Cancer Risk Associated with Use of Metformin and Sulfonylurea in Type 2 Diabetes: A Meta-Analysis Full Text
The Oncologist, 06/22/2012
Evidence Based Medicine
Soranna D et al. – Metformin, but not sulfonylurea, appears to reduce subsequent cancer risk. This has relevant implications in light of the exploding global epidemic of diabetes.Methods
- The authors performed a MEDLINE search for observational studies that investigated the risk of all cancers and specific cancer sites in relation to use of metformin and/or sulfonylurea among patients with type 2 diabetes mellitus.
- Fixed- and random-effect models were fitted to estimate the summary relative risk (RR).
- Between-study heterogeneity was tested using χ2 statistics and measured with the I2 statistic.
- Publication bias was evaluated using funnel plot and Egger's regression asymmetry test.
- Seventeen studies satisfying inclusion criteria and including 37,632 cancers were evaluated after reviewing 401 citations.
- Use of metformin was associated with significantly decreased RR of all cancers (summary RR 0.61, 95% confidence interval [CI] 0.54–0.70), colorectal cancer (0.64, 95% CI 0.54–0.76), and pancreatic cancer (0.38, 95% CI 0.14–0.91).
- With the exception of colorectal cancer, significant between-study heterogeneity was observed.
- Evidence of publication bias for metformin-cancer association was also observed.
- There was no evidence that metformin affects the risk of breast and prostate cancers, nor that sulfonylurea affects the risk of cancer at any site.