PD-L1 expression, tumor mutational burden, and microsatellite instability status in 746 pancreas ductal adenocarcinomas.

757 Background: Pancreas ductal adenocarcinomas (PDA) has a 5-year survival rate of 6% with a need for new therapeutic options. The approval of pembrolizumab for some gastrointestinal cancers shows the potential of immunotherapy (IMT) in PDA. We evaluated the IMT-associated biomarkers of PD-L1 expression, tumor mutational burden (TMB), microsatellite instability (MSI) and PD-L1 amplification in PDAs. Methods: 746 formalin-fixed paraffin embedded...