Lynch syndrome: expanded tumor spectrum, universal screening and multimodal treatment strategies for colon cancer

A total of 15% to 20% of colorectal cancers are considered familial and Lynch syndrome (LS) accounts for 2% to 6% of all cases. Recently, microsatellite instability (MSI) has been identified in breast, bladder and prostate cancers of Lynch mutation carriers, thus expanding the tumor spectrum. Potential Lynch patients can be initially screened by testing their cancer specimen for MSI and mismatch repair (MMR) gene with immunohistochemistry (IHC). If positive, then genetic testing of these individuals are strongly encouraged, in order to guide treatment such as extended colectomy plus 5-Fluorouracil (5-FU) based adjuvant chemotherapy particularly for Stage III Lynch colon cancer. With increased clinician awareness and improved identification of LS patients, surgical and chemo therapies can be tailored and optimized for their survival benefit.