1. Department of General Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China
2. Liver Cancer Institute, Zhongshan Hospital of Fudan University, Shanghai 200032, P.R. China
3. Department of Gastroenterology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
4. Department of General Surgery, Lu'an Affiliated Hospital of Anhui Medical University, Lu'an, Anhui 237005, P.R. China