N38: Yield Of Lynch Syndrome Surveillance For Individual MMR Genes

A. Goverde1, A. Wagner1, E. Viskil1, M. J. Bruno2, R. M. W. Hofstra1, M. C. W. Spaander2

1 – Department of Clinical Genetics. Erasmus MC, University Medical Center, Rotterdam, The Netherlands. 2 – Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.


Aim: To assess the yield of Lynch syndrome (LS) surveillance for MLH1, MSH2, MSH6 and PMS2 mutation carriers.

Method: Data on colonoscopy surveillance was collected for all LS mutation carriers in our center. We compared the development of adenomas and CRC between the different gene mutation carrier groups.

Results: Colonoscopy data was available for 264/314 (84%) patients; 55 MLH1, 44 MSH2, 143 MSH6 and 22 PMS2 mutation carriers. Median age was 44 years (IQR 35-56 years) and median follow-up time 6 years (IQR 2-10 years). At first colonoscopy CRC was found in eight patients and during 916 follow-up colonoscopies in nine patients. No CRC was found in MSH6 or PMS2 mutation carriers. There were no significant differences in the number of colonoscopies with adenomas or advanced adenomas between the different gene mutation carrier groups. In MSH6 mutation carriers advanced neoplasia (advanced adenoma or colorectal carcinoma) was found after a longer follow-up time than in the other mutation carrier groups.

Conclusion: Since no CRC was found during follow-up in MSH6 mutation carriers and advanced neoplasia was found in shorter follow-up time in MLH1 and MSH2 mutation carriers, the colonoscopy interval in MSH6 mutation carriers might be less stringent than for MLH1 and MSH2 mutation carriers.