1. Department of Colorectal Surgery, Tianjin Union Medical Center, Tianjin 300121, China
2. Department of Pathology, Tianjin Medical University General Hospital, Tianjin 300000, China
3. Department of General Surgery, Tianjin Union Medical Center, Tianjin 300121, China
4. Department of General Surgery, Nankai Hospital of Tianjin, Tianjin 300000, China