Related Experiment Video
Updated: Sep 27, 2026
Robot-assisted Total Mesorectal Excision and Lateral Pelvic Lymph Node Dissection for Locally Advanced Middle-low Rectal Cancer
Published on: February 12, 2022
Safety of laparoscopic surgery without No.253 lymph node dissection for mid and low rectal cancer (SMOOTH): study
Mingguang Zhang1, Shuohui Dong2, Haitao Zhou1
1Department of Colorectal Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Introduction:
Total mesorectal excision is currently the standard surgical treatment for rectal cancer; however, the optimal extent of proximal lymph node dissection remains a subject of ongoing debate. The No.253 lymph node is the third station node along the inferior mesenteric artery system. Whether dissection of this region is necessary for all cases of rectal cancer remains inconclusive. Our previous retrospective study demonstrated that the incidence of No.253 lymph node metastasis is extremely low in rectal patients without clinical high-risk factors. Based on these findings, we have designed a randomised controlled trial to evaluate the oncologic safety of omitting No.253 lymph node dissection in this specific patient population.
Methods And Analysis:
This is a multicentre, randomised controlled clinical trial aimed at evaluating the safety of resection for rectal cancer without No.253 lymph node dissection. A total of 1384 patients with clinically confirmed low-risk rectal cancer will be enrolled. Participants will be randomly assigned to either the No. 253 lymph node dissection group or the non-dissection group. The primary endpoint is 3-year disease-free survival rate, with a pre-specified non-inferiority margin of 7%. Secondary endpoints include the total number of lymph nodes dissected, incidence of intraoperative and 30-day postoperative complications, intraoperative blood loss, operative time, postoperative hospital stay and 3-year overall survival (OS) rate.
Ethics And Dissemination:
This study protocol has been approved by the Ethics Committee of the National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College (reference no. 23/467-4210), and has been registered at ClinicalTrials.gov (NCT06146946). The findings of this trial will be disseminated through publication in peer-reviewed international medical journals. De-identified individual participant data will not be shared.
Trial Registration Number:
NCT06146946.
