1. Department of Obstetrics and Gynecology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Hongkou, Shanghai 200080, P.R. China
2. Department of General Surgery, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Hongkou, Shanghai 200080, P.R. China
3. Department of General Surgery, Dongtai People's Hospital, Dongtai, Jiangsu 224200, P.R. China
4. Department of Pathology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Hongkou, Shanghai 200080, P.R. China