Metformin Is Not Associated with Incidence Risk of Non-Hodgkin Lymphomas among Diabetic Patients.

Background: Several epidemiological studies have shown a positive association between diabetes and increased risk of non-Hodgkin lymphoma (NHL), but the effect of diabetic treatment drugs such as metformin on the risk is unknown. Methods: We conducted a population-based nested casecontrol study involving 878 NHL cases and 4,364 controls diagnosed with diabetes. Use of metformin and other medications before diagnosis and medical condition histories were assessed using administrative databases. We used conditional logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for use of metformin, adjusting for confounders. Results: Risk of total NHLs is not associated with ever use of metformin(OR, 0.93; 95% CI, 0.79-1.10) among diabeticpatients. NHL subtypes were also not associated with metformin use. Conclusions: Metformin use is not associated with overall or subtype NHL risk among diabetic patients. Impact: NHLs are etiologically heterogeneous and larger scale studies are warranted to test the potential effect of metformin byNHLsubtype. (C) 2018 AACR.