Microsatellite Instability and Programmed Cell Death-Ligand 1 Expression in Stage ll/lll Gastric Cancer Post Hoc Analysis of the CLASSIC Randomized Controlled study

摘要

Objective: We investigated microsatellite instability (MSI) status and programed cell death ligand 1 (PD-L1) expression as predictors of prognosis and responsiveness to chemotherapy for stage n/HI gastric cancer. Background: The clinical implications of MSI status and PD-L1 expression in gastric cancer have not been well-elucidated. Methods: Tumor specimens and clinical information were collected from patients enrolled in the CLASSIC trial-a randomized controlled study of capecitabine plus oxaliplatin-based adjuvant chemotherapy. Five quasi-mono-morphic mononucleotide markers were used to assess tumor MSI status. PD-LI expressions of tumor and stromal immune cells were evaluated using immunohistochemistry.