1. Department of General Surgery, The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong 510630, P.R. China
2. Department of General Surgery, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, Guangdong 510180, P.R. China
3. Department of Oncology, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, Guangdong 510180, P.R. China
4. Department of General Surgery, Zhongshan City People's Hospital Affiliated to Sun Yat‑sen University, Zhongshan, Guangdong 528403, P.R. China