomized trials where adjuvant chemotherapy was compared with observation for patients with stage II colon cancer. The mortality risk ratio was 0.87 (95% CI, 0.75–1.01; P = .07).[12] Based on these data, the American Society of Clinical Oncology issued a guideline stating "direct evidence from randomized controlled trials does not support the routine use of adjuvant chemotherapy for patients with stage II colon cancer."[13]

Features in patients with stage II colon cancer that are associated with an increased risk of recurrence include inadequate lymph node sampling, T4 disease, involvement of the visceral peritoneum, and a poorly differentiated histology. The decision to use adjuvant chemotherapy for patients with stage II colon cancer is complicated and requires thoughtful consideration for both patients and their physicians.

Current Clinical Trials

Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with stage II colon cancer. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site.

References:

1.	Bokey EL, Moore JW, Chapuis PH, et al.: Morbidity and mortality following laparoscopic-assisted right hemicolectomy for cancer. Dis Colon Rectum 39 (10 Suppl): S24-8, 1996.
2.	Franklin ME Jr, Rosenthal D, Abrego-Medina D, et al.: Prospective comparison of open vs. laparoscopic colon surgery for carcinoma. Five-year results. Dis Colon Rectum 39 (10 Suppl): S35-46, 1996.
3.	Fleshman JW, Nelson H, Peters WR, et al.: Early results of laparoscopic surgery for colorectal cancer. Retrospective analysis of 372 patients treated by Clinical Outcomes of Surgical Therapy (COST) Study Group. Dis Colon Rectum 39 (10 Suppl): S53-8, 1996.
4.	Weeks JC, Nelson H, Gelber S, et al.: Short-term quality-of-life outcomes following laparoscopic-assisted colectomy vs open colectomy for colon cancer: a randomized trial. JAMA 287 (3): 321-8, 2002.
5.	Lanza G, Matteuzzi M, Gafá R, et al.: Chromosome 18q allelic loss and prognosis in stage II and III colon cancer. Int J Cancer 79 (4): 390-5, 1998.
6.	Jen J, Kim H, Piantadosi S, et al.: Allelic loss of chromosome 18q and prognosis in colorectal cancer. N Engl J Med 331 (4): 213-21, 1994.
7.	Merkel S, Wein A, Günther K, et al.: High-risk groups of patients with Stage II colon carcinoma. Cancer 92 (6): 1435-43, 2001.
8.	Moertel CG, Fleming TR, Macdonald JS, et al.: Intergroup study of fluorouracil plus levamisole as adjuvant therapy for stage II/Dukes' B2 colon cancer. J Clin Oncol 13 (12): 2936-43, 1995.
9.	Mamounas E, Wieand S, Wolmark N, et al.: Comparative efficacy of adjuvant chemotherapy in patients with Dukes' B versus Dukes' C colon cancer: results from four National Surgical Adjuvant Breast and Bowel Project adjuvant studies (C-01, C-02, C-03, and C-04) J Clin Oncol 17 (5): 1349-55, 1999.
10.	Efficacy of adjuvant fluorouracil and folinic acid in B2 colon cancer. International Multicentre Pooled Analysis of B2 Colon Cancer Trials (IMPACT B2) Investigators. J Clin Oncol 17 (5): 1356-63, 1999.
11.	Harrington DP: The tea leaves of small trials. J Clin Oncol 17 (5): 1336-8, 1999.
12.	Figueredo A, Charette ML, Maroun J, et al.: Adjuvant therapy for stage II colon cancer: a systematic review from the Cancer Care Ontario Program in evidence-based care's gastrointestinal cancer disease site group. J Clin Oncol 22 (16): 3395-407, 2004.
13.	Benson AB 3rd, Schrag D, Somerfield MR, et al.: American Society of Clinical Oncology recommendations on adjuvant chemotherapy for stage II colon cancer. J Clin Oncol 22 (16): 3408-19, 2004.

Stage III Colon Cancer

Stage III colon cancer denotes lymph node involvement. Studies have indicated that the number of lymph nodes involved affects prognosis; patients with one to three involved nodes have a significantly better survival than those with four or more involved nodes.

Drug combinations described in this section include the following:

• The FOLFOX4 regimen (oxaliplatin, leucovorin, and fluorouracil [5-FU]):
  • Oxaliplatin (85 mg/m²) administered as a 2-hour infusion on day 1; leucovorin (200 mg/m²) administered as a 2-hour infusion on day 1 and day 2; followed by a loading dose of 5-FU (400 mg/m²) IV bolus, then 5-FU (600 mg/m²) administered via ambulatory pump for a period of 22 hours on day 1 and day 2 every 2 weeks.
• The Levamisole regimen (5-FU and levamisole):
  • Bolus 5-FU (450 mg/m² per day) on days 1 to 5, then weekly 28 days later plus levamisole (50 mg) administered orally 3 times a day for 3 days every 2 weeks.
• The Mayo Clinic or NCCTG regimen (5-FU and low-dose leucovorin):
  • Bolus 5-FU-(450 mg/m²)-leucovorin (20 mg/m²) administered daily for 5 days every 28 days.
• The Roswell Park or NSABP regimen (5-FU and high-dose leucovorin):
  • Bolus 5-FU-(500 mg/m²)-leucovorin (500 mg/m²) administered weekly for 6 consecutive weeks every 8 weeks.

Treatment options include the following:

1.

Wide surgical resection and anastomosis. The role of laparoscopic techniques [1,2,3,4] in the treatment of colon cancer was examined in a multicenter prospective randomized trial (NCCTG-934653, now closed) comparing laparoscopic-assisted colectomy (LAC) with open colectomy. The quality-of-life component of this trial has been published and reported minimal short-term quality-of-life benefits with LAC.[5][Level of evidence: 1iiC] Based on results from the MOSAIC (NCT00275210) trial, adjuvant FOLFOX4 demonstrated prolonged overall survival (OS) for patients with stage III colon cancer compared with patients receiving 5-FU/leucovorin without oxaliplatin. The 6-year OS of patients with stage III colon cancer was 72.9% in the patients receiving FOLFOX and 68.9% in the patients receiving 5-FU/LV (hazard ratio [HR], 0.80; 95% confidence interval [CI], 0.65–0.97, P = .023).[6]

2.

Eligible patients should be considered for entry into carefully controlled clinical trials comparing various postoperative chemotherapy regimens.[7]

Adjuvant Chemotherapy

Chemotherapy regimens prior to 2000

Prior to 2000, 5-FU was the only useful cytotoxic chemotherapy in the adjuvant setting for patients with stage III colon cancer. Many of the early randomized studies of 5-FU in the adjuvant setting failed to show a significant improvement in survival for patients.[8,9,10,11] These trials employed 5-FU alone or 5-FU-semustine (methyl-CCNU). The North Central Cancer Treatment Group (NCCTG) conducted a randomized trial comparing surgical resection alone with postoperative levamisole or 5-FU-levamisole.[12][Level of evidence: 1iiA] A significant improvement in disease-free survival (DFS) was observed for patients with stage III colon cancer who received 5-FU-levamisole, but OS benefits were of borderline statistical significance. An absolute survival benefit of approximately 12% (49% vs. 37%) was seen in patients with stage III disease treated with 5-FU-levamisole.

In a large, confirmatory intergroup trial, 5-FU-levamisole prolonged DFS and OS in patients with stage III colon cancer compared with patients who received no treatment after surgery.[13][Level of evidence: 1iiA] Levamisole alone did not confer these benefits. Subsequent studies tested the combination of 5-FU-leucovorin in the adjuvant treatment of patients with resected carcinoma of the colon. Results of multiple randomized trials that have enrolled more than 4,000 patients comparing adjuvant chemotherapy with 5-FU-leucovorin to surgery or 5-FU-semustine-vincristine demonstrate a relative reduction in mortality of between 22% and 33% (3-year OS of 71%–78% increased to 75%–84%).[14,15,16]

The completed, Intergroup trial 0089 (INT-0089 [EST-2288]) randomly assigned 3,794 patients with high-risk stage II or stage III colon cancer to one of four treatment arms:[17]

• The Mayo Clinic regimen administered for a total of six cycles.
• The Roswell Park regimen administered for a total of four cycles.
• The Mayo Clinic regimen administered with levamisole for six cycles.
• The Levamisole regimen administered for a total of 1 year.

