Resection Margin of Transverse Colon Cancer With Extracorporeal Versus Intracorporeal Anastomosis

13 participating centers are as follows: Ruijin Hospital, Shanghai Jiaotong University School of Medicine；Zhejiang University Medical College Affiliated Sir Run Shaw Hospital；Zhongshan Hospital Affiliated to Fudan University；Renji Hospital Affiliated to Medical College of Shanghai Jiaotong University; Jiangsu Provincial People's Hospital; Xiangya Hospital of Central South University; The First Affiliated Hospital of Chongqing Medical University; The first hospital of Jilin University; Beijing Friendship Hospital Affiliated to Capital Medical University; Tangdu Hospital; Tongji Hospital Affiliated to Tongji Medical College of Huazhong University of science and technology; Cancer Hospital of Chinese Academy of Medical Sciences; Henan Provincial People's Hospital

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;