1. Department of Obstetrics and Gynecology, Faculty of Medicine, Oita University, Oita, Japan.
2. Cancer Biostatistics Laboratory, Clinical Research Institute, National Kyusyu Cancer Center, Fukuoka, Japan.
3. Division of Obstetrics and Gynecology, Support System for Regional Medicine, Oita University, Oita, Japan.
4. Department of Obstetrics and Gynecology, University of Tsukuba, Ibaraki, Japan.
5. Division of Gynecology, Hyogo Cancer Center, Hyogo, Japan.
6. Department of Obstetrics and Gynecology, Hirosaki University Graduate School of Medicine, Aomori, Japan.
7. Department of Obstetrics and Gynecology, Tokyo Women's Medical University Medical Center East, Tokyo, Japan.
8. Department of Obstetrics and Gynecology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
9. Department of Pathology, Saitama Medical University International Medical Center, Saitama, Japan.
10. Department of Obstetrics and Gynecology, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan.
11. Division of Gynecology, National Hospital Organization Shikoku Cancer Center, Ehime, Japan.
12. Department of Obstetrics and Gynecology, St. Marianna University School of Medicine, Kanagawa, Japan.
13. Department of Obstetrics and Gynecology, Osaka University, Osaka, Japan.
14. Department of Obstetrics and Gynecology, Tottori University, Tottori, Japan.
15. Department of Obstetrics and Gynecology, Tohoku University, Miyagi, Japan.
16. Department of Obstetrics and Gynecology, Nara Medical University, Nara, Japan.
17. Department of Obstetrics and Gynecology, Kansai Rosai Hospital, Hyogo, Japan.
18. Department of Obstetrics and Gynecology, Kurume University, Fukuoka, Japan.
19. Department of Obstetrics and Gynecology, Nagoya City University, Aichi, Japan.
20. Department of Obstetrics and Gynecology, Kuwana City Medical Center, Mie, Japan.
21. Department of Pathology, Osaka Medical College, Osaka, Japan.
22. Division of Pathology, National Hospital Organization Shikoku Cancer Center, Ehime, Japan.