Phase 2
N=151
Phase II Study of Metformin for Reduction of Obesity-Associated Breast Cancer Risk
Breast Cancer Prevention
Bottom Line
View on ClinicalTrials.gov: NCT02028221 ↗Enrolled (actual)
151
Serious AEs
5.3%
Results posted
Mar 2021
Primary outcome: Primary: Change in Breast Density at 6 Months — -5.45; -13.71 cm^3
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 2
- Interventions
- Metformin (Drug); Placebo (Drug)
- Age
- Adult · 21+ yrs
- Sex
- Female
- Sponsor
- University of Arizona
- Primary completion
- Nov 2018
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Change in Breast Density at 6 Months |
-5.45; -13.71 | — |
| PRIMARY Change in Breast Density at 12 Months |
-12.11; -14.75 | — |
| SECONDARY Change From Baseline in Serum Insulin Levels at 6 and 12 Months |
14.6; 13.5; 14.0; 11.9; 13.1; 11.7 | — |
| SECONDARY Change From Baseline in Serum IGF-1 to IGFBP-3 Ratio at 6 and 12 Months |
0.178; 0.170; 0.178; 0.169; 0.171; 0.165 | — |
| SECONDARY Change From Baseline in Serum Testosterone Levels at 6 and 12 Months |
— | — |
| SECONDARY Change From Baseline in Serum Leptin to Adiponectin Ratio at 6 and 12 Months |
0.023; 0.028; 0.022; 0.025; 0.021; 0.026 | — |
| SECONDARY Change From Baseline in Body Weight at 6 and 12 Months |
102.3; 101.5; 102.1; 99.6; 103.2; 99.3 | — |
| SECONDARY Change From Baseline in Waist Circumference at 6 and 12 Months |
110.3; 111.2; 111.6; 108.9; 111.8; 108.3 | — |
| SECONDARY Change From Baseline in Serum IGF-2 Levels at 6 and 12 Months |
— | — |
Summary
Overweight and obesity are well established risk factors for breast cancer that develop after menopause. The increased postmenopausal breast cancer risk in women who are overweight or obese is likely to be attributed to multiple metabolic disturbances. Metformin is a commonly used medication in diabetics to stabilize blood sugar. Association studies and laboratory studies have shown its potential to reduce the risk for development of cancer, including breast cancer. Recent pilot clinical studies in breast cancer patients suggest that metformin may only be effective in overweight or obese women with metabolic disturbances. We propose to conduct a clinical study of metformin in overweight or obese premenopausal women with metabolic disturbances. Study participants will be randomly assigned to receive metformin or placebo for 12 months. The study will evaluate whether metformin can result in favorable changes in risk features that have been associated with increased breast cancer risk. The risk features that will be examined in our study include breast density, certain proteins and hormones, products of body metabolism, and body weight and composition. The study should help determine the potential breast cancer preventive activity of metformin in a growing population at risk for multiple diseases.
Eligibility Criteria
Inclusion Criteria
- Premenopausal women
- 21-54 years of age
- Have a BMI of 25 kg/m2 or greater
- No change in menstrual patterns for the past 6 months preceding the time of registration
- Waist circumference ≥ 35 inches or ≥ 31 inches for Asian Americans, individuals with polycystic ovary syndrome, or individuals with non-alcoholic fatty liver disease.
- Have at least one other component of metabolic syndrome (103) reported below:
- Elevated triglycerides (≥ 150 mg/dL (1.7 mmol/L) or on drug treatment for elevated triglycerides
- Reduced HDL-C ( 3 standard drinks/day)
- Have a history of allergic reactions to metformin or similar drugs
- Have a history of severe claustrophobia
- Have electrically, magnetically, or mechanically activated implants including cardiac pacemaker, cochlear implants, magnetic surgical clips or prostheses
- Have breast implants
Data sourced from ClinicalTrials.gov (NCT02028221). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.