1. Department of Gastrointestinal Medical Oncology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, People's Republic of China
2. Department of Gastrointestinal Medical Oncology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, People\'s Republic of China
3. Department of Colorectal Surgery, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, People\'s Republic of China
4. Department of General Surgery, the First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, People\'s Republic of China