Background/Objectives: Gastric cancer (GC) remains a major global health burden, but its long-term association with pneumonia risk has not been comprehensively investigated. This study aimed to evaluate the long-term risk of pneumonia among GC survivors using a nationwide Korean cohort, focusing on chronic post-cancer susceptibility rather than perioperative or treatment-related complications. Methods: We conducted a nationwide, population-based cohort study using the Korean National Health Insurance Service database, including 9212 GC patients and 36,848 age-, sex-, income-, and region-matched controls (1:4 ratio). Participants were followed for up to 17 years. Propensity score overlap weighting was applied to minimize confounding, achieving exact covariate balance and optimal precision, with standardized differences used to confirm balance. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for pneumonia were estimated via Cox proportional hazards models. Results: During follow-up from 2002–2003 through 2019 (maximum 17 years), GC showed a significant relationship with increased risk of pneumonia (aHR 1.06; 95% CI: 1.01–1.11;p= 0.014). Subgroup analyses revealed higher risks among men, socioeconomically disadvantaged individuals, urban residents, and unexpectedly, patients without comorbidities. Conclusions: This large nationwide cohort study demonstrated that GC may be linked to a slightly elevated long-term risk of pneumonia, varying across demographic and clinical subgroups. These findings underscore the need for continued respiratory health monitoring in GC survivors while acknowledging that the observed association may be influenced by underlying comorbidities and survivorship factors.
背景/目的：胃癌（GC）仍是全球重大健康负担，但其与肺炎风险的长期关联尚未得到全面研究。本研究旨在利用韩国全国性队列评估胃癌幸存者的肺炎长期风险，重点关注癌症后的慢性易感性，而非围手术期或治疗相关并发症。方法：我们基于韩国国民健康保险服务数据库开展全国性人群队列研究，纳入9212例胃癌患者及按年龄、性别、收入、居住地1:4匹配的36848例对照。随访时间最长17年。采用倾向评分重叠加权法控制混杂因素，实现协变量精确平衡与最优精确度，并通过标准化差异确认平衡效果。使用Cox比例风险模型估计肺炎的校正风险比（aHR）及95%置信区间（CI）。结果：在2002–2003年至2019年（最长17年）的随访期间，胃癌与肺炎风险升高显著相关（aHR 1.06；95% CI：1.01–1.11；p=0.014）。亚组分析显示男性、社会经济弱势群体、城市居民以及无合并症患者（此结果出人意料）的肺炎风险更高。结论：这项大规模全国性队列研究表明，胃癌可能与肺炎长期风险的轻微升高存在关联，且这种关联在不同人口学和临床亚组中存在差异。研究结果提示需要对胃癌幸存者进行持续的呼吸健康监测，同时应认识到观察到的关联可能受到潜在合并症及生存状态因素的影响。
肿瘤(癌症)患者之家