Five-year OS ranged from 49% for the Mayo Clinic regimen with levamisole to 60% for the Mayo Clinic regimen, and there were no statistically significant differences among treatment arms.[17][Level of evidence: 1iiA] A preliminary report in November 1997 demonstrated a statistically significant advantage for OS for the Mayo Clinic regimen with levamisole compared with the levamisole regimen. This difference became insignificant with longer follow-up. Overall, grade 3 or greater toxicity occurred more frequently for the Mayo Clinic regimen and the Mayo Clinic regimen with levamisole. In addition, the Mayo Clinic regimen was significantly more toxic with levamisole than without levamisole. The death rate for all four regimens ranged from 0.5% to 1%. Because of its ease of use and its good toxicity profile, the Roswell Park regimen became the preferred adjuvant regimen used in the United States and was often the control arm in subsequent randomized studies.

In addition to INT-0089, multiple studies have refined the use of 5-FU-leucovorin in the adjuvant setting and can be summarized as follows:

• Levamisole is unnecessary when using leucovorin.[17]
• Treatment that includes 6 to 8 months of 5-FU-leucovorin is equivalent to 12 months.[18,19,20]
• Treatment that includes 24 weeks of adjuvant 5-FU-leucovorin is equivalent to 36 weeks of therapy.[21]
• High-dose leucovorin is equivalent to low-dose leucovorin.[22]
• A meta-analysis of seven trials revealed no significant difference in efficacy or toxicity among patients 70 years or younger compared with patients older than 70 years.[23]
• An infusional deGramont LV5FU2 schedule is safer than a bolus modified Mayo Clinic schedule of 5-FU-leucovorin.[21]

Chemotherapy regimens after 2000

Capecitabine is an oral fluoropyrimidine that undergoes a three-step enzymatic conversion to 5-FU with the last step occurring in the tumor cell. For patients with metastatic colon cancer, two studies have demonstrated the equivalence of capecitabine to 5-FU-leucovorin.[24,25] A multicenter European study compared capecitabine (1250 mg/m²) administered twice daily for days 1 to 14, then given every 21 days for eight cycles against the Mayo Clinic schedule of 5-FU and low-dose leucovorin for patients with stage III colon cancer.[26] The study demonstrated that disease-free survival (DFS) at 3 years is equivalent for patients receiving capecitabine or 5-FU-leucovorin (HR, 0.87; P < .001).[26][Level of evidence: 1iiDii] Hand-foot syndrome and hyperbilirubinemia were significantly more common for patients receiving capecitabine, but diarrhea, nausea or vomiting, stomatitis, alopecia, and neutropenia were significantly less common. Of patients receiving capecitabine, 57% required a dose modification. For patients with stage III colon cancer in whom treatment with 5-FU-leucovorin is planned, capecitabine is an equivalent alternative.

Oxaliplatin has significant activity when combined with 5-FU-leucovorin in patients with metastatic colorectal cancer. In the 2,246 patients with resected stage II or stage III colon cancer in the MOSAIC study, the toxic effects and efficacy of FOLFOX4 were compared with the same 5-FU-leucovorin regimen without oxaliplatin administered for 6 months.[27] The preliminary results of the study with 37 months of follow-up demonstrated a significant improvement in DFS at 3 years (77.8% vs. 72.9%, P = .01) in favor of FOLFOX4. When initially reported, there was no difference in OS.[6][Level of evidence: 1iiDii] Further follow-up at 6 years demonstrated that the OS for all patients (both stage II and stage III) entered into the study was not significantly different (OS = 78.5% vs. 76.0%; HR, 0.84; 95% CI, 0.71–1.00). On subset analysis, the 6-year OS in patients with stage III colon cancer was 72.9% in the patients receiving FOLFOX and 68.9% in the patients receiving 5-FU/LV (HR, 0.80; 95% CI, 0.65–0.97, P = .023).[6][Level of evidence: 1iiA] Patients treated with FOLFOX4 experienced more frequent toxic effects consisting mainly of neutropenia (41% >grade 3) and reversible peripheral sensorial neuropathy (12.4% >grade 3). FOLFOX has become the reference standard for the next generation of clinical trials for patients with stage III colon cancer.[6]

Current Clinical Trials

Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with stage III colon cancer. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site.

References:

1.	Bokey EL, Moore JW, Chapuis PH, et al.: Morbidity and mortality following laparoscopic-assisted right hemicolectomy for cancer. Dis Colon Rectum 39 (10 Suppl): S24-8, 1996.
2.	Franklin ME Jr, Rosenthal D, Abrego-Medina D, et al.: Prospective comparison of open vs. laparoscopic colon surgery for carcinoma. Five-year results. Dis Colon Rectum 39 (10 Suppl): S35-46, 1996.
3.	Fleshman JW, Nelson H, Peters WR, et al.: Early results of laparoscopic surgery for colorectal cancer. Retrospective analysis of 372 patients treated by Clinical Outcomes of Surgical Therapy (COST) Study Group. Dis Colon Rectum 39 (10 Suppl): S53-8, 1996.
4.	Schwenk W, Böhm B, Müller JM: Postoperative pain and fatigue after laparoscopic or conventional colorectal resections. A prospective randomized trial. Surg Endosc 12 (9): 1131-6, 1998.
5.	Weeks JC, Nelson H, Gelber S, et al.: Short-term quality-of-life outcomes following laparoscopic-assisted colectomy vs open colectomy for colon cancer: a randomized trial. JAMA 287 (3): 321-8, 2002.
6.	André T, Boni C, Navarro M, et al.: Improved overall survival with oxaliplatin, fluorouracil, and leucovorin as adjuvant treatment in stage II or III colon cancer in the MOSAIC trial. J Clin Oncol 27 (19): 3109-16, 2009.
7.	Rougier P, Nordlinger B: Large scale trial for adjuvant treatment in high risk resected colorectal cancers. Rationale to test the combination of loco-regional and systemic chemotherapy and to compare l-leucovorin + 5-FU to levamisole + 5-FU. Ann Oncol 4 (Suppl 2): 21-8, 1993.
8.	Panettiere FJ, Goodman PJ, Costanzi JJ, et al.: Adjuvant therapy in large bowel adenocarcinoma: long-term results of a Southwest Oncology Group Study. J Clin Oncol 6 (6): 947-54, 1988.
9.	Adjuvant therapy of colon cancer--results of a prospectively randomized trial. Gastrointestinal Tumor Study Group. N Engl J Med 310 (12): 737-43, 1984.
10.	Higgins GA Jr, Amadeo JH, McElhinney J, et al.: Efficacy of prolonged intermittent therapy with combined 5-fluorouracil and methyl-CCNU following resection for carcinoma of the large bowel. A Veterans Administration Surgical Oncology Group report. Cancer 53 (1): 1-8, 1984.
11.	Buyse M, Zeleniuch-Jacquotte A, Chalmers TC: Adjuvant therapy of colorectal cancer. Why we still don't know. JAMA 259 (24): 3571-8, 1988.
12.	Laurie JA, Moertel CG, Fleming TR, et al.: Surgical adjuvant therapy of large-bowel carcinoma: an evaluation of levamisole and the combination of levamisole and fluorouracil. The North Central Cancer Treatment Group and the Mayo Clinic. J Clin Oncol 7 (10): 1447-56, 1989.
13.	Moertel CG, Fleming TR, Macdonald JS, et al.: Levamisole and fluorouracil for adjuvant therapy of resected colon carcinoma. N Engl J Med 322 (6): 352-8, 1990.
14.	Wolmark N, Rockette H, Fisher B, et al.: The benefit of leucovorin-modulated fluorouracil as postoperative adjuvant therapy for primary colon cancer: results from National Surgical Adjuvant Breast and Bowel Project protocol C-03. J Clin Oncol 11 (10): 1879-87, 1993.
15.	Efficacy of adjuvant fluorouracil and folinic acid in colon cancer. International Multicentre Pooled Analysis of Colon Cancer Trials (IMPACT) investigators. Lancet 345 (8955): 939-44, 1995.
16.	O'Connell M, Mailliard J, Macdonald J, et al.: An intergroup trial of intensive course 5FU and low dose leucovorin as surgical adjuvant therapy for high risk colon cancer. [Abstract] Proceedings of the American Society of Clinical Oncology 12: A-552, 190, 1993.
17.	Haller DG, Catalano PJ, Macdonald JS, et al.: Phase III study of fluorouracil, leucovorin, and levamisole in high-risk stage II and III colon cancer: final report of Intergroup 0089. J Clin Oncol 23 (34): 8671-8, 2005.
18.	Wolmark N, Bryant J, Smith R, et al.: Adjuvant 5-fluorouracil and leucovorin with or without interferon alfa-2a in colon carcinoma: National Surgical Adjuvant Breast and Bowel Project protocol C-05. J Natl Cancer Inst 90 (23): 1810-6, 1998.
19.	Wolmark N, Rockette H, Mamounas E, et al.: Clinical trial to assess the relative efficacy of fluorouracil and leucovorin, fluorouracil and levamisole, and fluorouracil, leucovorin, and levamisole in patients with Dukes' B and C carcinoma of the colon: results from National Surgical Adjuvant Breast and Bowel Project C-04. J Clin Oncol 17 (11): 3553-9, 1999.
20.	Okuno SH, Woodhouse CL, Loprinzi CL, et al.: Phase III placebo-controlled clinical trial evaluation of glutamine for decreasing mucositis in patients receiving 5FU (fluorouracil)-base chemotherapy. [Abstract] Proceedings of the American Society of Clinical Oncology 17: A-256, 1998.
21.	Andre T, Colin P, Louvet C, et al.: Semimonthly versus monthly regimen of fluorouracil and leucovorin administered for 24 or 36 weeks as adjuvant therapy in stage II and III colon cancer: results of a randomized trial. J Clin Oncol 21 (15): 2896-903, 2003.
22.	Comparison of flourouracil with additional levamisole, higher-dose folinic acid, or both, as adjuvant chemotherapy for colorectal cancer: a randomised trial. QUASAR Collaborative Group. Lancet 355 (9215): 1588-96, 2000.
23.	Sargent DJ, Goldberg RM, Jacobson SD, et al.: A pooled analysis of adjuvant chemotherapy for resected colon cancer in elderly patients. N Engl J Med 345 (15): 1091-7, 2001.
24.	Van Cutsem E, Twelves C, Cassidy J, et al.: Oral capecitabine compared with intravenous fluorouracil plus leucovorin in patients with metastatic colorectal cancer: results of a large phase III study. J Clin Oncol 19 (21): 4097-106, 2001.
25.	Hoff PM, Ansari R, Batist G, et al.: Comparison of oral capecitabine versus intravenous fluorouracil plus leucovorin as first-line treatment in 605 patients with metastatic colorectal cancer: results of a randomized phase III study. J Clin Oncol 19 (8): 2282-92, 2001.
26.	Twelves C, Wong A, Nowacki MP, et al.: Capecitabine as adjuvant treatment for stage III colon cancer. N Engl J Med 352 (26): 2696-704, 2005.
27.	André T, Boni C, Mounedji-Boudiaf L, et al.: Oxaliplatin, fluorouracil, and leucovorin as adjuvant treatment for colon cancer. N Engl J Med 350 (23): 2343-51, 2004.

