Onkológia 2/2010

Lynch syndrome – novelties in diagnostics and therapy

Lynch syndrome (LS), also known as hereditary non-polyposis colorectal cancer (HNPCC), represents about 3 % of all colorectal cancers and is the most frequent of syndromes with a hereditary predisposition to colorectal carcinoma. Each patient with Lynch syndrome requires genetic counseling, genetic testing of MMR genes („Mismatch repair genes"), a special health care focused on early detection of LS-associated malignancies and a lifetime surveillance. Clinical recognition of the syndrome is carried out through genetic counseling or pathological examination of the histological specimen of the colon tumour. The diagnosis is confirmed by the presence of microsatelite instability in tumour (MSI) and loss of expression of MMR protein determined by immunohistochemistry (IHC). For the optimal distinction between sporadic and hereditary colorectal cancer, new diagnostic screening methods and effective algorithms are explored. Identification of a germline mutation in high-risk families is necessary to allow predictive testing of the family relatives. A program of surveillance and specific treatment procedures is recommended to mutation carriers that is regularly updated by a group of experts for hereditary gastrointestinal tumors and is based on early stage cancer recognition.

Keywords: Lynch syndrome, HNPCC, microsatelites instability (MSI), immunohistochemistry (IHC), MMR genes, preventive care.