1. Department of Obstetrics and Gynecology, Qilu Hospital, Shandong University, Ji'nan, Shandong, P.R. China
2. Gynecology Oncology Key Laboratory, Qilu Hospital, Shandong University, Ji'nan, Shandong, P.R. China
3. Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
4. Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
5. Shandong University School of Medicine, Ji'nan, Shandong, P.R. China