Stage IV and Recurrent Colon Cancer

Stage IV colon cancer denotes distant metastatic disease. Treatment of recurrent colon cancer depends on the sites of recurrent disease demonstrable by physical examination and/or radiographic studies. In addition to standard radiographic procedures, radioimmunoscintography may add clinical information that may affect management.[1] Such approaches have not led to improvements in long-term outcome measures such as survival.

Treatment options include the following:

1.	Surgical resection of locally recurrent cancer.
2.	Surgical resection and anastomosis or bypass of obstructing or bleeding primary lesions in selected metastatic cases.
3.	Resection of liver metastases in selected metastatic patients (5-year cure rate for resection of solitary or combination metastases exceeds 20%) or ablation in selected patients.[2,3,4,5,6,7,8,9,10,11]
4.	Resection of isolated pulmonary or ovarian metastases in selected patients.[12]
5.	Palliative radiation therapy.
6.	Palliative chemotherapy.
7.	Clinical trials evaluating new drugs and biological therapy.
8.	Clinical trials comparing various chemotherapy regimens or biological therapy, alone or in combination.

Liver Metastasis

Approximately 50% of colon cancer patients will be diagnosed with hepatic metastases, either at the time of initial presentation or as a result of disease recurrence. Although only a small proportion of patients with hepatic metastases are candidates for surgical resection, advances in tumor ablation techniques and in both regional and systemic chemotherapy administration provide for a number of treatment options.

Hepatic metastasis may be considered to be resectable based on the following:[5,7,13,14,15,16]

• Limited number of lesions.
• Intrahepatic locations of lesions.
• Lack of major vascular involvement.
• Absent or limited extrahepatic disease.
• Sufficient functional hepatic reserve.

For patients with hepatic metastasis considered to be resectable, a negative margin resection has resulted in 5-year survival rates of 25% to 40% in mostly nonrandomized studies, such as the NCCTG-934653 trial.[5,7,13,14,15,16] Improved surgical techniques and advances in preoperative imaging have allowed for better patient selection for resection.

Patients with hepatic metastases that are deemed unresectable will occasionally become candidates for resection if they have a good response to chemotherapy. These patients have 5-year survival rates similar to patients who initially had resectable disease.[17] Radiofrequency ablation has emerged as a safe technique (2% major morbidity and <1% mortality rate) that may provide for long-term tumor control.[18,19,20,21,22,23,24] Radiofrequency ablation and cryosurgical ablation [25,26,27,28] remain options for patients with tumors that cannot be resected and for patients who are not candidates for liver resection.

Other local ablative techniques that have been used to manage liver metastases include embolization and interstitial radiation therapy.[29,30] Patients with limited pulmonary metastases, and patients with both pulmonary and hepatic metastases, may also be considered for surgical resection, with 5-year survival possible in highly selected patients.[12,31,32]

The role of adjuvant chemotherapy after potentially curative resection of liver metastases is uncertain. A trial of hepatic arterial floxuridine and dexamethasone plus systemic fluorouracil (5-FU) and leucovorin compared to systemic 5-FU plus leucovorin alone showed improved 2-year progression-free survival (57% vs. 42%, P = .07) and overall survival (OS) (86% vs. 72%, P = .03) but did not show a significant statistical difference in median survival, compared with systemic 5-FU therapy alone. Median survival in the combined therapy arm was 72.2 months versus 59.3 months in the monotherapy arm (P = .21).[33][Level of evidence: 1iiA]

A second trial preoperatively randomly assigned 109 patients who had one to three potentially resectable colorectal hepatic metastases to either no further therapy or postoperative hepatic arterial floxuridine plus systemic 5-FU.[34] Of those randomly assigned patients, 27% were deemed ineligible at the time of surgery, which left only 75 patients evaluable for recurrence and survival. While liver recurrence was decreased, median or 4-year survival was not significantly different. Further studies are required to evaluate this treatment approach and to determine if more effective systemic combination chemotherapy alone may provide similar results compared with hepatic intra-arterial therapy plus systemic treatment.

Hepatic intra-arterial chemotherapy with floxuridine for liver metastases has produced higher overall response rates but no consistent improvement in survival when compared to systemic chemotherapy.[2,35,36,37,38,39] Controversy regarding the efficacy of regional chemotherapy led to initiation of a large multicenter phase III trial (CALGB-9481, now completed) of hepatic arterial infusion versus systemic chemotherapy. The use of the combination of intra-arterial chemotherapy with hepatic radiation therapy, especially employing focal radiation of metastatic lesions, is under evaluation.[40] Several studies show increased local toxic effects with hepatic infusional therapy, including liver function abnormalities and fatal biliary sclerosis.

Drug combinations described in this section include the following:

