Boston University, Boston Medical Center Boston, MA, United States
Heidi Ahmed, MD1, James Connolly, MD1, Enoch Chung, BS2, Howard Cabral, PhD3, Arpan Mohanty, MBBS1 1Boston University, Boston Medical Center, Boston, MA; 2Boston University, Boston, MA; 3Boston University School of Public Health, Boston, MA
Introduction: During the COVID-19 pandemic, outpatient colonoscopies throughout the US were postponed, creating a significant backlog of procedures. We estimated the number of missed high-risk adenomas and colorectal cancers in 2020 at an urban, tertiary-care, safety-net teaching hospital in Boston, Massachusetts.
Methods: This observational study evaluated the number of high-risk adenomas (defined as ≥3 adenomas, adenoma ≥10 mm in size, adenoma with tubulovillous or villous histological features, or adenoma with high-grade dysplasia) and colorectal cancers diagnosed by outpatient colonoscopy from January 2020 to November 2020, and compared it with those diagnosed from January 2017 to December 2019. Patients with a personal history of colorectal cancer or a colonoscopy indication of inflammatory bowel disease, therapeutic procedure (other than removal of large polyp), or diarrhea were excluded (10% of all colonoscopies). A Poisson regression model using colonoscopy data from 2017 to 2019--adjusted for age, sex, race/ethnicity and indication--was used to predict expected high-risk adenomas and colorectal cancers per month in 2020. Predicted values were compared to actual values to estimate missed diagnoses.
Results: A total of 6597, 7136, and 6816 colonoscopies were performed in 2017, 2018 and 2019, respectively. There were 40% fewer colonoscopies performed in January to November 2020 (n = 3704) compared to the same period in 2019. In January to November 2020, 505 high-risk adenomas (Figure 1a) and 21 colorectal cancers (Figure 1b) were diagnosed. We estimate that 284 (36%) high-risk adenomas and 9 (30%) colorectal cancers were missed during this period. The rate of colorectal cancer detection was 6 per 1000 cases performed in 2017 to 2019. Assuming similar patient characteristics and indications, 1349 additional colonoscopies will be needed to diagnose 9 missed colorectal cancers.
Discussion: This study provides one of the first real world estimates of missed high-risk adenomas and colorectal cancers due to the cancellation of outpatient colonoscopies during the COVID-19 pandemic. The results have implications on planning strategies to schedule elective colonoscopies to increase the yield of detection of these high-risk lesions.
Figure: Figure 1a. Actual versus Predicted High-Risk Adenomas. Figure 1b. Actual versus Predicted Colorectal Cancers. Solid line—actual values; dashed line—predicted values; shaded area—95% confidence interval of predicted values
Heidi Ahmed indicated no relevant financial relationships.
James Connolly indicated no relevant financial relationships.
Enoch Chung indicated no relevant financial relationships.
Howard Cabral indicated no relevant financial relationships.
Arpan Mohanty indicated no relevant financial relationships.
Heidi Ahmed, MD1, James Connolly, MD1, Enoch Chung, BS2, Howard Cabral, PhD3, Arpan Mohanty, MBBS1. P1304 - Missed High-Risk Adenomas and Colorectal Cancers Due to COVID-19 Pandemic at an Urban U.S. Tertiary Care Center in 2020, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.