1. Department of Gastroenterology, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450007, P.R. China
2. Department of Spleen and Stomach, Xi'an Traditional Chinese Medicine Hospital, Xi'an, Shanxi 710021, P.R. China
3. Department of Abdominal Radiotherapy, Fujian Province Cancer Hospital, Fuzhou, Fujian 350014, P.R. China
4. Department of Pathology, Fujian Province Cancer Hospital, Fuzhou, Fujian 350014, P.R. China