• The Arbeitsgemeinschaft Internische Onkologie (AIO) or German AIO regimen (folic acid, 5-FU, and irinotecan):
  • Irinotecan (100 mg/m²) administered as a 2-hour infusion on day 1; leucovorin (500 mg/m²) administered as a 2-hour infusion on day 1; followed by 5-FU (2,000 mg/m²) intravenous (IV) bolus via ambulatory pump administered for a period of 24 hours on a weekly basis four times a year (52 weeks).
• The CAPOX regimen:
  • Capecitabine (1000 mg/m²) twice a day on days 1 through 14 plus oxaliplatin (70 mg/m²) on days 1 and 8 every 3 weeks.
• The Douillard regimen (folic acid, 5-FU, and irinotecan):
  • Irinotecan (180 mg/m²) administered as a 2-hour infusion on day 1; leucovorin (200 mg/m²) administered as a 2-hour infusion on day 1 and day 2; followed by a loading dose of 5-FU (400 mg/m²) IV bolus, then 5-FU (600 mg/m²) via ambulatory pump administered for a period of 22 hours on day 1 and day 2 every 2 weeks.
• The FOLFOX4 regimen (oxaliplatin, leucovorin, and 5-FU):
  • Oxaliplatin (85 mg/m²) administered as a 2-hour infusion on day 1; leucovorin (200 mg/m²) administered as a 2-hour infusion on day 1 and day 2; followed by a loading dose of 5-FU (400 mg/m²) IV bolus, then 5-FU (600 mg/m²) administered via ambulatory pump for a period of 22 hours on day 1 and day 2 every 2 weeks.
• The FOLFOX6 regimen (oxaliplatin, leucovorin, and 5-FU):
  • Oxaliplatin (85–100 mg/m²) administered as a 2-hour infusion on day 1; leucovorin (400 mg/m²) administered as a 2-hour infusion on day 1; followed by a loading dose of 5-FU (400 mg/m²) IV bolus on day 1, then 5-FU (2,400–3,000 mg/m²) administered via ambulatory pump for a period of 46 hours every 2 weeks.
• The FOLFIRI regimen (folic acid, 5-FU, and irinotecan):
  • Irinotecan (180 mg/m²) administered as a 2-hour infusion on day 1; leucovorin (400 mg/m²) administered as a 2-hour infusion on day 1; followed by a loading dose of 5-FU (400 mg/m²) IV bolus administered on day 1, then 5-FU (2,400–3,000 mg/m²) administered via ambulatory pump for a period of 46 hours every 2 weeks.
• The FUFOX regimen:
  • Oxaliplatin (50 mg/m²) plus leucovorin (500 mg/m²) plus 5-FU (2000 mg/m²) as a 22-hour continuous infusion on days 1, 8, 22, and 29 every 36 days.
• The FUOX regimen:
  • Continuous infusion 5-FU (2250 mg/m²) during 48 hours on days 1, 8, 15, 22, 29 and 36 plus oxaliplatin (85 mg/m²) on days 1, 15, and 29 every 6 weeks.
• The IFL (or Saltz) regimen (irinotecan, 5-FU, and leucovorin):
  • Irinotecan (125 mg/m²), 5-FU (500 mg/m²) IV bolus, and leucovorin (20 mg/m²) IV bolus administered weekly for 4 out of 6 weeks.
• The XELOX regimen:
  • Oral capecitabine (1000 mg/m²) twice a day for 14 days plus oxaliplatin (130 mg/m²) on day 1 every 3 weeks.

Treatment of Patients With Stage IV Disease

Treatment of patients with recurrent or advanced colon cancer depends on the location of the disease. For patients with locally recurrent and/or liver-only and/or lung-only metastatic disease, surgical resection, if feasible, is the only potentially curative treatment.

Hepatic metastasis may be considered to be resectable based on the following:[5,7,13,14,15,16]

• Limited number of lesions.
• Intrahepatic locations of lesions.
• Lack of major vascular involvement.
• Absent or limited extrahepatic disease.
• Sufficient functional hepatic reserve.

For patients with hepatic metastasis considered to be resectable, a negative margin resection has been associated with 5-year survival rates of 25% to 40% in mostly nonrandomized studies.[41,42,43,44,45][Level of evidence: 3iiiDiv] Better surgical techniques and advances in preoperative imaging have improved patient selection for resection. In addition, multiple studies with multiagent chemotherapy have demonstrated that patients with metastatic disease isolated to the liver, which historically would be considered unresectable, can occasionally be made resectable after the administration of chemotherapy.[17]

Currently, there are seven active and approved drugs for patients with metastatic colorectal cancer:

• 5-FU.
• Capecitabine.
• Irinotecan.
• Oxaliplatin.
• Bevacizumab.
• Cetuximab.
• Panitumumab.

When 5-FU was the only active chemotherapy drug, trials in patients with locally advanced, unresectable, or metastatic disease demonstrated partial responses and prolongation of the time-to-progression (TTP) of disease [46,47] as well as improved survival and quality of life for patients receiving chemotherapy, compared with the best supportive care.[48,49,50] Several trials have analyzed the activity and toxic effects of various 5-FU-leucovorin regimens using different doses and administration schedules and showed essentially equivalent results with a median survival time in the 12-month range.[51] Prior to the advent of multiagent chemotherapy, two randomized studies demonstrated that capecitabine was associated with equivalent efficacy when compared with the Mayo Clinic regimen of 5-FU-leucovorin.[52,53][Level of evidence: 1iiA]

First-line Multiagent Chemotherapy

Three randomized studies demonstrated improved response rates, progression-free survival (PFS), and OS when irinotecan or oxaliplatin was combined with 5-FU-leucovorin.[54,55,56] An intergroup study (NCCTG-N9741) then compared IFL with FOLFOX4 in first-line treatment for patients with metastatic colorectal cancer. Patients assigned to FOLFOX4 experienced an improved PFS (median, 6.9 months vs. 8.7 months; P = .014; hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.61–0.89) and OS (15.0 months vs. 19.5 months, P = .001; HR, 0.66; 95% CI, 0.54–0.82) compared with patients randomly assigned to IFL.[Level of evidence: 1iiA] Subsequently, two studies compared FOLFOX with FOLFIRI, and patients were allowed to cross over upon progression on first-line therapy, respectively.[57,58][Level of evidence: 1iiDiii] PFS and OS were identical between the treatment arms in both studies. Since the publication of these studies, the use of either FOLFOX or FOLFIRI is considered acceptable for first-line treatment of patients with metastatic colorectal cancer.

The Bolus, Infusional, or Capecitabine with Camptosar-Celecoxib (BICC-C) trial evaluated several different irinotecan-based regimens in patients with previously untreated metastatic colorectal cancer: FOLFIRI, mIFL, and capecitabine/irinotecan (CAPIRI).[59] The study randomly assigned 430 patients and was closed early due to poor accrual. The patients who received FOLFIRI had a better PFS than the patients who received either mIFL (7.6 months vs. 5.9 months, P = .004) or CAPIRI (7.6 months vs. 5.8 months, P = .015). Patients who received CAPIRI had the highest grade 3 or higher rates of nausea, vomiting, diarrhea, dehydration, and hand-foot syndrome. After bevacizumab was approved, the BICC-C trial was amended, and an additional 117 patients were randomly assigned to receive FOLFIRI/bevacizumab or mIFL/bevacizumab. Although the primary endpoint, PFS, was not significantly different, patients receiving FOLFIRI/bevacizumab had a significantly better OS (not yet reached with a median follow-up of 22.6 months vs. 19.2 months, P = .007). When using an irinotecan-based regimen as first-line treatment of metastatic colorectal cancer, FOLFIRI is preferred.[59][Level of evidence: 1iiDiii] (Refer to the PDQ summary on Nausea and Vomiting and for information on diarrhea and dehydration, refer to the PDQ summary on Gastrointestinal Complications.)

Randomized, phase III trials have addressed the equivalence of substituting capecitabine for infusional 5-FU. Two phase III studies have evaluated FUOX versus CAPOX.[60,61] The AIO Colorectal Study Group randomly assigned 474 patients to either FUFOX or CAPOX. The median PFS was 7.1 months for the CAPOX arm and 8.0 months for the FUFOX arm (HR, 1.17; 95% CI, 0.96–1.43, P = .117), and the HR was in the prespecified equivalence range. The Spanish Cooperative Group randomly assigned 348 patients to CAPOX or FUOX.[60] The TTP was 8.9 months versus 9.5 months (P = .153) and met the prespecified range for noninferiority.[60][Level of evidence: 1iiDiii] When using an oxaliplatin-based regimen as first-line treatment of metastatic colorectal cancer, a CAPOX regimen is not inferior to a FUOX regimen.

The Addition of Targeted Therapy to Multiagent Chemotherapy

Bevacizumab

Patients with previously untreated metastatic colorectal cancer were randomly assigned to either IFL or IFL and bevacizumab.[62] The patients randomly assigned to IFL and bevacizumab experienced a significantly better PFS (10.6 months in the group given IFL and bevacizumab, as compared with 6.2 months in the group given IFL and placebo; HR for disease progression, 0.54; P < .001) and OS (20.3 months in the group given IFL and bevacizumab, as compared with 15.6 months in the group given IFL and placebo corresponding to an HR for death, 0.66; P < .001).[62]

Despite the lack of direct data, in standard practice, bevacizumab was added to FOLFOX as a standard first-line regimen based on the results of NCCTG-N9741.[63] Subsequently, in a randomized phase III study, patients with untreated, stage IV colorectal cancer were randomly assigned in a 2 × 2 factorial design to CAPOX versus FOLFOX4, then to bevacizumab versus placebo. PFS was the primary endpoint. In this trial, 1,401 patients were randomly assigned, and the median PFS was 9.4 months for patients receiving bevacizumab and 8.0 months for the patients receiving placebo (HR, 0.83; 97.5% confidence interval [CI] 0.72–0.95, P = .0023).[64][Level of evidence: 1iiDiii] Median OS was 21.3 months for patients receiving bevacizumab and 19.9 months for patients receiving placebo (HR, 0.89; 97.5% CI, 0.76–1.03, P = .077). The median PFS (intention-to-treat analysis) was 8.0 months in the pooled CAPOX-containing arms versus 8.5 months in the FOLFOX4-containing arms (HR, 1.04; 97.5% CI, 0.93–1.16), with the upper limit of the 97.5% CI being below the predefined noninferiority margin of 1.23.[64,65] The effect of bevacizumab on OS is likely to be less than what was seen in the original Hurwitz study.

