Camera Capsule Endoscopy in the Routine Diagnostic Pathway for Colorectal Diseases

Overview

The Department of Surgery at Odense University Hospital (OUH) carries out approximately 10,000 colonoscopies each year, and this number is continuously increasing. Since 2014, the screening for colorectal cancer (CRC) has resulted in a significant increase in the colonoscopy workload. Conventional optical colonoscopy (OC) is a hospital-based procedure that can require sedation or analgesics and is often considered uncomfortable, intimidating, or even painful. The diagnostic yield of OC can be as low as 3-5% in some patient groups, which means that an endoscopist may need to perform 20 to 30 colonoscopies to identify one case requiring treatment. Physical or cultural barriers can also deter patients from attending appointments, leading to missed cancers or precancerous lesions. To address these challenges, an alternative pathway is needed to reduce the colonoscopy burden on the healthcare system while ensuring fewer findings are missed. One solution is to use Colon Capsule Endoscopy (CCE) as a triage tool. This procedure can be performed in outpatient healthcare centers and requires less equipment than an OC. However, CCE offers no therapeutic capability, and individuals with clinically significant findings will still require an OC. A low reinvestigation rate (\<25%-30%) is desirable for patient preference and the economy. Therefore, DanCap will introduce a new pathway that relies on CCE for routine colorectal examinations of symptomatic patients who are expected to have a low rate of positive findings and, consequently, a low reinvestigation rate, and asses the cost of this new pathway.

As the sensitivity of OC and CCE is constantly increasing and progressively smaller-size pathologies are detected, the association between detected lesions and patients' short- and long-term outcomes is becoming more uncertain. In some cases, such as with the resection of diminutive polyps, the number needed to treat to save one person (approx. 8.000) is very close to the number needed to cause one procedure-related death (10.000). Therefore, there is an increasing need to filter OC candidates and define a realistic threshold for treating or ignoring lesions. The DanCap study fulfils this need by introducing a renewed approach to the diagnostic pathways using CCE. This approach offers out-of-hospital, accurate bowel diagnostics that allow for the decongestion of endoscopic services, as seen in the UK. It has an upscaling potential for national and international redesign of bowel diagnostics. Several clinical trials have demonstrated the strengths and weaknesses of CCE as compared to OC. The Scottish and English Services have shown the feasibility of routine use of CCE and the CCE-based services confirmed already known data with real-world equivalents regarding CCE's safety and high diagnostic quality. However, there are remaining concerns, primarily due to the high (45-60%) re-investigation rate, which makes the patient experience and cost-efficiency of CCE-based services inferior to that of the conventional OC counterpart. Based on these recent findings, setting up a routine diagnostic pathway for further evaluation of CCE in the clinical routine of patients with a low frequency of positive findings, including cost-efficiency assessment, is highly relevant. Here, introducing methods to predict a patient's findings may be extra relevant in the future. Currently, studies suggest that the use of faecal haemoglobin concentration or the microbiome composition may be useful biomarkers for colorectal cancer or precursor lesions. The predictive potential of these biomarkers in a diagnostic pathway has yet to be sufficiently tested, and more evidence is needed before clinical application is possible. Our study aims to investigate the DanCap pathway as a viable solution for CCE-based diagnostics in symptomatic patients, considered to have a high need for endoscopic evaluation due to the symptoms compatible with neoplastic disease, as referred from general practice (GP). This approach is expected to be cost-effective and maintain high clinical quality while relieving the burden on endoscopy wards in a Danish setting. The study will provide data for pathway cost analysis of the CCE-based pathway compared to the traditional colonoscopy pathway based on a realistic medicine outcomes assessment. The secondary aims are to: 1. Compare the polyp detection rate (PDR) and CRC detection rates in both groups 2. Investigate the role of FIT-testing and microbiome analyses in CCE-based diagnostics for predictive purposes