Abstract
BACKGROUND: In recent years, neoadjuvant immunotherapy (NAIT) has developed rapidly in patients with gastroesophageal junction cancer (GEJC). The suggested neoadjuvant treatment regimens for patients with GEJC may vary in light of the efficacy and safety results. METHODS: A search of the Cochrane Library, PubMed, Embase, and Web of Science was completed to locate studies examining the safety and effectiveness of NAIT for resectable GEJC. We analyzed the effect sizes (ES) and 95% confidence intervals (CI) in addition to subgroups and heterogeneity. Meta-analyses were performed using Stata BE17 software. RESULTS: For these meta-analyses, 753 patients were chosen from 21 studies. The effectiveness of NAIT was assessed using the pathological complete response (pCR), major pathological response (MPR), and nodal downstage to ypN0 rate. The MPR, pCR, and nodal downstage to ypN0 rate values in NAIT were noticeably higher (MPR: ES = 0.45; 95% CI: 0.36-0.54; pCR: ES = 0.26; 95% CI: 0.21-0.32; nodal downstage to ypN0 rate: ES = 0.60; 95% CI: 0.48-0.72) than those of neoadjuvant chemotherapy (nCT) or neoadjuvant chemoradiotherapy (nCRT) (MPR < 30%; pCR: ES = 3%-17%; nodal downstage to ypN0 rate: ES = 21%-29%). Safety was assessed using the treatment-related adverse events (trAEs) incidence rate, surgical delay rate, surgical complications incidence rate, and surgical resection rate. In conclusion, the incidence of trAEs, incidence of surgical complications, and surgical delay rate had ES values of 0.66, 0.48, and 0.09, respectively. These rates were comparable to those from nCT or nCRT (95% CI: 0.60-0.70; 0.15-0.51; and 0, respectively). The reported resection rates of 85%-95% with nCT or nCRT were comparable to the mean surgical resection rate of 90%. CONCLUSION: NAIT is an effective treatment for resectable GEJC; additionally, the level of NAIT toxicity is acceptable. The long-term effects of NAIT require further study.