Investigators from the Eastern Cooperative Oncology Group (ECOG) randomly assigned patients who had progressed on 5-FU-leucovorin and irinotecan to either FOLFOX or FOLFOX and bevacizumab. Patients randomly assigned to FOLFOX and bevacizumab experienced a statistically significant improvement in PFS (7.43 months vs. 4.7 months, HR, 0.61; P < .0001) and OS (12.9 months vs. 10.8 months, HR, 0.75; P = .0011).[66][Level of evidence: 1iiA] Based on these two studies, bevacizumab can reasonably be added to either FOLFIRI or FOLFOX for patients undergoing first-line treatment of metastatic colorectal cancer.

There are currently no completed randomized controlled studies evaluating whether continued use of bevacizumab in the second line or third line after progressing on a first-line bevacizumab regimen is worthwhile.

Cetuximab/panitumumab and second-line chemotherapy

Second-line chemotherapy with irinotecan in patients treated with 5-FU-leucovorin as first-line therapy demonstrated improved OS when compared to either infusional 5-FU or supportive care.[67,68,69,70] Similarly, a phase III trial randomly assigned patients who progressed on irinotecan and 5-FU-leucovorin to bolus and infusional 5-FU-leucovorin (LV5FU2), single-agent oxaliplatin, or FOLFOX4. The median TTP for FOLFOX4 versus LV5FU2 was 4.6 months versus 2.7 months (stratified log-rank test, 2-sided P < .001).[71][Level of evidence: 1iiDiii]

Cetuximab is a partially humanized monoclonal antibody against the epidermal growth factor receptor (EGFR). For patients who have progressed on irinotecan-containing regimens, a randomized phase II study was performed of either cetuximab or irinotecan and cetuximab. The median TTP for patients receiving cetuximab was 1.5 months, and the median TTP for patients receiving irinotecan and cetuximab was 4.2 months.[72][Level of evidence: 3iiiDiv] On the basis of this study, cetuximab was approved for use in patients with metastatic colorectal cancer refractory to 5-FU and irinotecan.

The Crystal Study (NCT00154102) randomly assigned 1,198 patients with stage IV colorectal cancer to FOLFIRI with or without cetuximab.[73] The addition of cetuximab was associated with an improved PFS (HR, 0.85; 95% CI, 0.72–0.99, P = .048 by a stratified log rank test), but not OS.[73][Level of Evidence: 1iiDii] Retrospective studies of patients with metastatic colorectal cancer have suggested that responses to anti-EGFR antibody therapy are confined to patients with tumors that harbor wild types of KRAS (i.e., lack activating mutations at codon 12 or 13 of the KRAS gene). A subset analysis evaluating efficacy vis a vis KRAS status was done in patients enrolled on the Crystal Study. There was a significant interaction for KRAS mutation status and treatment for tumor response (P = .03) but not for PFS (P = .07). Among patients with KRAS wild-type tumors, the HR favored the FOLFIRI/cetuximab group (HR, 0.68; 95% CI, 0.50–0.94).

Importantly, patients with mutant KRAS tumors may experience worse outcome when cetuximab is added to multiagent chemotherapy regimens containing bevacizumab. In a randomized trial, patients with metastatic colorectal cancer received capecitabine/oxaliplatin/bevacizumab with or without cetuximab. The median PFS was 9.4 months in the group receiving cetuximab and 10.7 months in the group not receiving cetuximab (P = .01). In a subset analysis, cetuximab-treated patients with tumors bearing a mutated KRAS gene had significantly decreased PFS compared with cetuximab-treated patients with wild-type KRAS tumors (8.1 months vs. 10.5 months; P = .04). Cetuximab-treated patients with mutated KRAS tumors had a significantly shorter PFS compared with patients with mutated KRAS tumors not receiving cetuximab (8.1 months vs. 12.5 months; P = .003) as well as OS (17.2 months vs. 24.9 months; P = .03).[74][Level of evidence: 1iiDiii]

Panitumumab is a fully humanized antibody against the EGFR. In a phase III trial, patients with chemotherapy refractory colorectal cancer were randomly assigned to panitumumab or best supportive care. Patients receiving panitumumab experienced an improved PFS (8 weeks vs. 7.3 weeks, HR, 0.54; 95% CI, 0.44–0.66; P <.0001).[75][Level of evidence: 1iiDiii] There was no difference in OS, which was thought to be the result of 76% of patients on best supportive care crossing over to panitumumab. The FDA-approved panitumumab for use in patients with metastatic colorectal cancer refractory to chemotherapy.[75]

In the PRIME (NCT00364013) study, 1,183 patients were randomly assigned to FOLFOX4 with or without panitumumab as first-line therapy for metastatic colorectal cancer.[76] The study was amended to enlarge the sample size to address patients with the KRAS wild-type tumors and patients with mutant KRAS tumors separately. For patients with KRAS wild-type tumors, a statistically significant improvement in PFS was observed in those who received panitumumab-FOLFOX4 compared with those who received only FOLFOX4 (HR, 0.80; 95% CI, 0.66–0.97; P = .02, stratified log-rank test).[76][Level of evidence: 1iiDiii] Median PFS was 9.6 months (95% CI, 9.2 months–11.1 months) for patients who received panitumumab-FOLFOX4 and 8.0 months (95% CI, 7.5 months–9.3 months) for patients who received FOLFOX4. OS was not significantly different between the groups (HR, 0.83; 95% CI, 0.67–1.02; P = .072). For patients with mutant KRAS tumors, there was worse PFS with the addition of panitumumab (HR, 1.29; 95% CI, 1.04–1.62; P = .02, stratified log-rank test). Median PFS was 7.3 months (95% CI, 6.3 months–8.0 months) for panitumumab-FOLFOX4 and 8.8 months (95% CI, 7.7 months–9.4 months) for FOLFOX4 alone.

Similarly, the addition of panitumumab to a regimen of FOLFOX/bevacizumab resulted in a worse PFS and worse toxicity compared to a regimen of FOLFOX/bevacizumab alone in patients not selected for KRAS mutation in metastatic colon cancer (11.4 months vs. 10.0 months, HR, 1.27; 95% CI, 1.06–1.52).[77][Level of evidence: 1iiDiii]

In another study (NCT00339183), patients with metastatic colorectal cancer who had already received a fluoropyrimidine regimen were randomly assigned to either FOLFIRI or FOLFIRI plus panitumumab.[78] In a post hoc analysis, patients with KRAS wild-type tumors experienced a statistically significant PFS advantage (HR, 0.73; 95% CI, 0.59–0.90; P = .004, stratified log-rank).[78][Level of evidence: 1iiDiii] Median PFS was 5.9 months (95% CI, 5.5 months–6.7 months) for panitumumab-FOLFIRI and 3.9 months (95% CI, 3.7 months–5.3 months) for FOLFIRI alone. OS was not significantly different. Patients with mutant KRAS tumors experienced no benefit from the addition of panitumumab.

The Medical Research Council (MRC) (UKM-MRC-COIN-CR10 [NCT00182715] or COIN trial) sought to answer the question of whether adding cetuximab to combination chemotherapy with a fluoropyrimidine and oxaliplatin in first-line treatment for patients with first-line KRAS wild-type tumors was beneficial.[79,80] In addition, the MRC sought to evaluate the effect of intermittent chemotherapy versus continuous chemotherapy. The 1,630 patients were randomly assigned to three treatment groups:

• Arm A: fluoropyrimidine/oxaliplatin.
• Arm B: fluoropyrimidine/oxaliplatin/cetuximab.
• Arm C: intermittent fluorpyrimidine/oxaliplatin.

The comparisons between arms A and B and arms A and C were analyzed and published separately.[79,80]

In patients with KRAS wild-type tumors (arm A, n = 367; arm B, n = 362), OS did not differ between treatment groups (median survival, 17.9 months [interquartile range (IQR) 10.3–29.2] in the control group vs. 17.0 months [IQR, 9.4–30.1] in the cetuximab group; HR, 1.04; 95% CI, 0.87–1.23, P = .67). Similarly, there was no effect on PFS (8.6 months [IQR, 5.0–12.5] in the control group vs. 8.6 months [IQR, 5.1–13.8] in the cetuximab group; HR, 0.96; 0.82–1.12, P = .60).[79,80][Level of evidence: 1iiA] The reasons for lack of benefit in adding cetuximab are unclear. Subset analyses suggest that the use of capecitabine was associated with an inferior outcome, and the use of second-line therapy was less in patients treated with cetuximab.

