Promising clinical practices of metformin in women with PCOS and early-stage endometrial cancer.

Young women with polycystic ovary syndrome (PCOS) have a high risk of developing endometrial cancer (EC). There is an urgent need for non-surgical prevention and treatment strategies for these patients who fail to respond to progesterone treatment and wish to preserve their fertility. Recently, we have reported that the combined treatment with metformin and progesterone-based oral contraceptives has successfully reversed the early-stage EC into normal endometria in addition to improvement of insulin resistance in women with PCOS. More importantly, one of these treated women has successfully delivered a healthy newborn baby. However, before such treatment can be recommended to the clinical practice, the molecular basis of metformin in the endometrium under physiological and pathological conditions must be elucidated.