Table 1.

Inclusion, exclusion, and withdrawal criteria.

Inclusion criteria	Exclusion criteria	Withdrawal criteria
• 18 years < age < 85 years	• BMI > 30 kg/m (2)	• Intraoperative or pathological confirmation of invasion of adjacent structures or distant metastasis
• Pathological or highly suspected colorectal carcinoma	• The lower border of the tumor is located distal to the peritoneal reflection	• Non-colorectal adenocarcinoma confirmed by postoperative pathology
• Tumor located in the colon and rectum (the lower border of the tumor is above the peritoneal reflection)	• Previous gastrointestinal surgery (apart from appendicectomy)	• Requirement of emergency operation due to the change of illness state
• Clinically diagnosed cT1–4aN0–2M0 lesions according to the seventh Edition of AJCC Cancer Staging Manual	• Emergency operation due to complication caused by colorectal cancer (bleeding, perforation, or obstruction)	• Inability to undergo surgery or anesthesia due to the change of illness state
• Tumor size of ≤5 cm	• Requirement of simultaneous surgery for other disease	• Unable to complete the clinical trial due to various reasons
• Performance status ECOG 0–1	• Pregnancy or lactation	• Patient required to withdraw
• ASA class I to III	• Severe mental disease
• Informed consent	• Simultaneous or metachronous multiple cancers with disease-free survival ≤5 years

BMI, body mass index; ASA, The American Society of Anesthesiologists; ECOG, Eastern Cooperative Oncology Group.