Metformin for Stage IV Cancer
Also known as: Glucophage
Epidemiological data shows reduced cancer incidence in diabetic patients on metformin, spurring repurposing investigation.
Mechanism of Action
Metformin activates AMPK by inhibiting mitochondrial Complex I, suppressing mTOR signaling, reducing hepatic glucose production, and inhibiting cancer cell proliferation through NF-κB suppression, HIF-1α inhibition, and cell cycle arrest. It may also modulate the tumor immune microenvironment.
General mechanism: AMPK activator via Complex I inhibition. Reduces mTOR signaling, glucose production, and inflammatory pathways.
Current Evidence
TAME (Targeting Aging with Metformin) trial ongoing. Multiple cancer-adjunctive trials. Epidemiological data is compelling but prospective clinical trial data for cancer is still emerging.
Clinical Status: FDA-approved for diabetes. Cancer repurposing in Phase II/III trials. TAME trial for aging-related disease prevention.
Safety Profile
GI effects (diarrhea, nausea). Lactic acidosis risk (rare). B12 depletion with long-term use. Contraindicated in severe renal impairment.
Key Research Questions
- Does metformin's anti-cancer effect require hyperglycemia/insulin resistance, or is it independent?
- Can metformin sensitize tumors to immunotherapy?
- What metabolic subtype of cancer responds best to AMPK activation?
Frequently Asked Questions
Can metformin prevent cancer?
Epidemiological studies show diabetic patients on metformin have 20-40% lower cancer incidence. Metformin activates AMPK, inhibits mTOR, and reduces insulin/IGF-1 signaling — all relevant to cancer prevention. The TAME trial is studying metformin for aging and age-related diseases including cancer.
What is the TAME metformin trial?
TAME (Targeting Aging with Metformin) is a landmark clinical trial testing whether metformin can delay age-related diseases including cancer, cardiovascular disease, and dementia in non-diabetic adults aged 65-79. It's the first FDA-approved trial targeting aging as a condition.
Metformin dosage for longevity
Longevity-focused protocols typically use 500-1500mg daily, lower than the diabetes dose of 2000mg. Extended-release formulations reduce GI side effects. Vitamin B12 monitoring is recommended with long-term use.