Highlights
Microsatellite instability-high/deficient mismatch repair (MSI-H/dMMR) tumors accounted for 5.1% of 1,638 tested gastroesophageal adenocarcinomas in this single-center cohort.
Immune checkpoint inhibitor-based therapy produced high activity in dMMR disease, with best objective response in 61.5% of evaluable metastatic cases and pCR/cCR in 52.2% of evaluable locoregional cases.