There was no difference between the continuously treated patients (arm A) and the intermittently treated patients (arm C). Median survival in the intent-to-treat population (n = 815 in both groups) was 15.8 months (IQR, 9.4–26.1) in arm A and 14.4 months (IQR, 8.0–24.7) in arm C (HR, 1.084; 80% CI, 1.008–1.165). In the per-protocol population, which included only those patients who were free from progression at 12 weeks and randomly assigned to continue treatment or go on a chemotherapy holiday (arm A, n = 467; arm C, n = 511), median survival was 19.6 months (IQR, 13.0–28.1) in arm A and 18.0 months (IQR, 12.1–29.3) in arm C (HR, 1.087, 95% CI, 0.986–1.198). The upper limits of CIs for HRs in both analyses were greater than the predefined noninferiority boundary. While intermittent chemotherapy was not deemed noninferior, there appeared to be clinically insignificant differences in patient outcomes.

Current Clinical Trials

Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with stage IV colon cancer and recurrent colon cancer. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site.

References:

1.	Serafini AN, Klein JL, Wolff BG, et al.: Radioimmunoscintigraphy of recurrent, metastatic, or occult colorectal cancer with technetium 99m-labeled totally human monoclonal antibody 88BV59: results of pivotal, phase III multicenter studies. J Clin Oncol 16 (5): 1777-87, 1998.
2.	Wagman LD, Kemeny MM, Leong L, et al.: A prospective, randomized evaluation of the treatment of colorectal cancer metastatic to the liver. J Clin Oncol 8 (11): 1885-93, 1990.
3.	Scheele J, Stangl R, Altendorf-Hofmann A: Hepatic metastases from colorectal carcinoma: impact of surgical resection on the natural history. Br J Surg 77 (11): 1241-6, 1990.
4.	Scheele J, Stangl R, Altendorf-Hofmann A, et al.: Indicators of prognosis after hepatic resection for colorectal secondaries. Surgery 110 (1): 13-29, 1991.
5.	Adson MA, van Heerden JA, Adson MH, et al.: Resection of hepatic metastases from colorectal cancer. Arch Surg 119 (6): 647-51, 1984.
6.	Coppa GF, Eng K, Ranson JH, et al.: Hepatic resection for metastatic colon and rectal cancer. An evaluation of preoperative and postoperative factors. Ann Surg 202 (2): 203-8, 1985.
7.	Gayowski TJ, Iwatsuki S, Madariaga JR, et al.: Experience in hepatic resection for metastatic colorectal cancer: analysis of clinical and pathologic risk factors. Surgery 116 (4): 703-10; discussion 710-1, 1994.
8.	Fernández-Trigo V, Shamsa F, Sugarbaker PH: Repeat liver resections from colorectal metastasis. Repeat Hepatic Metastases Registry. Surgery 117 (3): 296-304, 1995.
9.	Jaeck D, Bachellier P, Guiguet M, et al.: Long-term survival following resection of colorectal hepatic metastases. Association Française de Chirurgie. Br J Surg 84 (7): 977-80, 1997.
10.	Taylor M, Forster J, Langer B, et al.: A study of prognostic factors for hepatic resection for colorectal metastases. Am J Surg 173 (6): 467-71, 1997.
11.	Elias D, Cavalcanti A, Sabourin JC, et al.: Resection of liver metastases from colorectal cancer: the real impact of the surgical margin. Eur J Surg Oncol 24 (3): 174-9, 1998.
12.	Girard P, Ducreux M, Baldeyrou P, et al.: Surgery for lung metastases from colorectal cancer: analysis of prognostic factors. J Clin Oncol 14 (7): 2047-53, 1996.
13.	Hughes KS, Simon R, Songhorabodi S, et al.: Resection of the liver for colorectal carcinoma metastases: a multi-institutional study of patterns of recurrence. Surgery 100 (2): 278-84, 1986.
14.	Schlag P, Hohenberger P, Herfarth C: Resection of liver metastases in colorectal cancer--competitive analysis of treatment results in synchronous versus metachronous metastases. Eur J Surg Oncol 16 (4): 360-5, 1990.
15.	Rosen CB, Nagorney DM, Taswell HF, et al.: Perioperative blood transfusion and determinants of survival after liver resection for metastatic colorectal carcinoma. Ann Surg 216 (4): 493-504; discussion 504-5, 1992.
16.	Fong Y, Fortner J, Sun RL, et al.: Clinical score for predicting recurrence after hepatic resection for metastatic colorectal cancer: analysis of 1001 consecutive cases. Ann Surg 230 (3): 309-18; discussion 318-21, 1999.
17.	Leonard GD, Brenner B, Kemeny NE: Neoadjuvant chemotherapy before liver resection for patients with unresectable liver metastases from colorectal carcinoma. J Clin Oncol 23 (9): 2038-48, 2005.
18.	Rossi S, Buscarini E, Garbagnati F, et al.: Percutaneous treatment of small hepatic tumors by an expandable RF needle electrode. AJR Am J Roentgenol 170 (4): 1015-22, 1998.
19.	Solbiati L, Livraghi T, Goldberg SN, et al.: Percutaneous radio-frequency ablation of hepatic metastases from colorectal cancer: long-term results in 117 patients. Radiology 221 (1): 159-66, 2001.
20.	Lencioni R, Goletti O, Armillotta N, et al.: Radio-frequency thermal ablation of liver metastases with a cooled-tip electrode needle: results of a pilot clinical trial. Eur Radiol 8 (7): 1205-11, 1998.
21.	Curley SA, Izzo F, Delrio P, et al.: Radiofrequency ablation of unresectable primary and metastatic hepatic malignancies: results in 123 patients. Ann Surg 230 (1): 1-8, 1999.
22.	Oshowo A, Gillams A, Harrison E, et al.: Comparison of resection and radiofrequency ablation for treatment of solitary colorectal liver metastases. Br J Surg 90 (10): 1240-3, 2003.
23.	Livraghi T, Solbiati L, Meloni F, et al.: Percutaneous radiofrequency ablation of liver metastases in potential candidates for resection: the "test-of-time approach". Cancer 97 (12): 3027-35, 2003.
24.	Pawlik TM, Izzo F, Cohen DS, et al.: Combined resection and radiofrequency ablation for advanced hepatic malignancies: results in 172 patients. Ann Surg Oncol 10 (9): 1059-69, 2003.
25.	Jarnagin WR, Fong Y, Ky A, et al.: Liver resection for metastatic colorectal cancer: assessing the risk of occult irresectable disease. J Am Coll Surg 188 (1): 33-42, 1999.
26.	Ravikumar TS, Kaleya R, Kishinevsky A: Surgical ablative therapy of liver tumors. Cancer: Principles and Practice of Oncology Updates 14 (3): 1-12, 2000.
27.	Seifert JK, Morris DL: Prognostic factors after cryotherapy for hepatic metastases from colorectal cancer. Ann Surg 228 (2): 201-8, 1998.
28.	Bageacu S, Kaczmarek D, Lacroix M, et al.: Cryosurgery for resectable and unresectable hepatic metastases from colorectal cancer. Eur J Surg Oncol 33 (5): 590-6, 2007.
29.	Thomas DS, Nauta RJ, Rodgers JE, et al.: Intraoperative high-dose rate interstitial irradiation of hepatic metastases from colorectal carcinoma. Results of a phase I-II trial. Cancer 71 (6): 1977-81, 1993.
30.	Ravikumar TS: Interstitial therapies for liver tumors. Surg Oncol Clin N Am 5 (2): 365-77, 1996.
31.	McAfee MK, Allen MS, Trastek VF, et al.: Colorectal lung metastases: results of surgical excision. Ann Thorac Surg 53 (5): 780-5; discussion 785-6, 1992.
32.	Headrick JR, Miller DL, Nagorney DM, et al.: Surgical treatment of hepatic and pulmonary metastases from colon cancer. Ann Thorac Surg 71 (3): 975-9; discussion 979-80, 2001.
33.	Kemeny N, Huang Y, Cohen AM, et al.: Hepatic arterial infusion of chemotherapy after resection of hepatic metastases from colorectal cancer. N Engl J Med 341 (27): 2039-48, 1999.
34.	Kemeny MM, Adak S, Gray B, et al.: Combined-modality treatment for resectable metastatic colorectal carcinoma to the liver: surgical resection of hepatic metastases in combination with continuous infusion of chemotherapy--an intergroup study. J Clin Oncol 20 (6): 1499-505, 2002.
35.	Kemeny N, Daly J, Reichman B, et al.: Intrahepatic or systemic infusion of fluorodeoxyuridine in patients with liver metastases from colorectal carcinoma. A randomized trial. Ann Intern Med 107 (4): 459-65, 1987.
36.	Chang AE, Schneider PD, Sugarbaker PH, et al.: A prospective randomized trial of regional versus systemic continuous 5-fluorodeoxyuridine chemotherapy in the treatment of colorectal liver metastases. Ann Surg 206 (6): 685-93, 1987.
37.	Rougier P, Laplanche A, Huguier M, et al.: Hepatic arterial infusion of floxuridine in patients with liver metastases from colorectal carcinoma: long-term results of a prospective randomized trial. J Clin Oncol 10 (7): 1112-8, 1992.
38.	Kemeny N, Cohen A, Seiter K, et al.: Randomized trial of hepatic arterial floxuridine, mitomycin, and carmustine versus floxuridine alone in previously treated patients with liver metastases from colorectal cancer. J Clin Oncol 11 (2): 330-5, 1993.
39.	Reappraisal of hepatic arterial infusion in the treatment of nonresectable liver metastases from colorectal cancer. Meta-Analysis Group in Cancer. J Natl Cancer Inst 88 (5): 252-8, 1996.
40.	McGinn CJ, Lawrence TS: Clinical Results of the Combination of Radiation and Fluoropyrimidines in the Treatment of Intrahepatic Cancer. Semin Radiat Oncol 7 (4): 313-323, 1997.
41.	Weeks JC, Nelson H, Gelber S, et al.: Short-term quality-of-life outcomes following laparoscopic-assisted colectomy vs open colectomy for colon cancer: a randomized trial. JAMA 287 (3): 321-8, 2002.
