Supplementary file 1_Impact of immune checkpoint inhibitors as neoadjuvant/perioperative therapy for locally advanced resectable gastric/gastroesophageal junction adenocarcinoma: a systematic review and meta-analysis.pdf

Background<p>Immune checkpoint inhibitor (ICI)-based neoadjuvant/perioperative strategies are expanding for locally advanced resectable gastric/gastroesophageal junction (G/GEJ) adenocarcinoma, but the evidence base differs substantially across strategies, and improved pathological response has not consistently translated into survival benefit. We aimed to synthesize strategy-specific comparative and prospective single-arm evidence.</p>Methods<p>PubMed, Web of Science, Embase, the Cochrane Library, and major oncology conference proceedings were searched from inception to August 3, 2026.

RCTs and prospective single-arm trials evaluating ICI-containing treatment initiated before surgery were included. Five strategies were evaluated: ICI plus chemotherapy (ICI+CT), ICI plus chemotherapy and anti-angiogenic therapy (ICI+CT+A), ICI plus chemoradiotherapy (ICI+CRT), ICI plus chemotherapy and anti-HER2 therapy (ICI+CT+H), and dual-ICI therapy (ICI+ICI). Random-effects comparative meta-analyses were conducted separately by strategy, while single-arm analyses provided descriptive absolute estimates.</p>Results<p>A total of 74 trials, including 16 RCTs and 58 prospective single-arm trials, were included.