Histo-molecular characterization of pancreatic cancer with microsatellite instability: intra-tumor heterogeneity, B2M inactivation, and the importance of metastatic sites

Pancreatic ductal adenocarcinoma (PDAC) with microsatellite instability (MSI)/defective mismatch repair (dMMR) is the only subtype of pancreatic cancer with potential response to immunotherapy. Here, we report the histo-molecular characterization of MSI/dMMR PDAC with immunohistochemistry, MSI-based PCR, and next-generation sequencing. Five paradigmatic cases have been identified. The main results include the first report in pancreatic cancer of...