Surveillance of the small-bowel by capsule endoscopy in Lynch syndrome - A systematic review with meta-analysis

Abstract

Background & aims: The role of small-bowel (SB) cancer surveillance by capsule endoscopy (CE) in Lynch syndrome (LS) patients has been investigated in recent years, with contradicting results. This meta-analysis evaluates the diagnostic yield (DY) of CE as a screening tool in asymptomatic LS patients.

Methods: A systematic literature search was performed for all studies reporting the results of SB cancer screening in patients with LS. The primary outcome was the evaluation of the DY of CE in this setting for consecutive screening rounds.

Results: Five studies comprising 428 patients and CE 677 procedures were included for data extraction and statistical analysis. The estimated pooled DY for CE-identified pathological findings was 8% in the first screening round and 6% in the second. Limiting the analysis to histologically-confirmed pathological findings, the pooled DY of second-round screening dropped to 0%. The included studies showed a significantly different prevalence of pathogenic variants in mismatch repair (path_MMR) genes, which underlie different cumulative incidences of extracolonic cancers.

Conclusions: SB surveillance by CE with a 2-year interval in asymptomatic LS individuals does not appear to be an effective screening strategy. Confirmatory prospective studies in this context are needed, considering the different cumulative incidence of SB tumors according to underlying path_MMR defects.

Keywords: Capsule endoscopy; HNPCC; Lynch syndrome; Screening; Small bowel.