1. Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hebei 430022, P.R. China
2. Division of Gastroenterology, Liyuan Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hebei 430077, P.R. China
3. Institute of Pathology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hebei 430022, P.R. China
4. Department of Radiation Oncology, Hubei Cancer Hospital, Wuhan, Hebei 430070, P.R. China