MLH1 is deficient in a high proportion of patients with microsatellite instability (MSI-H). It has been shown that immunohistochemical analysis of MLH1 expression is a practical and reliable method for the routine detection of the vast majority of colorectal carcinomas with high-frequency MSI, which are frequently identified in hereditary nonpolyposis cancer (HNPCC) and are account for 15% of sporadic colorectal cancer. MLH1 negative tumors maybe associated with a longer disease-free survival.
MLH1 is deficient in a high proportion of patients with microsatellite instability (MSI-H). It has been shown that immunohistochemical analysis of MLH1 expression is a practical and reliable method for the routine detection of the vast majority of colorectal carcinomas with high-frequency MSI, which are frequently identified in hereditary nonpolyposis cancer (HNPCC) and are account for 15% of sporadic colorectal cancer. MLH1 negative tumors maybe associated with a longer disease-free survival.