1. Department of Obstetrics and Gynecology, Tohoku University Hospital, 1-1, Seiryomachi, Sendai 980-8574, Japan
2. Tohoku Medical Megabank Organization, Tohoku University, 2-1, Seiryomachi, Sendai 980-8573, Japan
3. Division of Gynecology, Miyagi Cancer Center, 47-1, Nodayama, Medeshima-Shiode, Natori 981-1293, Japan