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.

Detailed Description

Study Overview This is a pragmatic, prospective, observational study designed to compare colon capsule endoscopy (CCE) with conventional colonoscopy in individuals with genetically confirmed Lynch syndrome. The study is conducted within an established colorectal cancer surveillance program and reflects routine clinical practice.

Study Objectives The primary objective of the study is to evaluate the diagnostic performance and safety of colon capsule endoscopy when used as a first-line surveillance examination in patients with genetically confirmed Lynch syndrome. Secondary objectives include assessment of patient-reported experience, acceptability, and preference for colon capsule endoscopy compared with conventional colonoscopy, assuming equivalent diagnostic performance.

Study Design and Procedures Participants undergo both colon capsule endoscopy and conventional colonoscopy using a paired, same-day, blinded design. Colon capsule endoscopy is performed using a standardized bowel preparation protocol. The capsule examination is interpreted by an experienced specialist physician.

Conventional colonoscopy, representing standard of care, is scheduled after confirmed capsule excretion on the same day without additional bowel preparation, or, if necessary, on the morning following the capsule examination. Sedation is offered according to local clinical practice. The endoscopist performing the colonoscopy is blinded to the capsule endoscopy findings.

Both examinations are evaluated, documented, and reported using predefined and standardized assessment criteria.

Blinding and Clinical Decision-Making Results from both examinations are communicated to the participant's responsible physician, who is not blinded and determines subsequent diagnostic evaluation, treatment, and continued surveillance in accordance with current clinical guidelines.

Patient-Reported Outcomes Following completion of both procedures, participants complete a structured questionnaire assessing procedural experience, perceived burden, and acceptability of colon capsule endoscopy and conventional colonoscopy. Participants are also asked to indicate their preferred examination modality if diagnostic performance is considered comparable.

Study Timeline Enrolling patients is anticipated from february 2026, with anticipated completion in December 2028.

Scientific Rationale Individuals with Lynch syndrome require lifelong colorectal surveillance beginning at a young age. Conventional colonoscopy, while effective, is invasive and resource intensive, which may affect patient adherence and healthcare capacity. Colon capsule endoscopy is a minimally invasive imaging modality that enables endoluminal visualization of the colon without the need for sedation or endoscope insertion. Evaluation of the diagnostic performance, safety, and patient acceptability of colon capsule endoscopy in this high-risk population may inform future surveillance strategies and optimize resource utilization.

Inclusion Criteria:

• Genetically confirmed Lynch syndrome with a planned surveillance colonoscopy according to guideline-based recommendations
• Age 18-60 years
• Written informed consent obtained

Exclusion Criteria:

• Need for an translator
• Known history of gastroparesis or intestinal pseudo-obstruction
• Known or suspected stricture or stenosis of the gastrointestinal tract
• Previous small bowel or colonic resection
• Dysphagia or swallowing difficulties
• Severe debilitating disease
• Allergy or contraindication to any medications or products used in the study
• Pregnancy or breastfeeding

The study population consists of adults aged 18-60 years with genetically confirmed Lynch syndrome who are referred for guideline-based surveillance colonoscopy at Skåne University Hospital, Malmö. Eligible participants are identified by referring physicians at the endoscopy unit or gastroenterology outpatient clinic.

Consecutive patients who meet the inclusion criteria and have no contraindications to colon capsule endoscopy or study participation are invited to enroll. Participants undergo both non-invasive colon capsule endoscopy and conventional colonoscopy according to the study protocol.

Written informed consent is obtained by a study physician prior to any study-related procedures and documented in the medical record. Participation is voluntary, and participants may withdraw at any time without impact on future medical care.

A total of 80 consecutive patients will be enrolled. The study evaluates the diagnostic performance and safety of colon capsule endoscopy as a first-line

Individual participant data will not be shared with other researchers. The study includes a limited number of participants with a rare hereditary condition, and the dataset contains sensitive clinical and genetic information. Data sharing outside the study group is therefore not planned, in accordance with the approved ethics application, informed consent, and applicable data protection regulations.