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

Abstract

We read with great interest the multicentre UK study evaluating the diagnostic accuracy of colon capsule endoscopy (CCE) compared to colonoscopy and computed tomography colonography [1]. While the study provided valuable real-world data, certain interpretations of reinvestigation rates, in particular, raise some concerns.

There is an inherent risk of overestimation of CCE's performance as a ‘filter test’ when CCE is said to spare 86% from an urgent test, and yet a significant proportion still required follow-up due to poor preparation. The reinvestigation rate following CCE is rather high—nearly half of patients requiring colonoscopy or flexible sigmoidoscopy, often due to pathology identified, had incomplete studies or inadequate bowel preparation. This raises concerns about cost-effectiveness if duplicate investigations are required.

However, these findings should not be viewed in isolation, as multiple factors may contribute to the reinvestigation rate.

Polyp overdiagnosis: CCE identified more polyps than colonoscopy, particularly in the 6–9 mm range, underscoring its high sensitivity. However, it also raises concerns about potential overdiagnosis, possibly due to double-counting [2], polyp mismatching [2-4] and polyp size overestimation [4].

Polyp characterisation: Since CCE and colonoscopy use different visualisation techniques (water and gaseous distension), recent advances in polyp characterisation [5] and localisation [6]—potentially aided by machine learning algorithms [7]—could improve specificity and reduce excessive downstream colonoscopies.

Clinician confidence and learning curve: A crucial factor contributing to the high reinvestigation rate is clinician confidence and familiarity with CCE interpretation. As a newer diagnostic tool, CCE lacks the provider experience and trust of traditional colonoscopy [8], leading many clinicians to recommend follow-up investigations even when CCE findings are technically complete. This learning curve may also contribute to discrepancies in diagnostic yield, particularly for small polyps or ambiguous pathology. Structured training programmes and standardised reporting criteria [5] could enhance confidence and reduce unnecessary follow-ups.

Patient selection and clinical pathways: CCE was introduced to ease colonoscopy demand by prioritising high-risk cases and optimising resources. However, its effectiveness hinges on precise patient selection—probably benefiting lower-risk cohorts where, in this study, > 45% had a faecal immunochemical test of 60–100 μg/g. Clear selection criteria and refined clinical pathways are essential to maximise utility and minimise unnecessary further investigations.

Given these challenges, further evidence and analysis are warranted before drawing firm conclusions about CCE's clinical value. A broader meta-analysis incorporating emerging data would help to clarify true completion rates, sustainability and long-term healthcare efficiency. Furthermore, CCE's potential for home-based diagnostics presents an opportunity to improve accessibility and efficiency, which should not be overlooked [9, 10].

Policy decisions should take a balanced approach, weighing reinvestigation rates and costs alongside CCE's benefits in patient acceptability, diagnostic access (reducing health disparities) and resource optimisation. A holistic evaluation is crucial to ensure future recommendations reflect the full spectrum of evidence.

Ian Io Lei: writing – original draft, writing – review and editing. Ramesh P. Arasaradnam: conceptualization, writing – review and editing, validation, supervision. Anastasios Koulaouzidis: writing – original draft, writing – review and editing, validation, supervision.

This article is linked to Turvill et al. paper. To view this article, visit, https://doi/10.1111/apt.70046 and https://doi.org/10.1111/apt.70105.