%0 Journal Article
%T Colorectal cancer and advanced adenoma characteristics according to causative mismatch repair gene variant in Japanese colorectal surveillance for Lynch syndrome.
%A Chino A
%A Tanakaya K
%A Nakajima T
%A Akagi K
%A Takao A
%A Yamada M
%A Ishida H
%A Komori K
%A Sasaki K
%A Miguchi M
%A Hirata K
%A Sudo T
%A Miyakura Y
%A Ishikawa T
%A Yamaguchi T
%A Tomita N
%A Ajioka Y
%J J Gastroenterol
%V 59
%N 8
%D 2024 Aug 21
%M 38902413
%F 6.772
%R 10.1007/s00535-024-02128-5
%X <B>BACKGROUND: </B>The optimal interval of colonoscopy (CS) surveillance in cases with Lynch syndrome (LS), and stratification according to the causative mismatch repair gene mutation, has received much attention. To verify a feasible and effective CS surveillance strategy, we investigated the colorectal cancer (CRC) incidence at different intervals and the characteristics of precancerous colorectal lesions of LS cases.<BR><B>METHODS: </B>This retrospective multicenter study was conducted in Japan. CRCs and advanced adenomas (AAs) in 316 LS cases with germline pathogenic variants (path_) were analyzed according to the data of 1,756 registered CS.<BR><B>RESULTS: </B>The mean time interval for advanced CRCs (ACs) detected via CS surveillance was 28.7 months (95% confidence interval: 13.8-43.5). The rate of AC detection within (2.1%) and beyond 2 years (8.7%) differed significantly (p = 0.0003). AAs accounted for 43%, 46%, and 41% of lesions < 10 mm in size in the MLH1-, MSH2-, and MSH6-groups, respectively. The lifetime incidence of metachronous CRCs requiring intestinal resection for path_MLH1, path_MSH2, and path_MSH6 cases was 34%, 23%, and 14% in these cases, respectively. The cumulative CRC incidence showed a trend towards a 10-year delay for path_MSH6 cases as compared with that for path_MLH1 and path_MSH2 cases.<BR><B>CONCLUSIONS: </B>In cases with path_MLH1, path_MSH2, and path_MSH6, maintaining an appropriate CS surveillance interval of within 2 years is advisable to detect of the colorectal lesion amenable to endoscopic treatment. path_MSH6 cases could be stratified with path_MLH1 and MSH2 cases in terms of risk of metachronous CRC and age of onset.