Evaluation of Capsule Colonoscopy in Patients With Lynch Syndrome

Lynch syndrome is the most common hereditary cancer syndrome and is caused by pathogenic variants in DNA mismatch repair genes, resulting in a markedly increased lifetime risk of colorectal cancer. The estimated lifetime risk of colorectal cancer varies by the affected gene and is approximately 54-74% in men and 30-52% in women with Lynch syndrome. Colorectal cancer in this population is typically diagnosed at a younger age than in the general population. Current national guidelines recommend colonoscopic surveillance every one to two years beginning at 20-25 years of age to reduce colorectal cancer risk. However, individualized modification of surveillance strategies is under active consideration based on factors such as the specific mutated gene, family history of cancer, smoking status, prior malignancies, and age at surveillance initiation.

Conventional colonoscopy, the current standard method for colorectal evaluation, may cause substantial discomfort or anxiety, leading some patients to decline participation. Colonoscopy is also resource intensive, and procedural capacity is limited. Previously reported limitations in colonoscopy resources and quality in Sweden highlight the need to evaluate alternative surveillance and screening approaches.

Colon capsule endoscopy (CCE) has been available for clinical use since 2006 as a non-invasive alternative to colonoscopy, enabling endoscopic visualization of the entire colon. The system consists of a single-use, swallowable capsule containing miniature cameras that capture images as the capsule progresses through the gastrointestinal tract via natural peristalsis. Images are transmitted wirelessly to a portable data recorder worn by the patient and subsequently reviewed using dedicated software.

CCE offers several advantages compared with conventional colonoscopy and CT colonography, including no requirement for sedation, endoscope insertion, gas insufflation, or ionizing radiation. The examination and image acquisition can be performed outside the hospital setting. This patient-centered approach has the potential to improve adherence to repeated examinations and long-term surveillance programs, which is particularly important for individuals with hereditary colorectal cancer syndromes. CCE may also reduce demands on healthcare resources.

International guidelines indicate that the mucosal diagnostic performance of CCE is comparable to that of standard colonoscopy and that the method is appropriate for screening purposes. Adequate bowel preparation is required for both colonoscopy and CCE. Unlike conventional colonoscopy, bowel cleansing cannot be optimized during CCE, and the procedure is limited by capsule battery life, typically 10-12 hours. To maintain bowel cleanliness and facilitate capsule transit, patients administer laxative and prokinetic agents at predefined time points during the examination.

The primary objective of this study is to evaluate the diagnostic performance and safety of colon capsule endoscopy as a first-line surveillance modality in patients with Lynch syndrome and to assess patient experience and acceptance of CCE compared with conventional colonoscopy.