Association between type 2 diabetes and cancer incidence in Taiwan: data from a prospective community-based cohort study

Aims: Evidence of a role for type 2 diabetes in overall cancer risk and risk for specific types of cancer is limited in ethnic Chinese populations. We therefore investigated whether there is an association between diabetes and cancer incidence in Taiwan. Methods: This study recruited a total of 3602 adults aged 35 years or over (average 54.9 ± 12.3 years, 52.8% women). Participants with fasting glucose ≥126 mg/dL, or taking hypoglycemic medications, were classed as having type 2 diabetes. Cancer incidence was established through regular follow-up interviews and medical records. Cox proportional hazard regression models were used to examine associations for diabetes with risk of all-cause and site-specific cancers. Results: During a median of follow-up of 10.5 years, 275 individuals developed cancer, including 157 digestive cancers and 31 urinary cancers. Younger participants (aged < 55 years) with diabetes had a greater risk of all cancers [adjusted relative risk (RR) 3.42; 95% confidence interval (CI), 1.78–6.57], digestive cancers (adjusted RR 2.88; 95% CI 1.15–6.94) and urinary cancers (adjusted RR 13.4; 95% CI 2.70–66.3) compared with individuals in the same age group without diabetes. Conclusions: Our results clearly demonstrate that middle-aged individuals of Chinese ethnicity with diabetes have a greater risk of all-cause cancer and specific subtypes of cancer.