Microsatellite instability in patients with hepato-biliary-pancreatic malignancies in clinical practice (KHBO 1903).

MSI-high was detected in 4.6% of patients with hepato-biliary-pancreatic malignancies. There was a 50% objective response rate to pembrolizumab treatment for MSI-high cancers. The evaluation of MSI status by the current method using appropriately prepared tissue samples was to be a reliable and accurate approach to both the determination of MSI status and estimation of the effectiveness of pembrolizumab.