Letter: Balancing Cost and Consequence of Colon Capsule Endoscopy in Colorectal Cancer Pathways—Finding the Sweet Spot. Authors' Reply

Abstract

The authors of the large English colon capsule endoscopy (CCE) diagnostic accuracy study are grateful to Dr. Lei et al. for their informed and thoughtful observations [1, 2]. We think that there are two important and related observations of our own to make in response.

First, on an ‘intention to investigate’ basis, rather than in complete and adequately prepared CCE, more polyps were detected by CCE than colonoscopy. This meant that an informed management plan could be made for many patients even when CCE was incomplete or inadequately prepared. Second, as you infer, CCE was introduced to mitigate the impact of the Covid-19 pandemic on colorectal cancer diagnosis. That is, its purpose was primarily to inform risk rather than prevent onward investigation, as one might plan for in the future.

We very much agree that multiple, mitigatable factors, not yet fully defined, may contribute to the onward investigation rate and so inform how best CCE should complement a future colorectal diagnostics pathway. Beyond patient selection, touched on above, all of the factors outlined are absolutely pertinent. Our own view about polyp overdiagnosis is uncertain. Double counting seems unlikely since polyp detection was recorded on both a per patient and per polyp basis. The high false positivity of polyps ≥ 10 mm in those who had matched investigations, both of which were complete and adequately prepared, suggests that the reference standard may need to be revisited.

We believe other factors are also important, such as shared decision making, patient choice, and the purpose of CCE in a clinical setting. We very much agree that such should help generate a ‘balanced approach’ for future recommendations. Our study importantly allows us to move beyond the safety and accuracy across a broad clinical setting and into that exciting new space where we can optimise.