The findings from previously published studies have suggested that radiation exposure is associated with increased mortality and incidence of gastric cancer. However, few cohort studies have incorporated risk factors such as Helicobacter pylori (H. pylori) infection or chronic atrophic gastritis (CAG). The current study is aimed at evaluating the modifying effect of CAG on radiation risk of noncardia gastric cancer by histological type, by reanalyzing data from a nested case–control study conducted within the longitudinal clinical cohort of atomic bomb survivors. The analysis was restricted to 297 intestinal- or diffuse-type noncardia cases and 873 controls rematched to the cases on gender, age, city, and time and type of serum storage, and countermatched on radiation dose. Multivariable-adjusted relative risks [95% confidence interval (CI)] of noncardia gastric cancer were 3.9 (2.1–7.2) for H. pylori IgG seropositivity with cytotoxin-associated gene A (CagA) IgG low titer, 2.6 (1.9–3.6) for CAG, 1.9 (1.3–2.8) for current smoking, and 1.4 (1.1–1.9) for 1 Gy irradiation. Among subjects without CAG, the relative risk (95% CI) of noncardia gastric cancer at 1 Gy was 2.3 (1.4–3.7), whereas relative risk (95% CI) at 1 Gy was 1.1 (0.8–1.5) among subjects with CAG (for the overall interaction, P = 0.012). By histological type, the risk at 1 Gy was high for diffuse type without CAG, with adjusted relative risk (95% CI) of 3.8 (2.0–7.6), but was not high for diffuse type with CAG or for intestinal-type irrespective of CAG status. The results indicate that radiation exposure is associated with increased risk of diffuse-type noncardia gastric cancer without CAG, and this association exists despite adjustment for H. pylori infection and smoking habit.

先前发表的研究结果表明，放射线照射与胃癌的死亡率和发生率增加有关。然而，很少有队列研究纳入了诸如幽门螺杆菌（H. pylori）的危险因素。）感染或慢性萎缩性胃炎（CAG）。本研究旨在通过重新分析在原子弹幸存者纵向临床队列中进行的嵌套病例对照研究的数据，通过组织学类型评估CAG对非心脏胃癌放射风险的改善作用。该分析仅限于297例肠型或弥漫型非心脏性病例，其中873例对照者在性别，年龄，城市，时间和血清贮藏类型方面与病例重新匹配，并在放射剂量上相匹配。幽门螺杆菌的非心脏胃癌多变量校正相对危险度[95％置信区间（CI）]为3.9（2.1–7.2）具有细胞毒素相关基因A（CagA）IgG低滴度的IgG血清阳性，CAG的2.6（1.9-3.6），目前吸烟的1.9（1.3-2.8），1 Gy辐射的1.4（1.1-1.9）。在没有CAG的受试者中，非心脏胃癌在1 Gy时的相对风险（95％CI）为2.3（1.4–3.7），而在1 Gy时非CCA患者的相对风险（95％CI）为1.1（0.8–1.5） （对于整体互动，P = 0.012）。按组织学类型，无CAG的弥散型在1 Gy时的风险较高，调整后的相对风险（95％CI）为3.8（2.0–7.6），但有CAG的弥散型或肠型在不考虑CG的情况下不高。 CAG状态。结果表明，辐射暴露与无CAG的弥漫型非心脏胃癌风险增加相关，尽管对幽门螺杆菌感染和吸烟习惯。