42.	Higgins GA Jr, Amadeo JH, McElhinney J, et al.: Efficacy of prolonged intermittent therapy with combined 5-fluorouracil and methyl-CCNU following resection for carcinoma of the large bowel. A Veterans Administration Surgical Oncology Group report. Cancer 53 (1): 1-8, 1984.
43.	Buyse M, Zeleniuch-Jacquotte A, Chalmers TC: Adjuvant therapy of colorectal cancer. Why we still don't know. JAMA 259 (24): 3571-8, 1988.
44.	Laurie JA, Moertel CG, Fleming TR, et al.: Surgical adjuvant therapy of large-bowel carcinoma: an evaluation of levamisole and the combination of levamisole and fluorouracil. The North Central Cancer Treatment Group and the Mayo Clinic. J Clin Oncol 7 (10): 1447-56, 1989.
45.	Moertel CG, Fleming TR, Macdonald JS, et al.: Levamisole and fluorouracil for adjuvant therapy of resected colon carcinoma. N Engl J Med 322 (6): 352-8, 1990.
46.	Petrelli N, Herrera L, Rustum Y, et al.: A prospective randomized trial of 5-fluorouracil versus 5-fluorouracil and high-dose leucovorin versus 5-fluorouracil and methotrexate in previously untreated patients with advanced colorectal carcinoma. J Clin Oncol 5 (10): 1559-65, 1987.
47.	Petrelli N, Douglass HO Jr, Herrera L, et al.: The modulation of fluorouracil with leucovorin in metastatic colorectal carcinoma: a prospective randomized phase III trial. Gastrointestinal Tumor Study Group. J Clin Oncol 7 (10): 1419-26, 1989.
48.	Scheithauer W, Rosen H, Kornek GV, et al.: Randomised comparison of combination chemotherapy plus supportive care with supportive care alone in patients with metastatic colorectal cancer. BMJ 306 (6880): 752-5, 1993.
49.	Expectancy or primary chemotherapy in patients with advanced asymptomatic colorectal cancer: a randomized trial. Nordic Gastrointestinal Tumor Adjuvant Therapy Group. J Clin Oncol 10 (6): 904-11, 1992.
50.	Buyse M, Thirion P, Carlson RW, et al.: Relation between tumour response to first-line chemotherapy and survival in advanced colorectal cancer: a meta-analysis. Meta-Analysis Group in Cancer. Lancet 356 (9227): 373-8, 2000.
51.	Leichman CG, Fleming TR, Muggia FM, et al.: Phase II study of fluorouracil and its modulation in advanced colorectal cancer: a Southwest Oncology Group study. J Clin Oncol 13 (6): 1303-11, 1995.
52.	Van Cutsem E, Twelves C, Cassidy J, et al.: Oral capecitabine compared with intravenous fluorouracil plus leucovorin in patients with metastatic colorectal cancer: results of a large phase III study. J Clin Oncol 19 (21): 4097-106, 2001.
53.	Hoff PM, Ansari R, Batist G, et al.: Comparison of oral capecitabine versus intravenous fluorouracil plus leucovorin as first-line treatment in 605 patients with metastatic colorectal cancer: results of a randomized phase III study. J Clin Oncol 19 (8): 2282-92, 2001.
54.	Saltz LB, Cox JV, Blanke C, et al.: Irinotecan plus fluorouracil and leucovorin for metastatic colorectal cancer. Irinotecan Study Group. N Engl J Med 343 (13): 905-14, 2000.
55.	de Gramont A, Figer A, Seymour M, et al.: Leucovorin and fluorouracil with or without oxaliplatin as first-line treatment in advanced colorectal cancer. J Clin Oncol 18 (16): 2938-47, 2000.
56.	Douillard JY, Cunningham D, Roth AD, et al.: Irinotecan combined with fluorouracil compared with fluorouracil alone as first-line treatment for metastatic colorectal cancer: a multicentre randomised trial. Lancet 355 (9209): 1041-7, 2000.
57.	Tournigand C, André T, Achille E, et al.: FOLFIRI followed by FOLFOX6 or the reverse sequence in advanced colorectal cancer: a randomized GERCOR study. J Clin Oncol 22 (2): 229-37, 2004.
58.	Colucci G, Gebbia V, Paoletti G, et al.: Phase III randomized trial of FOLFIRI versus FOLFOX4 in the treatment of advanced colorectal cancer: a multicenter study of the Gruppo Oncologico Dell'Italia Meridionale. J Clin Oncol 23 (22): 4866-75, 2005.
59.	Fuchs CS, Marshall J, Mitchell E, et al.: Randomized, controlled trial of irinotecan plus infusional, bolus, or oral fluoropyrimidines in first-line treatment of metastatic colorectal cancer: results from the BICC-C Study. J Clin Oncol 25 (30): 4779-86, 2007.
60.	Díaz-Rubio E, Tabernero J, Gómez-España A, et al.: Phase III study of capecitabine plus oxaliplatin compared with continuous-infusion fluorouracil plus oxaliplatin as first-line therapy in metastatic colorectal cancer: final report of the Spanish Cooperative Group for the Treatment of Digestive Tumors Trial. J Clin Oncol 25 (27): 4224-30, 2007.
61.	Porschen R, Arkenau HT, Kubicka S, et al.: Phase III study of capecitabine plus oxaliplatin compared with fluorouracil and leucovorin plus oxaliplatin in metastatic colorectal cancer: a final report of the AIO Colorectal Study Group. J Clin Oncol 25 (27): 4217-23, 2007.
62.	Hurwitz H, Fehrenbacher L, Novotny W, et al.: Bevacizumab plus irinotecan, fluorouracil, and leucovorin for metastatic colorectal cancer. N Engl J Med 350 (23): 2335-42, 2004.
63.	Sanoff HK, Sargent DJ, Campbell ME, et al.: Five-year data and prognostic factor analysis of oxaliplatin and irinotecan combinations for advanced colorectal cancer: N9741. J Clin Oncol 26 (35): 5721-7, 2008.
64.	Saltz LB, Clarke S, Díaz-Rubio E, et al.: Bevacizumab in combination with oxaliplatin-based chemotherapy as first-line therapy in metastatic colorectal cancer: a randomized phase III study. J Clin Oncol 26 (12): 2013-9, 2008.
65.	Cassidy J, Clarke S, Díaz-Rubio E, et al.: Randomized phase III study of capecitabine plus oxaliplatin compared with fluorouracil/folinic acid plus oxaliplatin as first-line therapy for metastatic colorectal cancer. J Clin Oncol 26 (12): 2006-12, 2008.
66.	Giantonio BJ, Catalano PJ, Meropol NJ, et al.: High-dose bevacizumab improves survival when combined with FOLFOX4 in previously treated advanced colorectal cancer: results from the Eastern Cooperative Oncology Group (ECOG) study E3200. [Abstract] J Clin Oncol 23 (Suppl 16): A-2, 1s, 2005.
67.	Rothenberg ML, Eckardt JR, Kuhn JG, et al.: Phase II trial of irinotecan in patients with progressive or rapidly recurrent colorectal cancer. J Clin Oncol 14 (4): 1128-35, 1996.
68.	Conti JA, Kemeny NE, Saltz LB, et al.: Irinotecan is an active agent in untreated patients with metastatic colorectal cancer. J Clin Oncol 14 (3): 709-15, 1996.
69.	Rougier P, Van Cutsem E, Bajetta E, et al.: Randomised trial of irinotecan versus fluorouracil by continuous infusion after fluorouracil failure in patients with metastatic colorectal cancer. Lancet 352 (9138): 1407-12, 1998.
70.	Cunningham D, Pyrhönen S, James RD, et al.: Randomised trial of irinotecan plus supportive care versus supportive care alone after fluorouracil failure for patients with metastatic colorectal cancer. Lancet 352 (9138): 1413-8, 1998.
71.	Rothenberg ML, Oza AM, Bigelow RH, et al.: Superiority of oxaliplatin and fluorouracil-leucovorin compared with either therapy alone in patients with progressive colorectal cancer after irinotecan and fluorouracil-leucovorin: interim results of a phase III trial. J Clin Oncol 21 (11): 2059-69, 2003.
72.	Cunningham D, Humblet Y, Siena S, et al.: Cetuximab monotherapy and cetuximab plus irinotecan in irinotecan-refractory metastatic colorectal cancer. N Engl J Med 351 (4): 337-45, 2004.
73.	Van Cutsem E, Köhne CH, Hitre E, et al.: Cetuximab and chemotherapy as initial treatment for metastatic colorectal cancer. N Engl J Med 360 (14): 1408-17, 2009.
74.	Tol J, Koopman M, Cats A, et al.: Chemotherapy, bevacizumab, and cetuximab in metastatic colorectal cancer. N Engl J Med 360 (6): 563-72, 2009.
75.	Van Cutsem E, Peeters M, Siena S, et al.: Open-label phase III trial of panitumumab plus best supportive care compared with best supportive care alone in patients with chemotherapy-refractory metastatic colorectal cancer. J Clin Oncol 25 (13): 1658-64, 2007.
76.	Douillard JY, Siena S, Cassidy J, et al.: Randomized, phase III trial of panitumumab with infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX4) versus FOLFOX4 alone as first-line treatment in patients with previously untreated metastatic colorectal cancer: the PRIME study. J Clin Oncol 28 (31): 4697-705, 2010.
77.	Hecht JR, Mitchell E, Chidiac T, et al.: A randomized phase IIIB trial of chemotherapy, bevacizumab, and panitumumab compared with chemotherapy and bevacizumab alone for metastatic colorectal cancer. J Clin Oncol 27 (5): 672-80, 2009.
78.	Peeters M, Price TJ, Cervantes A, et al.: Randomized phase III study of panitumumab with fluorouracil, leucovorin, and irinotecan (FOLFIRI) compared with FOLFIRI alone as second-line treatment in patients with metastatic colorectal cancer. J Clin Oncol 28 (31): 4706-13, 2010.
79.	Maughan TS, Adams RA, Smith CG, et al.: Addition of cetuximab to oxaliplatin-based first-line combination chemotherapy for treatment of advanced colorectal cancer: results of the randomised phase 3 MRC COIN trial. Lancet 377 (9783): 2103-14, 2011.
80.	Adams RA, Meade AM, Seymour MT, et al.: Intermittent versus continuous oxaliplatin and fluoropyrimidine combination chemotherapy for first-line treatment of advanced colorectal cancer: results of the randomised phase 3 MRC COIN trial. Lancet Oncol 12 (7): 642-53, 2011.

