COVID-19’s impact on colorectal cancer screening

Audrey H. Calderwood, MD, MS

Colorectal cancer screenings—often done in a healthcare setting using endoscopic procedures—declined significantly after the COVID-19 pandemic began. Researchers at Dartmouth Cancer Center assessed the impact of COVID-19 on endoscopy procedures at practices across the U.S. 

Led by Audrey H. Calderwood, MD, MS, director of Dartmouth-Hitchcock’s (D-H's) Comprehensive Gastroenterology Center, researchers analyzed data on endoscopy procedures recorded in the GI Quality Improvement Consortium Registry.

“We compared data collected during the pandemic, March to September of 2020, to data collected before the pandemic, January 2019 to February 2020,” Calderwood said. “We 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.”

The sharpest drop occurred in March 2020, just after the pandemic reached the U.S. Through September 2020, the average monthly volume of colonoscopies dropped by 38.5 percent; the volume of EGD procedures fell by 33.4 percent. Results were based on more than 3,500 endoscopists at more than 450 sites.

Especially concerning: There were 30% fewer colorectal cancer diagnoses found from March to September 2020 compared to the prior year. 

While endoscopy screening volumes have bounced back somewhat, they haven’t resumed pre-pandemic levels. “The challenge now,” Calderwood said, “is how to help those who needed screening and were delayed in getting one, while also making sure people with symptoms get timely care.”

Working past “unknowns”

For Calderwood’s team, the dramatic reduction in colonoscopy procedures at the onset of the pandemic was not unexpected—nor was the shift to sicker patients being cared for in hospitals that continued performing urgent procedures. The drop in procedures involving trainees was also anticipated.

“For a teaching hospital like Dartmouth Hitchcock Medical Center, 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,” Calderwood said. “There were so many unknowns that for months, trainees didn’t perform any procedures even though they are part of their regular education.”  

Not getting needed care

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,” she said. “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.”

“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,” she explained. “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 volume decreased

Not including patient hesitancy, there were several obstacles limiting the ability of health centers to perform endoscopy. The first was a sudden PPE shortage. “We didn’t even have enough masks at the time,” Calderwood said.

Another obstacle: The Centers for Medicare & Medicaid Services issued guidance that all non-urgent surgeries and medical procedures, including screening colonoscopies, be delayed. Furthermore, many staff were diverted from their regular duties to handle COVID-19-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 kept patients away and created staffing issues out of caution. “I do think patient hesitancy to enter medical facilities contributed to the lower number of procedures, but our study can’t analyze the exact impact of various factors,” Calderwood said.

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,” Calderwood said. “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. She also hopes to see increased outreach and add or maintain systems that offer more options, such as Telehealth visits and at-home screening tests are examples.

She encourages patients and other members of the community to understand that there are several colorectal cancer screening options, some of which can be done at home. “For those who remain hesitant,” she added, “please get vaccinated and come for care. There are things besides COVID-19 that can affect your health. Now that we understand COVID-19 transmission and have safety precautions in place, it's safe to come to the hospital for regular care.”