PD-1 Inhibitor Plus Chemotherapy Versus Chemotherapy for First-Line Treatment in Advanced Esophageal Cancer: A Systematic Review and Meta-Analysis

Background: Immunotherapy combined with chemotherapy has recently changed the first-line treatment of several cancers. We perform a systematic meta-analysis to assess the efficacy and safety of PD-1 inhibitor plus chemotherapy for first-line treatment in advanced esophageal cancer.Methods: Data were collected from eligible studies searched from PubMed, Web of Science, Cochrane Library, Embase, American society of clinical oncology (ASCO) and the European Society for Medical Oncology (ESMO). Pooled hazard ratio (HR) for overall survival (OS) and progression-free survival (PFS), pooled odds ratio (OR) for objective response rate (ORR) and treatment-related adverse effects (TrAEs) were estimated to assess the efficacy and safety of PD-1 inhibitor plus chemotherapy versus chemotherapy. We performed several subgroup analyses to explore the variables on immunotherapy efficacy for esophageal cancer. The five-point Jadad scoring system and the bias risk assessment were used to evaluate the quality of studies, and sensitivity analyses were carried out to evaluate the robustness of the combined outcomes. Results: Seven records involving 3754 participants were selected in our study. Compared to chemotherapy group, the OS (HR=0.72; 95% CI: 0.66-0.78, PPPPP=0.05).Conclusion: Compared with chemotherapy, PD-1 inhibitor plus chemotherapy has an improvement of anti-tumor activity and controllable TrAEs for first-line treatment of advanced esophageal cancer.