Inhibitory role of Metformin for tamoxifen induced ‎uterine cell proliferation in diabetic ‎patients with ER-‎positive Breast cancer

Abstract

The objective of the current work to evaluate the role of metformin in inhibiting the tamoxifen induced ‎endometrial ‎changes in diabetic patients with ER-positive breast cancer, a case-control study, carried out between December 2018 to May 2019, forty ‎diabetic women in postmenopausal phase with ER+ breast cancer on tamoxifen (20mg/day), ‎metformin ‎‎(1700 mg/day) GROUP A, and 40 diabetic patients with ER+ breast cancer on the ‎same dose of tamoxifen, but other hypoglycemic agent GROUP B, were selected as controls. ‎Uterine thickness was assessed by ultrasonography imaging at the beginning of treatment with ‎tamoxifen and after 2 years of treatment. Hysteroscopy ‎was done, and pathological findings also ‎recorded.‎ Mean uterine thickness of diabetic patients on other hypoglycemic was ‎significantly higher than diabetic patients on metformin (14.79±3.6 vs 4.37±1.8). Uterine ‎thickness >5mm were 2 (5%) vs ‎36 (85%) reported with the diabetic patient on metformin and the ‎diabetic patient on ‎other oral hypoglycemic group. Three cases (7.5%) of the diabetic patients ‎on other hypoglycemic agent were developed uterine polyps, and one case (2.5%) of diabetic ‎patients on metformin were developed uterine polyps. One case (2.5%) of uterine carcinoma ‎was reported with diabetic patients on other hypoglycemic group.‎ In conclusions metformin significantly inhibit tamoxifen-induced endometrial changes and ‎offers favorable endometrium protection.