1. Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215000, P.R. China
2. Department of Medical Oncology, Sichuan Cancer Hospital, Medical School of University of Electronic Science and Technology of China, Chengdu, Sichuan 610000, P.R. China
3. Department of Thoracic Surgery, Sichuan Cancer Hospital, Medical School of University of Electronic Science and Technology of China, Chengdu, Sichuan 610000, P.R. China