Risk factors for gastric cancer: a large-scale, population-based case-control study

Background: Early detection of gastric cancer (GC) has been the topic of major efforts in China. This study aimed to explore the risk factors associated with GC and to provide evidence for the selection of a high-risk population of GC.Methods: Based on the cancer screening cohort of the National Cancer Screening Program in Urban China, GC patients diagnosed by endoscopy and pathological examinations constituted the case group, and controls were 1:3 matched by sex and age (±5 years) individually. The variables were selected by univariable analysis of factors such as body mass index (BMI), dietary habits, lifestyle, stomach disease history, and family history of GC; and multivariable logistic regression was used to analyze the influencing factors of GC and to calculate the odds ratio (OR) of related factors and its 95% confidence interval (CI).Results: A total of 215 GC cases and 645 matched healthy controls were included in the final analysis, with a median age of 61 years for the case and control groups. Overall analysis showed that high educational level (above primary school) (OR = 0.362, 95% CI = 0.219-0.599,P < 0.001), overweight/obesity (BMI ≥24 kg/m2; OR= 0.489, 95% CI = 0.329-0.726,P < 0.001), cigarette smoking (OR = 3.069, 95% CI = 1.700-5.540,P < 0.001), alcohol consumption (OR = 1.661, 95% CI = 1.028-2.683,P = 0.038), history of stomach disease (OR = 6.917, 95% CI = 4.594-10.416,P < 0.001), and family history of GC in first-degree relatives (OR = 4.291, 95% CI = 1.661-11.084,P = 0.003) were significantly correlated with the occurrence of GC. Subgroup analyses by age and gender indicated that GC risk was still increased in the presence of a history of stomach disease. A history of chronic gastritis, gastric ulcer, or gastric polyposis was positively associated with GC, with adjusted ORs of 4.155 (95% CI = 2.711-6.368), 1.839 (95% CI = 1.028-3.288), and 2.752 (95% CI = 1.197-6.326).Conclusions: Subjects who smoke, drink, with history of stomach disease and family history of GC in first-degree relatives are the high-risk populations for GC. Therefore, attention should be paid to these subjects for GC screening.