Metformin intervention in obese non-diabetic patients with breast cancer: phase II randomized, double-blind, placebo-controlled trial.

Abstract

Previous observational studies have suggested that metformin in diabetes patients may reduce breast cancer risk more than the reductions from other anti-diabetes medications. This randomized, double-blind, placebo-controlled trial was performed to evaluate the efficacy of metformin for controlling physical and metabolic profiles related to prognosis and adverse events in non-diabetic breast cancer patients. Female breast cancer patients (N = 105), at least 6 months post-mastectomy, with obesity (≥25 kg/m(2)) and/or pre-diabetes (fasting blood sugar levels ≥100 mg/dL), were randomly assigned to three groups (placebo, metformin 500 mg, and metformin 1000 mg) stratified by tamoxifen use. A linear mixed model for repeated measurements among three groups and ANOVA for profile differences during 6 months of treatment were used for the intention-to-treat analysis. The metformin 1000 mg group had a significantly greater decline in glucose and HbA1c levels between treatment weeks 0 and 6 month (p = 0.008 and 0.009, respectively), and the declines increased with an increase in body mass index (BMI) level (p interaction with BMI = 0.007 and 0.067, respectively). A marginally significant different effect from the metformin 1000 mg treatment was detected for glucose and HbA1c levels (p interaction = 0.084 and 0.063, respectively) in the intention-to-treat analysis. Metformin 1000 mg treatment had a favorable effect on controlling glucose and HbA1C levels in obese non-diabetic breast cancer patients, indicating prognostic importance. Further trials are needed to elucidate the risk-benefit ratio of long-term use of metformin.

• Authors: Kwang-Pil Ko, Seung Hyun Ma, Jae-Jeong Yang, Yunji Hwang, Choonghyun Ahn, Young-Min Cho, Dong-Young Noh, Byung-Joo Park, Wonshik Han, Sue K Park
• Journal: Breast cancer research and treatment (Breast Cancer Res Treat) Vol. 153 Issue 2 Pg. 361-70 (Sep 2015) ISSN: 1573-7217 [Electronic] Netherlands
• PMID: 26293146 (Publication Type: Clinical Trial, Phase II, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Biomarkers
• Hypoglycemic Agents
• Metformin

Topics

• Biomarkers
• Breast Neoplasms (complications, drug therapy, metabolism, pathology)
• Female
• Humans
• Hypoglycemic Agents (administration & dosage, adverse effects, therapeutic use)
• Metformin (administration & dosage, adverse effects, therapeutic use)
• Neoplasm Staging
• Obesity (complications)
• Time Factors
• Treatment Outcome