1. The Oncology Department, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450014, P.R. China
2. Department of Digestive Medicine, Hospital of Traditional Chinese Medicine of Liaocheng City, Liaocheng, Shandong 252000, P.R. China
3. Department of Gastrointestinal Surgery, Liaocheng People's Hospital, Liaocheng, Shandong 252000, P.R. China