Metformin for the Treatment of Insulin Resistance in Women With Stage I-III Breast Cancer Completing Chemotherapy

This phase III trial evaluates how often women develop insulin resistance and type-2 diabetes and compares metformin with usual care to usual care alone in treating insulin resistance in women with stage I-III breast cancer after chemotherapy. Insulin resistance occurs when cells stop responding to insulin and is a risk factor for developing diabetes and heart disease. Higher levels of insulin have been shown to be associated with aggressive breast cancer. Metformin hydrochloride decreases the amount of glucose (a type of sugar) released into the bloodstream from the liver and increases the body's use of the glucose. Metformin as well as standard of care diet and exercise education is known to lower blood sugar. However, chemotherapy may accelerate metabolic disorders, such as high blood sugar, and the impact of metformin in these breast cancer survivors is not known. Giving metformin with usual care may be more effective than usual care alone in preventing or reversing insulin resistance in women with stage I-III breast cancer after chemotherapy.

NCT Number	NCT06763328
Lead Sponsor	City of Hope Medical Center Collaborators: National Cancer Institute (NCI)
Conditions	Anatomic Stage I Breast Cancer AJCC v8, Anatomic Stage II Breast Cancer AJCC v8, Anatomic Stage III Breast Cancer AJCC v8, Invasive Breast Carcinoma
Enrollment	80 participants
Start Date	2024-12-16
Primary Completion	2029-06-16 (estimated)
Study Completion	2029-06-16 (estimated)
Updated on ClinicalTrials.gov	2026-06-12