Statins and the risk of gastric cancer in diabetes patients

Background: Several studies have suggested a cancer risk reduction in statin users although the evidence remains weak for stomach cancer. The purpose of this study was to use an exact-matching case-control design to examine the risk of gastric cancer associated with the use of statins in a cohort of patients with diabetes. Methods: Cases were defined as patients with incident gastric cancer identified by International Classification of Diseases 16.0 similar to 16.9 recorded at Samsung Medical Center database during the period of 1999 to 2008, at least 6 months after the entry date of diabetes code. Each gastric cancer case patient was matched with one control patient from the diabetes patient registry in a 1:1 fashion, blinded to patient outcomes. Results: A total of 983 cases with gastric cancer and 983 controls without gastric cancer, matched by age and sex, were included in the analysis. The presence of prescription for any statin was inversely associated with gastric cancer risk in the unadjusted conditional logistic regression model (OR: 0.18; 95% CI: 0.14 - 0.24; P < .0001). Multivariate analysis using conditional logistic regression with Bonferroni's correction against aspirin indicated a significant reduction in the risk of gastric cancer in diabetes patients with statin prescriptions (OR: 0.21; 95% CI: 0.16 -0.28; P < .0001). After adjustment for aspirin use, a longer duration of statin use was associated with reduced risk of gastric cancer, with statistical significance (P<.0001). Conclusions: A strong inverse association was found between the risk of gastric adenocarcinoma and statin use in diabetic patients.