1. Department of Obstetrics and Gynecology; Showa University School of Medicine; Shinagawa-ku Tokyo 142-8666 Japan
2. Department of Obstetrics and Gynecology; Tohoku University Graduate School of Medicine; Sendai Japan
3. Department of Obstetrics and Gynecology; Keio University School of Medicine; Tokyo Japan
4. Gynecologic Oncology, Hyogo Cancer Center; Akashi Japan
5. Department of Gynecology; Cancer Institute Hospital; Tokyo Japan
6. Gynecology Service, National Kyushu Cancer Center; Fukuoka Japan
7. Department of Obstetrics and Gynecology; Kurume University School of Medicine; Kurume Japan
8. Department of Clinical Research Network; Clinical Research, Innovation and Education Center, Tohoku University Hospital; Sendai Japan
9. Department of Obstetrics and Gynecology; Kinki University; Osaka Japan
10. Department of Obstetrics and Gynecology; Faculty of Medicine, University of Tsukuba; Tsukuba Japan