Effect of metformin as an adjuvant therapy to letrozole on estradiol and other biomarkers involved in the pathogenesis of breast cancer in overweight and obese postmenopausal women: a pilot study.

Introduction: Metformin may provide a therapeutic benefit in different types of malignancy.

Purpose: We aimed at evaluating the effect of metformin as an adjuvant therapy to letrozole on estradiol and other biomarkers involved in the pathogenesis of breast cancer in overweight and obese postmenopausal women.

Methods: Seventy-five postmenopausal stages II-III breast cancer female patients were assessed for eligibility in an open-labeled parallel pilot study.