Colonoscopies Restricted by Pandemic: Worse CRC Outcomes to Come?

Will Pass

May 27, 2021

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For veterans, changes in colonoscopy screening caused by the COVID-19 pandemic may have increased risks of delayed colorectal cancer (CRC) diagnosis and could lead to worse CRC outcomes, based on data from more than 33,000 patients in the Veterans Health Administration.

After COVID-19 screening policies were implemented, a significantly lower rate of veterans with red-flag signs or symptoms for CRC underwent colonoscopy, lead author Joshua Demb, PhD, a cancer epidemiologist at the University of California, San Diego, reported at the annual Digestive Disease Week® (DDW).

"As a result of the COVID-19 pandemic, the Veterans Health Administration enacted risk mitigation and management strategies in March 2020, including postponement of nearly all colonoscopies," the investigators reported. "Notably, this included veterans with red flag signs or symptoms for CRC, among whom delays in workup could increase risk for later-stage and fatal CRC, if present."

To measure the effects of this policy change, Demb and colleagues performed a cohort study involving 33,804 veterans with red-flag signs or symptoms for CRC, including hematochezia, iron deficiency anemia, or abnormal guaiac fecal occult blood test or fecal immunochemical test (FIT). Veterans were divided into two cohorts based on date of first red flag diagnosis: either before the COVID-19 policy was implemented (April to October 2019; n = 19,472) or after (April to October 2020; n = 14,332), with an intervening 6-month washout period.

Primary outcomes were proportion completing colonoscopy and time to colonoscopy completion. Multivariable logistic regression incorporated a number of demographic and medical covariates, including race/ethnicity, sex, age, number of red-flag signs/symptoms, first red-flag sign/symptom, and others.

Before the COVID-19 policy change, 44% of individuals with red-flag signs or symptoms received a colonoscopy, compared with 32% after the policy was introduced (P < .01). Adjusted models showed that veterans in the COVID policy group were 42% less likely to receive a diagnostic colonoscopy than those in the prepolicy group (odds ratio, 0.58; 95% confidence interval, 0.55-0.61). While these findings showed greater likelihood of receiving a screening before the pandemic, postpolicy colonoscopies were conducted sooner, with a median time to procedure of 41 days, compared with 65 days before the pandemic (P < .01). Similar differences in screening rates between pre- and postpandemic groups were observed across all types of red flag signs and symptoms.

"Lower colonoscopy uptake was observed among individuals with red-flag signs/symptoms for CRC post- versus preimplementation of COVID-19 policies, suggesting increased future risk for delayed CRC diagnosis and adverse CRC outcomes," the investigators concluded.

Prioritization May Be Needed to Overcome Backlog of Colonoscopies

Jill Tinmouth, MD, PhD, lead scientist for ColonCancerCheck, Ontario's organized colorectal cancer screening program, and a gastroenterologist and scientist at Sunnybrook Health Sciences Centre, Toronto, shared similar concerns about delayed diagnoses.

Dr Jill Tinmouth

"We might expect these cancers to present ... at a more advanced stage, and that, as a result, the outcomes from these cancers could be worse," Tinmouth said in an interview.

She also noted the change in colonoscopy timing.

"A particularly interesting finding was that, when a colonoscopy occurred, the time to colonoscopy was shorter during the COVID era than in the pre-COVID era," Tinmouth said. "The authors suggested that this might be as a result of Veterans Health Administration policies implemented as a result of the pandemic that led to prioritization of more urgent procedures."

According to Tinmouth, similar prioritization may be needed to catch up with the backlog of colonoscopies created by pandemic-related policy changes. In a recent study comparing two backlog management techniques, Tinmouth and colleagues concluded that redirecting low-yield colonoscopies to FIT without increasing hospital colonoscopy capacity could reduce time to recovery by more than half.

Even so, screening programs may be facing a long road to recovery.

"Recovery of the colonoscopy backlog is going to be a challenge that will take a while – maybe even years – to resolve," Tinmouth said. "Jurisdictions/institutions that have a strong centralized intake or triage will likely be most successful in resolving the backlog quickly as they will be able to prioritize the most urgent cases, such as persons with an abnormal FIT or with symptoms, and to redirect persons scheduled for a 'low-yield' colonoscopy to have a FIT instead." Ontario defines low-yield colonoscopies as primary screening for average-risk individuals and follow-up colonoscopies for patients with low-risk adenomas at baseline.

When asked about strategies to address future pandemics, Tinmouth said, "I think that two key learnings for me from this [pandemic] are: one, not to let our guard down, and to remain vigilant and prepared – in terms of monitoring, supply chain, equipment, etc.] ... and two to create a nimble and agile health system so that we are able to assess the challenges that the next pandemic brings and address them as quickly as possible." The investigators and Tinmouth reported no conflicts of interest.

This article originally appeared on, part of the Medscape Professional Network.


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