Efficacy and safety of PD-1 Monoclonal antibodies in the treatment of esophageal squamous cell carcinoma: Systematic review and meta Regression

Background: Esophageal Squamous Cell Carcinoma (ESCC) contributes to the global burden of disease. Conventional treatments such as surgical resection and chemotherapy offer limited longterm survival rates. Recently, immunotherapies targeting PD-1 have shown promise in other cancers, but their efficacy in ESCC remains unclear. Methods: The 31 studies eligible for this study included a total of 10,681 patients who were subjected to immunotherapy, either alone or in combination with traditional chemotherapy. A comprehensive search was conducted on September 1, 2023, across databases including CENTRAL, PubMed, MEDLINE, Web of Science, Embase, and Scopus. Results: For OSR, results indicate a significantly improved survival at different time points (6, 12, and 24 months), with an odds ratio of 0.636 (95 % CI 0.595-0.680; Z =-13.292; p < 0.00001). In terms of PFS, PD-1 inhibitors demonstrated improvements at different time points; pooled odds ratio was 0.568 (95 % CI 0.511-0.633; Z =-10.357; p < 0.00001). Regarding ORR, the pooled analysis showed an overall odds ratio of 1.724 (95 % CI 1.554-1.913; Z = 10.289; p < 0.00001), indicating improved treatment response. DCR did not suggest a significant advantage for PD-1 inhibitors over chemotherapy, with an odds ratio of 0.904 (95 % CI 0.784-1.043; Z =-1.381; p = 0.167). Conclusions: There is compelling evidence reinforcing the efficacy and safety of PD-1 inhibitors, as monotherapy or in combination with chemotherapy, for the treatment of ESCC. PD-1 inhibitors demonstrate a significant advantage in terms of OSR, PFS, and ORR.