Adjuvant and neoadjuvant chemotherapy for MSI early gastric cancer: a systematic review and meta-analysis.

Abstract

Perioperative chemotherapy (CT) is an established therapeutic approach for patients diagnosed with stage IB-III gastric cancer (GC). This study aimed to investigate the efficacy of this approach in individuals with GC exhibiting high microsatellite instability (MSI-H). A systematic review was conducted, including studies that provided data on (neo)adjuvant CT outcomes in patients with MSI-H GC. Systematic searches were conducted in PubMed, Cochrane Central of Controlled Trials, and Embase databases. Data were aggregated using hazard ratios (HRs) to compare overall survival between CT and surgery. Data analysis from 23 studies, including 22,011 patients, revealed that the prevalence of MSI-H is 9.8%. Administration of adjuvant or perioperative CT did not significantly reduce the risk of death or relapse in patients with MSI-H GC (HR = 0.8, 95% CI 0.54-1.16; p = 0.24 and HR = 0.84, 95% CI 0.59-1.18; p = 0.31, respectively). Chemotherapy did not benefit patients diagnosed with MSI-H nonmetastatic GC but rather will be integrated with immune checkpoint inhibitors in the near future.