Inclusion Criteria:  1. pathologically confirmed adenocarcinoma of colon 2. The tumor is located in the transverse colon (including hepatic or splenic flexure); 3. One of the following procedures was performed: transverse colectomy, right hemicolectomy, enlarged right hemicolectomy, left colectomy, enlarged left colectomy; 4. Laparoscopic surgery (laparoscopy-assisted surgery or complete laparoscopic surgery) from August 2019 to July 2021; 5. Radical resection (R0) was accomplished;  Exclusion Criteria:  1. Simultaneous multiple colorectal cancer; 2. history of colorectal surgery (except endoscopic surgery); 3. robot-assisted surgery; 4. palliative resection (non-R0 resection) or palliative bypass; 5. the approach of anastomosis could not be determined from the documents; 6. the length of resection margin was not recorded in pathological report;