1. Department of Gynecology, The First Hospital of China Medical University, Shenyang, People's Republic of China.
2. Department of Health Statistics, School of Public Health, China Medical University, Shenyang, People's Republic of China.
3. Department of Pathology, The First Hospital and College of Basic Medical Sciences, China Medical University; Institute of Pathology and Pathophysiology, China Medical University, Shenyang, People's Republic of China.