Tislelizumab plus chemotherapy is an optimal option for second-line treatment for advanced gastroesophageal junction adenocarcinoma.

The development of programmed cell death receptor-1 and its ligand (PD-L1) have offered new treatment options for several cancers, but the clinical benefit of tislelizumab in the gastroesophageal junction (GEJ) adenocarcinoma is still murky. Thus, we aim to investigate the efficacy and safety of tislelizumab combined with chemotherapy in patients with GEJ cancer. In this study, 90 GEJ patients were retrospectively enrolled including 45 patients who received chemotherapy plus tislelizumab while 45 underwent chemotherapy only. Overall response rate (ORR), overall survival (OS), and progression-free survival (PFS) were estimated and safety was assessed by treatment-related adverse events between two arms. The ORR was significantly higher in the tislelizumab group than in patients with chemotherapy alone (71.1 vs. 44.4%). The PFS [54.7% (47.2-62.2) vs. 33.3% (26.3-40.3), P  = 0.047] and OS [62.1% (54.5-69.7) vs. 40.0% (32.5-47.5), P  = 0.031] were also significantly improved in patients with concomitant use of tislelizumab. When stratified by PD-L1 combined positive score (CPS), patients with PD-L1 CPS ≥ 1 also with significantly higher PFS and OS when taking tislelizumab ( P  = 0.015 and P  = 0.038). The incidence of hematologic toxicity was similar in the combination arm compared to the chemotherapy alone arm and the number of adverse events was not significantly increased by adding tislelizumab (all P  > 0.05). Concomitant use of tislelizumab and chemotherapy in GEJ patients may be with optimal therapeutic effect and similar incidence of adverse events than chemotherapy alone. Further studies with larger number of patients are warranted to confirm it.