Plasma Proteomic Biomarkers for Predicting Immunochemotherapy Outcomes in Advanced Gastric Adenocarcinoma

Immune checkpoint inhibitors (ICIs) plus chemotherapy are standard first-line therapy for advanced gastric (GC) and gastroesophageal junction cancer (GEJC), yet predictive biomarkers remain limited. In this prospective single-center study, 31 patients with advanced GC/GEJC receiving PD-1 inhibitor plus chemotherapy were enrolled. Plasma samples were collected at baseline and every two cycles. Immune-related proteins were quantified using the Olink Target 96 Immuno-Oncology panel.