N62: Genetic And Clinical Features In Russian Patients With Lynch Syndrome

D. Y. Pikunov, A. S. Tsukanov, S. I. Achkasov, V. P. Shubin, D. A. Semenov

State Scientific Centre of Coloproctology


Aim: Up to 3% of all colorectal cancers are connected with Lynch syndrome (LS), which is caused by mutations in mismatch repair (MMR) genes. According to the literature the main manifestations of LS are tumors of right colon, endometrium, ovary, kidhey and ureter, stomach ets. at the age of <45.

Method: Between 2012 and 2017 ninety seven patients with primary tumors at the age of <45y.o. and/or with familial history were included in the study. All the tumors were analyzed for microsatellite instability (MSI). In patients with MSI the genes of MMR were examined.

Results: LS was diagnosed in thirty three (34%) out of 97 patients. Twenty of them (60%) had MLH1-gene mutation, 11 (34%) had MSH2-gene mutation, 2 (6%) – MSH6-gene mutation. The median age of primary tumor appearance in patients with LS was 38±7y.o. The primary tumor site was colorectum in 24 (73%) patients, uterus – in 8 (24%) patients, thyroid – in 1 (3%). Among the patients with colorectal cancer right colon lesions were registered in 5 (24%) cases and left colon – in 19 (76%).

Conclusion: In contrast to European patients, Russian patients with LS have MLH1-gene mutation in 60% cases, early-age appearance of colorectal cancer and preferable left-side lesions.