The quality of colonoscopy surveillance for Lynch syndrome in Finland

Jutta Lappalainen1, Darja Holmström2, Anna Lepistö3, Juha Saarnio1, Jukka-Pekka Mecklin4,5, Toni Seppälä3,6

1University of Oulu, Oulu, Finland. 2University of Helsinki, Helsinki, Finland. 3Helsinki University Hospital, Helsinki, Finland. 4Jyväskylä University, Jyväskylä, Finland. 5Central Finland Central Hospital, Jyväskylä, Finland. 6Johns Hopkins, Baltimore, USA



Lifetime cumulative incidence of colorectal cancer (CRC) is high in path_MMR carriers despite ongoing colonoscopy surveillance. International registry studies based on national Lynch syndrome (LS) registries have been criticized for not reporting colonoscopy quality adequately.



Prospective follow-up data from the Lynch Syndrome Registry of Finland (LSRFi) data were combined with a retrospective assessment of the colonoscopy reports from Helsinki University Hospital electronic patients record in 2004–2019.



366 path_MMR carriers participated in surveillance, undergoing total of 1564 examinations (mean 4.3 per patient, range 1–10) at a single unit. After the inclusion round of first colonoscopies, 336 patients underwent at least one subsequent examination. At second colonoscopy, 250 carriers had not undergone colorectal surgery and 86 had had previous bowel resections.

In 11.8% of examinations, bowel preparation was suboptimal (Boston Bowel Preparation Scale 2) on either right or left side of the colon. In 25 (1.6%) examinations, BBPS was 0–1. All large bowel length was not seen in 21 (1.3%) of endoscopies. Ceacal intubation rate was 98.7% for those without previous colorectal surgery. Adenoma detection rate was 18.6% across all examinations.

During surveillance, 23 CRCs were detected. 19 cancers were detected after 1017 optimal quality colonoscopies and 4 after 158 compromised quality (BBPS<3 or non-complete examination; p=0.58). Adenoma was removed from the same bowel segment in 2/23 at the previous colonoscopy.



The vast majority of CRCs are detected after good quality surveillance colonoscopies. Neoplasias of the same bowel segment at the previous examination are rare.