Drug profile
Metformin
Biguanide that decreases hepatic glucose production and improves insulin sensitivity via AMPK activation.
Why this drug?
Beyond glycemic control, metformin modulates AMPK/mTOR signaling and has demonstrated anti-proliferative effects in preclinical cancer models, with observational cohorts suggesting reduced cancer incidence in diabetic patients.
Known risks
- Lactic acidosis (rare, especially with renal impairment)
- GI upset
- Vitamin B12 deficiency with long-term use
- Contraindicated in severe renal dysfunction
Evidence behind this
Observational studies suggest reduced cancer incidence; RCTs in adjuvant setting show mixed results.
Mechanism
AMPK activation suppresses mTOR-mediated proliferation in breast epithelial cells.
Authoritative sources
AI-generated summary
Metformin shows mechanistic plausibility and epidemiological support for breast cancer risk reduction, but prospective RCT evidence in treatment-naïve adjuvant settings remains inconclusive. Suitable for hypothesis generation and trial design, not clinical recommendation outside diabetes care.
- Decensi A et al., 2012
- Coleman CB et al., 2013
This summary is AI-assisted and human-reviewed. It does not constitute medical advice. Always consult authoritative sources and qualified professionals.