Current data indicate that there is a significant risk of endometrial cancer (EC) in women with polycystic ovarian syndrome (PCOS), although further research needed to clarify the exact molecular mechanisms. Endometrial hyperplasia is a premalignant condition that usually heralds EC and it shares identical risk factors with EC. Metabolic syndrome with a triad of obesity, hyperinsulinaemia and diabetes, which is commonly observed in PCOS appears to be a key mechanism in EC pathogenesis. Measures to improve insulin resistance could therefore play a role in reducing the risk of EC in women with PCOS. Metformin is an insulin sensitising agent which is safe, widely available and currently licensed for type-2 diabetes. It has been clearly shown in both animal and human studies that metformin is of value in reversing endometrial hyperplasia. Metformin may therefore prevent EC in PCOS. This article reviews the use of metformin in reducing EC risk in PCOS and makes a case for future research on this topic.
The aim of this proof-of-concept study was to determine the effects of three-month Metformin therapy on the expression of tumor-regulatory genes (p53, cyclin D2 and BCL-2) in the endometrium of women with polycystic ovary syndrome (PCOS). A total of 40 women, aged between 21 and 45 years with PCOS (Rotterdam criteria) were recruited. The participants were assessed at pre- and 3-month-post-Metformin therapy for the menstrual regularities, weight reduction, Ferriman Galway scores, fasting blood glucose (FBG), total cholesterol, LDL, HDL and p53, BCL-2 and cyclin D2 gene expression. Five participants conceived spontaneously after the initial recruitment. Majority (68%) resumed regular menstrual cycles after Metformin. There were significant reduction in BMI (p = 0.001), weight (p = 0.001) and Ferriman Galway scores (p = 0.001). A significant improvement was seen in mean FBG (p = 0.002), total cholesterol (p = 0.001), LDL (p = 0.003) and HDL cholesterol levels (p = 0.015). Tumor suppressor gene (p53) was significantly up-regulated after Metformin (10 out of 14 women), with p value 0.016. BCL-2 and cyclin D2 (oncogenes) were slightly up-regulated without significant difference (p = 0.119 and 0.155, respectively). In conclusion, Metformin therapy improved clinical and metabolic parameters in women with PCOS and up-regulated p53 tumor suppressor gene significantly. Further studies are however required to independently validate our findings.
Matched MeSH terms: Endometrial Neoplasms/prevention & control