Changes to This Summary (07 / 17 / 2012)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Editorial changes were made to this summary.

About This PDQ Summary

Purpose of This Summary

This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about the treatment of colon cancer. It is intended as a resource to inform and assist clinicians who care for cancer patients. It does not provide formal guidelines or recommendations for making health care decisions.

Reviewers and Updates

This summary is reviewed regularly and updated as necessary by the PDQ Adult Treatment Editorial Board, which is editorially independent of the National Cancer Institute (NCI). The summary reflects an independent review of the literature and does not represent a policy statement of NCI or the National Institutes of Health (NIH).

Board members review recently published articles each month to determine whether an article should:

• be discussed at a meeting,
• be cited with text, or
• replace or update an existing article that is already cited.

Changes to the summaries are made through a consensus process in which Board members evaluate the strength of the evidence in the published articles and determine how the article should be included in the summary.

The lead reviewers for Colon Cancer Treatment are:

• Russell S. Berman, MD (New York University School of Medicine)
• David P. Ryan, MD (Massachusetts General Hospital)
• Jennifer Wo, MD (Massachusetts General Hospital)

Any comments or questions about the summary content should be submitted to Cancer.gov through the Web site's Contact Form. Do not contact the individual Board Members with questions or comments about the summaries. Board members will not respond to individual inquiries.

Levels of Evidence

Some of the reference citations in this summary are accompanied by a level-of-evidence designation. These designations are intended to help readers assess the strength of the evidence supporting the use of specific interventions or approaches. The PDQ Adult Treatment Editorial Board uses a formal evidence ranking system in developing its level-of-evidence designations.

Permission to Use This Summary

PDQ is a registered trademark. Although the content of PDQ documents can be used freely as text, it cannot be identified as an NCI PDQ cancer information summary unless it is presented in its entirety and is regularly updated. However, an author would be permitted to write a sentence such as "NCI's PDQ cancer information summary about breast cancer prevention states the risks succinctly: [include excerpt from the summary]."

The preferred citation for this PDQ summary is:

National Cancer Institute: PDQ® Colon Cancer Treatment. Bethesda, MD: National Cancer Institute. Date last modified <MM/DD/YYYY>. Available at: http://cancer.gov/cancertopics/pdq/treatment/colon/HealthProfessional. Accessed <MM/DD/YYYY>.

Images in this summary are used with permission of the author(s), artist, and/or publisher for use within the PDQ summaries only. Permission to use images outside the context of PDQ information must be obtained from the owner(s) and cannot be granted by the National Cancer Institute. Information about using the illustrations in this summary, along with many other cancer-related images, is available in Visuals Online, a collection of over 2,000 scientific images.

Disclaimer

Based on the strength of the available evidence, treatment options may be described as either "standard" or "under clinical evaluation." These classifications should not be used as a basis for insurance reimbursement determinations. More information on insurance coverage is available on Cancer.gov on the Coping with Cancer: Financial, Insurance, and Legal Information page.

Contact Us

More information about contacting us or receiving help with the Cancer.gov Web site can be found on our Contact Us for Help page. Questions can also be submitted to Cancer.gov through the Web site's Contact Form.

Get More Information From NCI

Call 1-800-4-CANCER

For more information, U.S. residents may call the National Cancer Institute's (NCI's) Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 8:00 a.m. to 8:00 p.m., Eastern Time. A trained Cancer Information Specialist is available to answer your questions.

Chat online

The NCI's LiveHelp® online chat service provides Internet users with the ability to chat online with an Information Specialist. The service is available from 8:00 a.m. to 11:00 p.m. Eastern time, Monday through Friday. Information Specialists can help Internet users find information on NCI Web sites and answer questions about cancer.

Write to us

For more information from the NCI, please write to this address:

NCI Public Inquiries Office

Suite 3036A

6116 Executive Boulevard, MSC8322

Bethesda, MD 20892-8322

Search the NCI Web site

The NCI Web site provides online access to information on cancer, clinical trials, and other Web sites and organizations that offer support and resources for cancer patients and their families. For a quick search, use the search box in the upper right corner of each Web page. The results for a wide range of search terms will include a list of "Best Bets," editorially chosen Web pages that are most closely related to the search term entered.

There are also many other places to get materials and information about cancer treatment and services. Hospitals in your area may have information about local and regional agencies that have information on finances, getting to and from treatment, receiving care at home, and dealing with problems related to cancer treatment.

Find Publications

The NCI has booklets and other materials for patients, health professionals, and the public. These publications discuss types of cancer, methods of cancer treatment, coping with cancer, and clinical trials. Some publications provide information on tests for cancer, cancer causes and prevention, cancer statistics, and NCI research activities. NCI materials on these and other topics may be ordered online or printed directly from the NCI Publications Locator. These materials can also be ordered by telephone from the Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237).

Last Revised: 2012-07-17