Journal Article

A randomized controlled trial of metformin in women with components of metabolic syndrome: intervention feasibility and effects on adiposity and breast density

Chalasani Pavani, Thomson, Cynthia A, Algotar, Amit M, Huang, Chuan, Centuori, Sara, Roe, Denise J, Jean-Phillippe, Galons, Altbach, Maria, Sherry, Chow H-H, Martinez, Jessica A, Trujillo, Jesse, Tapia, Edgar, Villa-Guillen, Diana Evelyn, Guillen-Rodriguez, Jose, Pinto Liane

2021

Overview

PurposeObesity is a known risk factor for post-menopausal breast cancer and may increase risk for triple negative breast cancer in premenopausal women. Intervention strategies are clearly needed to reduce obesity-associated breast cancer risk.MethodsWe conducted a Phase II double-blind, randomized, placebo-controlled trial of metformin in overweight/obese premenopausal women with components of metabolic syndrome to assess the potential of metformin for primary breast cancer prevention. Eligible participants were randomized to receive metformin (850 mg BID, n = 76) or placebo (n = 75) for 12 months. Outcomes included breast density, assessed by fat/water MRI with change in percent breast density as the primary endpoint, anthropometric measures, and intervention feasibility.ResultsSeventy-six percent in the metformin arm and 83% in the placebo arm (p = 0.182) completed the 12-month intervention. Adherence to study agent was high with more than 80% of participants taking ≥ 80% assigned pills. The most common adverse events reported in the metformin arm were gastrointestinal in nature and subsided over time. Compared to placebo, metformin intervention led to a significant reduction in waist circumference (p < 0.001) and waist-to-hip ratio (p = 0.019). Compared to placebo, metformin did not change percent breast density and dense breast volume but led to a numerical but not significant decrease in non-dense breast volume (p = 0.070).ConclusionWe conclude that metformin intervention resulted in favorable changes in anthropometric measures of adiposity and a borderline decrease in non-dense breast volume in women with metabolic dysregulation. More research is needed to understand the impact of metformin on breast cancer risk reduction.Trial registrationClinicalTrials.gov NCT02028221. Registered January 7, 2014, https://clinicaltrials.gov/ct2/show/NCT02028221

• Publisher: Springer Nature B.V
• Subject: Adipose tissue / Adverse events / Anthropometry / Antidiabetics / Body measurements / Body weight / Breast cancer / Cancer research / Magnetic resonance imaging / Menopause / Metabolic syndrome / Metformin / Obesity / Overweight / Placebos / Post-menopause / Risk factors