Colorectal cancer: metformin boosts survival in patients with T2D

  • Cheng Y & al.
  • Clin Res Hepatol Gastroenterol
  • 9 Jul 2019

  • curated by Jim Kling
  • Univadis Clinical Summaries
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Takeaway

  • 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.

Study design

  • Meta-analysis of 10 studies (n=10,123) of CRC and T2D.
  • Funding: Natural Science Foundation of Zhejiang Province.

Key results

  • 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).

Limitations

  • Limited to cohort studies that cannot prove causation.