The Impact of COVID-19 on Colorectal Cancer Screening

Audrey Calderwood, MD

There are people with cancer who have not been diagnosed and are not getting the care they need.

Audrey H. Calderwood, MD, MS

Colorectal cancer screening, often done in a health care setting using endoscopic procedures such as colonoscopy, was not an exception to the sharp drop in routine cancer screenings seen during the COVID-19 pandemic. As part of an academic medical center, researchers at Dartmouth's and Dartmouth-Hitchcock’s Norris Cotton Cancer Center took an interest in looking more closely at the impact of the pandemic on endoscopy volumes from diverse practices across the U.S. 

What the data show

Led by Audrey H. Calderwood, MD, MS, director of Dartmouth-Hitchcock’s (D-H's) Comprehensive Gastroenterology Center, researchers analyzed data on endoscopy procedures from the GI Quality Improvement Consortium (GIQuIC) registry. “We compared data collected during the pandemic, March to September of 2020, to data collected before the pandemic, January 2019 to February 2020 and found a dramatic reduction in both esophagogastroduodenoscopy [(EGD), a procedure used to look at the esophagus, stomach and part of the small intestine] and colonoscopy,” says Calderwood.

The sharpest drop in screening volumes happened immediately after the pandemic reached the U.S. in March of 2020. Study results of more than 450 practice sites with over 3,500 endoscopists showed that the average monthly volume of colonoscopies dropped by 38.5 percent and EGD by 33.4 percent. There was some regional variation, with the greatest decline in the performance of procedures in the northeast and the least decline in the south. The study also showed indications or reasons for needing endoscopy procedure shifting away from routine prevention to diagnostic, as well as an increase in performance in the hospital setting. Most notably and concerning, 30 percent fewer colorectal cancer diagnoses were found from March to September 2020 compared to expected based on the prior year. 

While endoscopy screening volumes have bounced back somewhat, they haven’t resumed pre-pandemic levels. “The question now is, how do we help those who need screening who have been delayed get their screening, while also making sure people with symptoms get timely care, all within a system with finite capacity?” asks Calderwood.

What does this mean?

A dramatic reduction in colonoscopy at the onset of the pandemic was not unexpected by Calderwood’s team, nor was the shift to sicker patients being cared for in hospitals that continued performing procedures that were urgent. The drop in procedures involving trainees was also anticipated. “For a teaching hospital like Dartmouth-Hitchcock, we didn’t want to put our medical students, residents and fellows at risk, nor did we want to use extra masks and other personal protective equipment or PPE unnecessarily by having additional people in the exam room,” says Calderwood. “There were so many unknowns that for months, trainees didn’t perform any procedures even though the procedures are part of their regular education.”  

What did surprise Calderwood was the short time period in which the team could already see a change in colorectal cancer diagnoses. “Around April 2020, our data showed a dramatic drop in colorectal cancer diagnoses. We have no reason to think there would be factors accounting for that drop beside the parallel drop in screening exams being performed. There was not an actual change in the number of cancers. We just weren’t detecting them,” says Calderwood, who does worry about when these patients will be diagnosed and whether the stage of their cancer and outcomes will be different due to the delay. “If we were able to make up for lost time and find all of those cancers that were not diagnosed, the rate of diagnoses in our study should go way up.  But our data isn’t showing that. This tells us there are people with cancer who have not been diagnosed and are not getting the care they need.” 

Why screening volumes dropped off

Not including patient hesitancy, there were several obstacles limiting the ability of health centers to perform endoscopy.

The first was the sudden PPE shortage. “We didn’t even have enough masks at the time,” notes Calderwood. Centers for Medicare & Medicaid Services issued guidance that all non-urgent surgeries and medical procedures, such as screening colonoscopy, be delayed. Many staff were diverted from their regular duties to handle COVID-related triaging. In the harder-hit parts of the country, these diversions included physicians who normally perform endoscopy but suddenly had to dedicate their time entirely to caring for COVID-19 patients. Stay-at-home orders not only kept patients away but created staffing issues out of caution as knowledge of virus transmission increased. “I do think patient hesitancy to enter medical facilities may have contributed to the lower procedures, especially in the fall of 2020, but our study can’t parse out the exact impact of the different factors,” says Calderwood.

Next steps

Data collection studies are a beginning step in the COVID-19 recovery phase. “If we can understand the magnitude of reduction in screening procedures, we can better strategize how our systems might make up for missed care when we finally come out of the pandemic,” says Calderwood, whose team plans to look at longer-term data and consequences of reduced screening volumes. “We need to think broadly to put systems in place to help our patients catch up on missed care, making sure care is distributed in an equitable way.”

Calderwood encourages the medical community to be aware of these issues, increase outreach and add and maintain systems that offer more options for care, such as telehealth visits and at-home screening tests where possible.

She encourages patients and members of the community to understand that there are several colorectal cancer screening options, some of which can be done at home if someone can’t come to the hospital. For those who remain hesitant, “please get vaccinated and come for care. There are many things besides COVID-19 that can affect your health and quality of life. Now that we understand COVID-19 transmission and have safety precautions in place, it's very safe to come to the hospital for your regular and preventative care.”

To learn more about colorectal cancer screening options and schedule a routine screening, please talk with your primary care provider or call D-H Gastroenterology at (603) 650-5030.

A link to Dr. Calderwood's published study is available here.