Non-Invasive Screening for Colorectal Cancer During COVID-19 Pandemic

Interior treatment room with digital endoscope for diagnosis of hollow organs, colonoscopy, gastroscopy in multidisciplinary Clinic.
With elective endoscopies halted during the COVID-19 pandemic, researchers analyzed the impact of this cessation on rates of colorectal cancer screening.

Stool-based screening methods for colorectal cancers helped screening rates recover to pre-pandemic levels after a drastic decline in rates of invasive screening methods due to COVID-19 public health measures. The results from this investigation were published in Gastroenterology.

In 2020, the United States Surgeon General advised hospitals and ambulatory surgical centers to postpone nonurgent surgeries and medical procedures, including elective endoscopies. Stool-based colorectal cancer screening modalities were encouraged instead. Electronic health records from a single health system in southern California were retrospectively analyzed to assess the impact of these recommendations.

During the pre-pandemic period of January 29, 2020 to March 17, 2020, an average of 382.4±54.8 screening tests were performed each week. This included 222.6±33.0 colonoscopies and 154.0±25.2 fecal immunochemical tests per week. During the period when endoscopy was halted, March 18, 2020 to May 4, 2020, the total average dropped to 74.3±47.1 procedures per week (P <.01), with the steepest decline being in colonoscopy, with only 11.4±11.1 performed per week (P <.01). Fecal immunochemical testing also dropped significantly to 60.6±52.7 tests per week (P <.02) and then recovered slightly during the last weeks of the cessation period.

When elective endoscopy was resumed, overall screening test utilization returned to pre-pandemic rates of 346.8±93.4 procedures per week (P =.53). However, colonoscopy rates were lower than pre-pandemic rates at 174.2±47.1 procedures performed each week (P <.02), while the use of several non-invasive methods equaled or exceeded pre-pandemic rates. This included fecal immunochemical testing increasing from 154.0±25.2 to 162.0±55.2 tests per week (P =.54) and stool DNA from 0.0 to 6.0±3.2 tests per week (P <.01).

The rates of colonoscopy after a negative fecal immunochemical test were similar during the study period and an equivalent period 1-year prior to the pandemic, suggesting the fecal testing was not being used in addition to colonoscopy but as an alternative while access was limited.

Study limitations included the quasi-experimental nature and the absence of clinical outcomes by screening method. A study strength is the generalizability of the findings.

Investigators concluded, “this work highlights the potential of stool-based CRC [colorectal cancer] screening modalities as a useful alternative to colonoscopy in the midst of the ongoing COVID-19 pandemic.”


Myint A, Roh L, Yang L, Connolly L, Esrailian E, May FP. Non-invasive colorectal cancer screening tests help close screening gaps during COVID-19 pandemic. Gastroenterol. Published online April 15, 2021. doi: 10.1053/j.gastro.2021.04.026

This article originally appeared on Gastroenterology Advisor