- A meta-analysis finds that metformin boosts OS and cancer-specific survival in patients with colorectal cancer (CRC) and type 2 diabetes (T2D).
Why this matters
- Basic research suggests that metformin could inhibit cancer cell proliferation and metabolism, as well as angiogenesis, but clinical studies have yielded inconsistent results.
- Meta-analysis of 10 studies (n=10,123) of CRC and T2D.
- Funding: Natural Science Foundation of Zhejiang Province.
- The quality of the included studies ranged from moderate to high, based on Newcastle-Ottawa's statement (overall quality score, 6-9).
- OS odds ratios ranged from 0.23 to 1.65 in the 10 included studies.
- The pooled analysis showed better OS in metformin users than nonusers (OR, 0.54; 95% CI, 0.47-0.63).
- There was between-study heterogeneity (I2=50%; P=.04), but sensitivity analyses excluding specific studies did not alter the findings.
- Meta-analysis of 4 studies that reported cancer-specific mortality revealed an advantage for metformin use (OR, 0.59; 95% CI, 0.43-0.82).
- Limited to cohort studies that cannot prove causation.