Antidiabetic medications use and cancer risk in type 2 diabetes

Abstract

Introduction. The risk of several types of cancer is increased in type 2 diabetes mellitus (T2DM). Impact of antidiabetic medications on this risk is still a matter of controversies. The aim of our observational study was to evaluate the risk of cancer occurrence associated with the most frequently used antidiabetic agents. Material and methods. 213 patients (118 women) with T2DM who developed cancer while treated for diabetes and 213 subjects with T2DM without cancer, matched by age and gender in a 1:1 case-control manner were included. Date of cancer diagnosis was considered as index time, and for each comparator data from the same calendar time were used. Results. Both in the univariate and in multiple logistic regression analysis metformin use was associated with reduced cancer risk, while elevated risk associated with insulin use was significant only in univariate but not in multiple logistic regression analysis. Insulin and sulfonylurea derivatives in monotherapy were associated with significantly higher cancer risk compared to metformin monotherapy, while in combination with metformin this risk was attenuated to non-significant level. Conclusion. Our study suggests protective effect of metformin and potentially negative impact of insulin and sulfonylurea derivatives on cancer risk. These findings should be interpreted with caution, due to relatively small study group. Nevertheless, to minimize cancer risk associated with antidiabetic medications’ use, metformin should be continued as long as medically acceptable and it should be combined with insulin or SU to neutralize risk associated with using either of the latter drugs in monotherapy.