Clinical, anamnestic, molecular and genetic criteria for Lynch syndrome

Lynch syndrome is the most common cancer-prone syndrome associated with a high risk of colorectal cancer (CRC), neoplasms of the upper gastrointestinal system, the urinary tract, the female reproductive system, brain tumours and others. The only known form of hereditary endometrial cancer is also diagnosed as part of Lynch syndrome. One or more pathogenic germline mutations in one of the mismatch repair (MMR) genes are the cause of Lynch syndrome. Mapping of MMR genes and the discovery of microsatellite instability (MSI) have given rise to the possibility of using these clue characteristics of the pathogenic process for the elaboration of a screening test for Lynch syndrome. Being highly accurate and superior to all previously developed clinical criteria and guidelines, MSI-testing along with the assessment of the expression patterns of MMR proteins by immunohistochemistry has taken the leading role in the early diagnosis of Lynch syndrome. This article focuses on a brief review about the main evolutionary stages of clinical, anamnestic, molecular and genetic criteria for Lynch syndrome together with the results of our own research on the accuracy of the Amsterdam criteria, the Bethesda guidelines and MSI-diagnostics in the determination of the indications for MMR-genotyping in colorectal cancer patients suspected for Lynch syndrome.