Gastrointestinal cancer incidence in Type 2 Diabetes Mellitus; Results from a large retrospective population-based cohort study in the UK

Abstract

Background: Type 2 diabetes mellitus (T2DM) has been suggested as a risk factor for liver, pancreatic, and colorectal cancer. T2DM patients show higher incidences of these cancers compared to the non-diabetic (non-DM) population. Current evidence, however, is inconsistent with respect to the incidences of other gastrointestinal (GI) malignancies. Objectives: To determine incidence rates (IRs) of all GI cancers in patients with and without T2DM. Methods: A retrospective cohort study was conducted using the UK Clinical Practice Research Datalink (CPRD) during 1988-2012. A T2DM cohort of antidiabetic drug users was matched to a non-DM reference cohort, by age, sex, and practice. Crude incidence rates (IRs) per 100,000 person-years (105 py) and 95% confidence intervals (CI) were calculated, stratified by age, sex, and calendar period. IRs were compared using the normal theory test. Results: 333,438 T2DM subjects and 333,438 non- DM subjects were analyzed, with a total duration of follow-up of >3.6 million py and 10,977 observed GI cancer cases. Overall, IRs of any GI cancer (IR 330 vs. 276 per 105 py), liver cancer (IR 26 vs. 8.9 per 105 py), pancreatic cancer (IR 65 vs. 31 per 105 py), and colon cancer (IR 119 vs. 109 per 105 py) were significantly higher in the T2DM cohort compared to the non-DM cohort, whereas the IR of esophageal cancer was significantly lower (IR 41 vs. 47 per 105 py, p