Metformin As a New Treatment Option in Medical Management of Benign Breast Disease - A Randomised Clinical Trial

Author(s): Prashant Dhannur, Mamata Rathod, Sunil Telkar, Ganesh Bhavikatti.

Introduction: Fibroadenosis and fibrocystic disease is the most common benign solid breast lump in women which has estrogen dependancy and proliferative features with no definite method of management. So far, no effective management strategy has been validated. Metformin has anti-estrogenic and antiproliferative properties. Thus, we investigated metformin as a new management strategy for fibroadenosis and fibrocystic disease (FCD).

Methods: In this randomized clinical trial study, eligible women with fibroadenosis were assigned randomly to the metformin (1000 mg daily), or the oil of evening primrose group for 3month. Breast physical and ultrasound exam was performed before and after the intervention (every 4 weeks), and the changes in the size of cysts and mastalgia were compared in the two groups.

Results: Overall, 46 patients in the treatment, and 44 in the placebo group completed the study. The mean age of participants was 32.4 years (±4.5), The amount of reduction in the size of cysts was two-fold in the treatment than second group. Mastalgia was also compared between two groups and was statistically not significant.

Conclusion: This study demonstrates the efficacy of Metformin in reducing the size of breast cysts in women with benign breast diseases, specifically fibroadenosis and fibrocystic disease (FCD). While the impact on mastalgia was less pronounced, the findings suggest that Metformin’s anti-estrogenic and antiproliferative properties effectively target the underlying pathophysiological mechanisms of these conditions.