Efficacy of PD-1/PD-L1 inhibitors in patients with advanced gastroesophageal cancer: An updated meta-analysis based on randomized controlled trials

Background: This study aimed to investigate the clinical efficacy of programmed death-1 receptor and ligand-1 (PD-1/PD-L1) inhibitors in gastroesophageal cancer patients and the relationship between their clinicopathological features and curative treatment effects. Methods: A systematic search was conducted for articles published before April 2022 from online databases (PubMed, EMBASE, Web of Science and the Cochrane Library). The main outcome was overall survival (OS). Results: This meta-analysis comprised 16 studies involving 9,304 participants. The results indicated that compared with chemotherapy, patients treated with PD-1/PD-L1 inhibitors had significantly improved OS (HR = 0.80; p < 0.001) but no significant improvement in progression-free survival (PFS) (p = 0.185). Subgroup analyses demonstrated that PD-1/PD-L1 inhibitors combined with chemotherapy, esophageal squamous cell carcinoma, male, Asian patients and combined positive score (CPS) =1 were significantly associated with better survival outcomes. Further, subgroup analysis of gender revealed that the OS of all subgroups containing male patients was significantly improved compared with chemotherapy, unlike that of female patients. In addition, the line of therapy, Lauren classification, age and eastern cooperative oncology group (ECOG) performance status were not associated with PD-1/PD-L1 inhibitors efficacy. Conclusion: The results indicated that PD-1/PD-L1 inhibitors could prolong the OS of advanced gastroesophageal cancer patients. Clinicopathological features such as therapeutic schedules, tumor types, histological type, gender, geographical region and PD-L1 expression status (CPS) seemed to be associated with survival outcomes.