After diagnosed of endometrial atypical hyperplasia(EAH) or type I endometrial cancer(EC) by dilatation and curettage (D&C) or hysteroscopy, patients will be enrolled. Age, waist circumstances, blood pressure, basic history of infertility, blood pressure, serum lipid level and side effects will be collected. Blood tests, including triglycerides, high density lipoprotein-cholesterol, fasting blood glucose, liver and kidney function will be performed before treatment to evacuate their metabolic conditions.~Patients are randomized to 1 of 2 treatment groups. Patients will receive metformin 500 mg by mouth third daily and megestrol acetate 160 mg by mouth daily for 3 months on Arm I. Patients will receive megestrol acetate 160 mg PO daily for 3 months on Arm II. Then an hysteroscope will be used to evaluate the endometrial condition, and the findings will be recorded. For patients with EAH, complete response (CR) is defined as the reversion of endometrial atypical hyperplasia to proliferative or secretory endometrium; partial response (PR) is defined as regression to simple or complex hyperplasia without atypia; no response (NR) is defined as the persistence of the disease; and progressive disease (PD) is defined as the appearance of endometrial cancer in patients. EAH after treatment will be defined as PR in patients with EC. Continuous therapies will be needed in PR, NR or PD.~After completion of study treatment, 3 months of maintenance treatment will be recommended for patients with CR, and they will be followed up for 2 years.~In addition, we've already had a pilot study in 19 patients primarily diagnosed of endometrial atypical hyperplasia from August 2012 to April 2013. 10 patients were in Arm I and 9 patients were in Arm II. Metabolic syndrome were evaluated among all subjects. After treatment, megestrol acetate plus metformin worked better than megestrol acetate alone. But two arms showed no difference in NR patients, which may suggest metformin just worked as an antitumor drug more than an insulin sensitizer. More supportive researches are needed to verify it.
The purpose of this study is to see if megestrol acetate plus metformin will be more effective in returning the endometrial tissue to a normal state than megestrol acetate alone in patients with endometrial atypical hyperplasia or early stage endometrial adenocarcinoma.