Randomized, multicenter, phase III trial to compare the short and long outcomes of laparoscopic CME with open CME in treating patients with locally advanced colon cancer.

Laparoscopic complete mesocolic excision (CME) in treating colon cancer has been reported to be feasible and safe and holds many advantages when compared with traditional open surgery, such as reducing preoperative blood loss, alleviating postoperative pain and reducing complications and length of hospital stay. Whether laparoscopic CME could achieve an equivalent oncological outcome, especially for locally advanced malignancy, is still being discussed.

The purpose of this study is to determine the short and long outcomes of open and laparoscopic CME for locally advanced colon cancer patients. The primary endpoint is the 5-year disease-free survival rate. Secondary endpoints include completeness of mesocolon, morbidity and mortality, local recurrence, overall survival, quality of life et al.

In this study, eligible patient will be randomly allocated to receive either open or laparoscopic CME surgery. Randomization will be performed centrally and be stratified for age, gender, T-stage, tumor location. Patients will be randomized in a 2:1 ratio, in favor of the laparoscopic CME.

The extent of resection according to CME principle is identical for both arms. CME involves the removal of the afflicted colon and its accessory lymphvascular supply at their origins by resecting the colon and mesocolon in an intact envelope of visceral peritoneum and mesenteric fascia. Type of anastomosis, location of auxiliary incision and drainage of surgical field are up to the discretion of the surgeon. In laparoscopic surgery, a "medial-to-lateral" approach and a no-touch isolation are required .

Intraoperative pictures were taken at various stages, as were photographs of the postoperative specimen, which will be assessed by a third-party expert to qualify the surgery.

The baseline demographics and conditions as well as the perioperative and postoperative outcomes will be recorded through a prior designed format.

Our study is expected to last seven years, of which two years for recruiting patients, five years for follow-up. Patients are followed up every 3 months for 2 year, every 6 months for 3 years postoperatively.

Inclusion Criteria:

• Patients suitable for curative surgery over 18 years old;
• American Society of Anesthesiologists(ASA) grade I-III;
• Pathological diagnosis of adenocarcinoma;
• Tumor located between the cecum and sigmoid colon;
• Enhanced CT scan of chest, abdominal and pelvic cavity: preoperative assessment of tumor stage is T3-T4 N0 or T any N+ (according to the National Comprehensive Cancer Network(NCCN) clinical practice guidelines in oncology: colon cancer version 2.2015);there is no distant metastasis;
• Informed consent;
• No preoperative chemoradiotherapy;
• No history of familial adenomatous polyposis, ulcerative colitis or Crohn's disease.

Exclusion Criteria:

• Pregnant patient;

• History of psychiatric disease;

• Use of systemic steroids;

• Conversion to laparotomy;

• Simultaneous or simultaneous multiple primary colorectal cancer;

• Preoperative imaging examination results show:

  1. Tumor involves the surrounding organs and combined organ resection need to be done;
  2. distant metastasis;
  3. unable to perform R0 resection;

• Postoperative pathology of T1-T2 N0;

• History of any other malignant tumor in recent 5 years;

• Patients need emergency operation: mechanic ileus, perforation.

• Not suitable for laparoscopic surgery (i.e., extensive adhesion caused by abdominal surgery, not suitable for artificial pneumoperitoneum, etc).