Abstract Background Paradoxically, Helicobacter pylori–positive (HP+) advanced gastric cancer patients have a better prognosis than those who are HP–negative (HP-). Immunologic and statistical analyses can be used to verify whether systemic mechanisms modulated by HP are involved in this more favorable outcome. Methods A total of 658 advanced gastric cancer patients who underwent gastrectomy were enrolled. HP infection, mismatch repair, programmed death–ligand 1 (PD-L1) and CD4/CD8 proteins, and microsatellite instability were analyzed. Overall survival (OS) and relapse-free survival (RFS) rates were analyzed after stratifying clinicopathological factors. Cox proportional hazards regression analysis was performed to identify independent prognostic factors. Results Among 491 patients that were analyzed, 175 (36%) and 316 (64%) patients were HP+ and HP−, respectively. Analysis of RFS indicated an interaction of HP status among the subgroups for S-1 dose (Pinteraction = .049) and PD-L1 (P = .02). HP+ patients in the PD-L1- group had statistically higher 5-year OS and RFS than HP- patients (81% vs 68%; P = .0011; hazard ratio [HR] = 0.48, 95% confidence interval [CI] = 0.303 to 0.751, and 76% vs 63%; P = .001; HR = 0.508, 95% CI = 0.335 to 0.771, respectively). The 5-year OS and RFS was also statistically higher for HP+ compared with HP- patients in the "PD-L1- and S-1–r educed" group (86% vs 46%; P = .001; HR = 0.205, 95% CI = 0.07 to 0.602, and 83% vs 34%; P = .001; HR = 0.190, 95% CI = 0.072 to 0.498, respectively). Thus, HP status was identified as one of the most potentially important independent factors to predict prolonged survival. Conclusion This retrospective study suggests that an HP-modulated host immune system may contribute to prolonged survival in the absence of immune escape mechanisms of gastric cancer.

中文翻译：

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幽门螺杆菌通过 S-1 辅助化疗调节胃癌患者的宿主免疫

摘要 背景矛盾的是，幽门螺杆菌阳性 (HP+) 晚期胃癌患者的预后优于 HP 阴性 (HP-) 患者。免疫学和统计分析可用于验证 HP 调节的系统机制是否参与了这种更有利的结果。 方法共有 658 名接受胃切除术的晚期胃癌患者入组。分析了 HP 感染、错配修复、程序性死亡配体 1 (PD-L1) 和 CD4/CD8 蛋白以及微卫星不稳定性。对临床病理因素进行分层后，分析总生存率（OS）和无复发生存率（RFS）。进行 Cox 比例风险回归分析以确定独立的预后因素。 结果在接受分析的 491 名患者中，分别有 175 名 (36%) 和 316 名 (64%) 患者为 HP+ 和 HP−。RFS 分析表明 S-1 剂量 (Pinteraction = .049) 和 PD-L1 (P = .02) 亚组之间 HP 状态存在交互作用。PD-L1- 组中 HP+ 患者的 5 年 OS 和 RFS 显着高于 HP- 患者（81% vs 68%；P = .0011；风险比 [HR] = 0.48，95% 置信区间 [CI] = 0.303 至 0.751 和 76% vs 63%；P = .001；HR = 0.508，95% CI = 0.335 至 0.771。“PD-L1 和 S-1 降低”组中 HP+ 患者的 5 年 OS 和 RFS 也显着高于 HP- 患者（86% vs 46%；P = .001；HR = 0.205， 95% CI = 0.07 至 0.602，83% vs 34%；P = .001；HR = 0.190，95% CI = 0.072 至 0.498。因此，HP 状态被认为是预测延长生存期的最潜在重要的独立因素之一。 结论这项回顾性研究表明，在胃癌缺乏免疫逃逸机制的情况下，HP 调节的宿主免疫系统可能有助于延长生存期。