Abstract
We assessed gastric cancer risk in type 2 diabetes mellitus patients. Gastric cancer patients with diabetes between 2001–2012 were identified. Four groups were analysed: combination therapy with metformin users; insulin and other medication users; metformin and insulin users; and sulfonylurea users. Standardised incidence ratios (SIRs) for gastric cancers as a ratio of the observed number of cancer cases in people with diabetes to the expected number of cancer cases in the underlying general population were calculated. A total of 99,992 patients with diabetes were analysed and 337 gastric cancer cases in patients with diabetes were observed when compared to the expected number of 400.54 gastric cancer cases, according to the cancer rates of the general population (SIR 0.84, 95% confidence interval (CI): 0.76–0.94). Lower risk of gastric cancer was found both in male and female patients with diabetes, however, risk among females was insignificantly lower. Higher gastric cancer risk was found in the group of diabetic patients treated with sulfonylureas (SIR 1.31, 95% CI: 1.04–1.65) and significantly lower risk than expected from the general population was found in the group of metformin users (SIR 0.75, 95% CI: 0.66–0.86). Type 2 diabetes mellitus was not associated with increased risk of gastric cancer. Metformin might decrease the risk of gastric cancer in patients with diabetes, while sulfonylureas may increase gastric cancer risk.
Highlights
Gastric cancer is a deadly disease with over 1,000,000 new cases in 2018 and an estimated 783,000 deaths, making it the fifth most frequently diagnosed cancer and the third leading cause of cancer death [1]
There were no significant differences in risk of gastric cancer by age at type 2 diabetes mellitus diagnosis, except for the 60–69 years old female patient group, where gastric cancer risk was significantly lower than expected from the general population (SIR 0.77, 95% confidence intervals (CI): 0.64–0.93)
Our study revealed that type 2 diabetes mellitus was not associated with increased risk of gastric cancer (SIR 0.84, 95% CI: 0.76–0.94)
Summary
Gastric cancer is a deadly disease with over 1,000,000 new cases in 2018 and an estimated 783,000 deaths (equating to one in every 12 deaths globally), making it the fifth most frequently diagnosed cancer and the third leading cause of cancer death [1]. Obesity and type 2 diabetes mellitus have been linked to many types of cancer including gastric. This association has been primarily attributed to insulin resistance and cluster factors of metabolic syndrome, which play an additive carcinogenic role [4]. Some authors have hypothesised that the benefits of metformin on cancer among patients with type 2 diabetes mellitus are mediated by upregulation of MiR26b induced by metformin via reduction of insulin resistance [6,8,9]. Upregulation of AMPK directly suppresses mTOR, resulting in the inhibition of protein synthesis in cancer cells and cell proliferation [11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
