Original Research Article
Effects of Metformin Dose on Cancer Risk Reduction in Patients with Type 2 Diabetes Mellitus: A 6-Year Follow-up Study
Article first published online: 17 JUL 2013
© 2013 Pharmacotherapy Publications, Inc.
Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy
Volume 34, Issue 1, pages 36–45, January 2014
How to Cite
(Pharmacotherapy 2014;34(1):36–45) doi: 10.1002/phar.1334
- Issue published online: 8 JAN 2014
- Article first published online: 17 JUL 2013
- Taipei Medical University. Grant Number: TMU98-AE1-B20
- dose effect;
- type 2 diabetes
To explore the effects of metformin dose on cancer risk reduction in patients with type 2 diabetes.
Population-based cohort study.
National Health Insurance program Longitudinal Health Insurance Database.
A total of 65,754 age- and gender-matched patients without diabetes and no previous cancer diagnosis were extracted from the database.
Measurements and Main Results
We compared cancer risk among the subjects who had no diabetes, had type 2 diabetes but were not on diabetes drugs, used metformin only, used antidiabetic drugs other than metformin, or used metformin in combination with other antidiabetic drugs. Our results revealed dose-dependent effects of metformin on cancer risk and cancer onset times. A significant decrease in cancer risk was found in the monotherapy group who received more than 360 defined daily doses (DDDs) of metformin (hazard ratio [HR] 0.40, 95% confidence interval [CI] 0.24–0.66). The greatest decrease in cancer risk was observed in patients who took more than 1080 DDDs (HR 0.27, 95% CI 0.09–0.84). Significantly greater dose-dependent effects were seen in patients who used metformin in combination with other antidiabetic drugs.
The magnitude of cancer risk reduction and prolonged cancer onset times produced by metformin in patients with type 2 diabetes depended on the dose of metformin, regardless of whether metformin was used alone or combined with other antidiabetic drugs.