Rondell Graham, M.B.B.S., Head of Gastrointestinal and Liver Pathology at the Mayo Clinic - Preview 3
Microsatellite instability testing in #colon #cancer has evolved considerably over the past several years. It began as a way to screen for Lynch #Syndrome, a heritable condition, which accounts for about 5% of colon cancers. MSI subsequently has been shown to be a prognostic factor in colon cancer. And in its most recent incarnation as a biomarker, it has been shown to be predictive for response to immunotherapy. Pembrolizumab has been approved for patients with microsatellite instability-high tumors. Interestingly, or perhaps counter-intuitively, patients with microsatellite unstable tumors actually have a better prognosis. Why is this?
