1. Department of Obstetrics and Gynecology, The Second Hospital of Hebei Medical University, Shijiazhuang, China;
2. Department of Gynecologic Oncology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China;
3. Key Laboratory of Cancer Prevention and Therapy, Tianjin, China;
4. National Clinical Research Centre of Cancer, Tianjin, China