Prognostic and predictive factors in advanced upper gastrointestinal cancer treated with immune checkpoint inhibitors: a systematic review and meta-analysis of the current evidence.

Background: Immune checkpoint inhibitors (ICIs) have shown encouraging treatment efficacy for upper gastrointestinal cancers (UGICs). However, durable clinical responses only existed in a minority of patients. We evaluated evidence predicting survival benefits to identify the optimal population followed by ICI-based therapy. Methods: A comprehensive search was performed using PubMed, Embase, Cochrane Library, and Web of Science to identify clinical trials for UGICs with ICI-based therapy. The outcomes were objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). The quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation System (GRADE). Results: Thirty-six studies comprising 12,440 patients were included for quantitative synthesis. Patients with PD-L1-positive (OR = 2.08, p < 0.00001), EBV+ (OR = 8.47, p = 0.003) tumors were more likely to respond to ICI treatment. Moreover, OS was significantly improved with the statistical subgroup difference concerning sex (p = 0.02) and region (p = 0.02). An exploratory subgroup analysis showed significantly improved OS with ICI plus chemotherapy in patients with CPS ≥ 10 (HR = 0.66, p = 0.001) and CPS ≥ 1 (HR = 0.75, p < 0.00001). Conclusion: UGIC patients with PD-L1-positive, EBV + status are associated with a better therapeutic response to ICI-based therapy. The male patients and Asian patients could derive more survival benefits following ICI treatment than female and non-Asian ones. A combination of prognostic and predictive factors was suggested to help guide immunotherapy decision-making in UGIC patients. [ABSTRACT FROM AUTHOR]