Long-Term patterns of cancer incidence among patients with and without type 2 diabetes in the United Kingdom

Aims: Studies using contemporary cohorts are needed to assess the association between type 2 diabetes and cancer. Methods: Using the United Kingdom Clinical Practice Research Datalink, we matched patients with type 2 diabetes between 1988 and 2019 to patients without type 2 diabetes. Poisson regression models were fit to estimate incidence rate ratios (IRRs) with 95% confidence intervals (CIs) for cancer. In secondary analyses, we determined whether the strength of the association varied with calendar time and whether patients with type 2 diabetes had a higher incidence of being diagnosed with multiple cancers during the follow-up period. Results: 890,214 patients with type 2 diabetes were matched to an equal number of patients without type 2 diabetes. Patients with type 2 diabetes had a higher cancer incidence than patients without type 2 diabetes (IRR 1.19, 95% CI 1.18-1.21). The IRR was higher 2010 onwards (IRR: 1.25, 95% CI: 1.23-1.28) compared with the association in previous years. Overall, patients with type 2 diabetes had a 5% higher incidence of being diagnosed with multiple cancers (IRR: 1.05, 95% CI: 1.04-1.07). Conclusions: The results of this large population-based study indicate that type 2 diabetes is associated with an increased risk of several cancers.