Stool-based DNA testing versus colon capsule endoscopy for colorectal cancer screening during the COVID-19 pandemic: a response to 'Colon capsule endoscopy: an innovative method for detecting colorectal pathology during the COVID-19 pandemic?'

Dear Editor,

We applaud the ingenuity of MacLeod et al. [1] for their insight into the potential of colon capsule endoscopy (CCE) as an alternative modality for colon cancer screening and diagnosis. We have similarly been committed to approaching this dilemma in the context of scarce resources as well as risks inherent to the COVID‐19 pandemic [2]. However, we did not include CCE in our discussion and commend the authors for their ingenuity.

Noninvasive screening tests for colorectal cancer (CRC) are projected to be necessary for the appropriate triage of delayed screening colonoscopy procedures in the setting of the COVID‐19 pandemic and are amplified in the setting of a resurgence in June 2020.

The current literature, including systematic reviews and meta‐analyses, supports CCE as a potential non‐invasive technique for CRC screening. A prospective clinical trial by Rex et al. [3] showed that, in a screening population at average risk, CCE identified patients with one or more conventional adenomas 6 mm or larger with 88% sensitivity and 82% specificity.

The findings from the DeeP‐C cross‐sectional study compared multitarget stool DNA faecal immunological testing with colonoscopy as the reference standard [4]. According to Imperiale et al. [4], who used multitarget stool DNA tests, the sensitivity for detecting CRC was 92.3% and the specificity 86.6%, with the sensitivity for detecting advanced adenomas being 42.4% and for detection of polyps with high‐grade dysplasia 69.2%.

There are significant limitations to CCE, including associated complications that may occur [5]. Prior abdominal surgery, suspected bowel obstruction, possibly from a colonic mass, or stricture lesions, especially associated with inflammatory bowel disease, would not allow CCE to be a viable option due to the risk of capsule retention, obstruction and possible bowel perforation [5].

Another limitation to CCE in the setting of the COVID‐19 pandemic would be the need for experienced and trained physicians to provide accurate and timely results. Following from this is the cost: the average cost of CCE is estimated at $950 or €700 [5] compared with the average cost of Cologuard™ at approximately $600. Multitarget DNA stool tests are safer, more cost‐effective, more readily accessible and easier for patients to use than CCE. These aspects of multitarget DNA stool tests make such tests more efficacious as an alternative screening modality for CRC in the setting of the COVID‐19 pandemic.

Due to the cost, risk and other alternatives, CCE should not be considered as an alternative to screening colonoscopy during the current pandemic. We suggest that it is only considered as a surrogate for diagnostic colonoscopy, and only in the setting of a positive multitarget DNA stool test and capsule patency studies, if conventional colonoscopy is prohibitive.

This is a very interesting opportunity to potentially improve the algorithm for high‐risk patients and screening for colon and rectal cancer. To summarize:

Colonoscopy is the gold standard when appropriate;

DNA‐based molecular stool studies should be used when the risk/resources are prohibitive for colonoscopy;

Diagnostic CCE should be considered for patients who are positive on stool‐based molecular screening and are unable to undergo conventional diagnostic colonoscopy.

Funding

The authors of this correspondence letter did not receive any funding for the drafting of this manuscript.

Conflicts of interest

The authors of this correspondence letter confirm that there are no conflicts of interest with regards to the information included in the submitted manuscript.

Ethics approval statement

The authors of this correspondence letter confirm and agree with the rigorous ethical standards associated with scientific published literature.

Patient consent statement

No patients were included in this correspondence letter, and thus, patient consent is not required for this correspondence letter to be published.