1. Department of General Surgery, Xiangcheng People's Hospital, Suzhou, Jiangsu 215131, P.R. China
2. Department of Oncology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
3. Department of Oncology, Haimen People's Hospital, Haimen, Jiangsu 226100, P.R. China