Clinical efficacy and safety of adjuvant immunotherapy (Tislelizumab) plus chemotherapy vs. adjuvant chemotherapy alone in lymph node-positive patients with gastric cancer after D2 radical resection: a prospective, 2-arm, phase II study.

This study aims to investigate the effectiveness and safety of adjuvant Tislelizumab (BeiGene China Co., Ltd, Changping District, Beijing, China) in combination with chemotherapy for patients with localized lymph node-positive disease following D2 (extended lymphadenectomy) radical gastrectomy for gastric cancer.Patients with lymph node-positive gastric cancer who underwent D2 radical gastrectomy at Yixing People's Hospital between April 2021 and June 2022 were selected and enrolled in the study. They were divided into the study group, which received immunotherapy (Tislelizumab) in combination with chemotherapy (XELOX regimen: Xeloda plus Oxaliplatin), or the control group, which received chemotherapy alone (XELOX regimen). Adverse events, disease-free survival (DFS), and overall survival (OS) were observed. This study was registered on ClinicalTrials.gov (ClinicalTrials.gov Identifier: NCT05844371).The one-year disease-free survival (DFS) rate was 81.82% in the study group compared to 71.43% in the control group. Although the DFS rate tended to be higher in the study group, the difference did not reach statistical significance (p=0.388, HR=0.573, 95% CI: 0.161-2.032). Patients in both groups tolerated the treatment well. Both groups exhibited similar rates of neutropenia, hemoglobin depletion, gastrointestinal reactions, abnormal liver function, and peripheral neuritis. The majority of adverse events in both groups were grade 1-2, with only hypothyroidism showing a significant difference (p=0.021). The only statistically significant difference in grade 3-4 adverse events was thrombocytopenia (p=0.048). All adverse reactions were effectively managed with symptomatic treatment.The addition of adjuvant PD-1 inhibitor (Tislelizumab) to XELOX therapy showed a favorable impact on the one-year disease-free survival (DFS) rate when compared to adjuvant XELOX chemotherapy alone in patients with regional lymph node-positive disease after D2 radical gastrectomy. Moreover, patients were able to tolerate the accompanying adverse effects, which were deemed safe.