Research

Hormonal

Metformin use is associated with reduced cancer incidence and mortality in diabetic patients, with specific benefits observed in HER2-positive breast cancer and prostate cancer recurrence.

If you have type II diabetes, metformin is a standard treatment that may also offer protective benefits against certain cancers. Discuss with your doctor if metformin is appropriate for you, especially if you have a family history of breast or prostate cancer. Do not take metformin solely for cancer prevention if you do not have diabetes.

ModerateSupportsMEDIUM confidence
metformin has been associated with reduced total cancer incidence... and with decreased cancer-specific mortality... metformin use was associated with reduced breast cancer incidence and mortality... metformin use was associated with reduced risk of recurrence following primary therapy [prostate cancer]
Emma H. Allott et al. · Endocrine Related Cancer · 2015

Why this rating

Evidence is mixed across studies, with some showing protective effects and others null findings, particularly in non-diabetic or insulin-sensitive populations.

Source

Obesity and cancer: mechanistic insights from transdisciplinary studies

Emma H. Allott et al. · Endocrine Related Cancer · 2015

DOI 10.1530/erc-15-0400

narrative_reviewCited 178×
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DOI resolved against Crossref · corpus check 2026-06-10

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