Transanal Total Mesorectal Excision vs Robotic Total Mesorectal Excision (TaLaR03)

A Prospective, Randomized, Parallel-Controlled, Superiority Clinical Study Comparing Transanal Total Mesorectal Excision (taTME) and Robot-Assisted Total Mesorectal Excision (RTME) in the Treatment of Low Rectal Cancer

TME remains standard treatment for rectal cancer. Both Robotic TME and taTME are innovative surgical techniques with potential advantages in low rectal cancer. To date, no clinical studies have directly compared the conversion and complication rates between taTME and RTME in this population. Therefore, the investigators propose to conduct a prospective, randomized, parallel-controlled clinical trial comparing taTME with RTME for low rectal cancer, aiming to provide high-level evidence for surgical decision-making and benefit more patients.

Study Overview

• Status: Recruiting
• Conditions: Rectal Cancer Patients; Robotic Assisted Intervention
• Intervention / Treatment: Procedure: robotic surgery vs transanal total mesorectal excsion

Detailed Description

Both RTME and taTME are innovative surgical techniques with potential advantages in low rectal cancer. Intraoperative conversion rate is a key safety metric. In low rectal cancer, changes in surgical approach not only affect resection outcomes but also sphincter preservation.To date, no clinical studies have directly compared the conversion and complication rates between taTME and RTME in this population. Therefore, the investigators propose to conduct a prospective, randomized, parallel-controlled clinical trial comparing taTME with RTME for low rectal cancer, aiming to provide high-level evidence for surgical decision-making and benefit more patients. The primary indicator in this study is intraoperative conversion rate. Definition in each group as follows: During transanal total mesorectal excision (taTME), if the procedure cannot be completed due to difficulty in transanal operation, conversion to open abdominal surgery is required to complete TME resection, allowing better operative access, organ preservation, and tumor clearance. During robot-assisted total mesorectal excision (rTME), if the transabdominal approach fails to achieve bowel transection or digestive reconstruction, conversion to transanal or open abdominal surgery is required to complete the procedure, ensuring operability, organ preservation, and tumor clearance.

• Study Type: Interventional
• Enrollment (Estimated): 216
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Liang Kang, MD; Phone Number: +8613602886833; Email: kangl@mail.sysu.edu.cn
• Study Contact Backup: Name: Ling Shuang Luo, MD; Phone Number: +8613751756175; Email: kangl@mail.sysu.edu.cn

Study Locations

• China
  • Guangdong
    • Guangzhou, Guangdong, China, 510655
      • Recruiting
      • The sixth affiliated hospital of Sun Yat-Sen University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:Newly diagnosed patients aged 18-75 years. Pathologically confirmed adenocarcinoma (tubular, papillary, mucinous, or signet-ring). Tumor ≤7 cm from anal verge (MRI or DRE). Clinical stage T1-T3, N+, M0 (AJCC 8th ed.), suitable for sphincter-preserving TME. ASA score I-III.

ECOG performance status 0-1. Informed consent obtained.

- Exclusion Criteria: Synchronous/metachronous colorectal cancers, local recurrence, or distant metastases. Bowel obstruction, perforation, bleeding requiring emergency surgery. Involvement of sphincter or adjacent organs requiring Inter-sphincter Resection (ISR). Poor preoperative anal function/incontinence. IBD or familial adenomatous polyposis (FAP).

Pregnancy or lactation. Severe psychiatric illness. Other malignancies within 5 years. Severe comorbidities or infections making surgery intolerable. Judged unsuitable by investigator.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: robotic TME; For patients with low rectal cancer, the da Vinci multi-arm robotic system is used to perform total mesorectal excision (TME). The procedure includes vascular ligation, mesenteric mobilization, distal bowel transection beyond the tumor, and anastomosis, all completed transabdominally with robotic assistance.	Procedure: robotic surgery vs transanal total mesorectal excsion; This study is designed to investigate the safety and superiority of transanal total mesorectal excision (taTME) in the treatment of rectal cancer compared with robot-assisted total mesorectal excision (rTME)
Experimental: taTME; For patients with low rectal cancer, a combined transanal and transabdominal approach is used to complete the total mesorectal excision (TME). A purse-string suture is placed approximately 1 cm below the distal tumor margin, followed by insertion of a single-port device. The mesorectum is then mobilized from bottom to top. Vascular ligation is performed laparoscopically via the abdominal approach. The two teams (transanal and transabdominal) meet near the peritoneal reflection.	Procedure: robotic surgery vs transanal total mesorectal excsion; This study is designed to investigate the safety and superiority of transanal total mesorectal excision (taTME) in the treatment of rectal cancer compared with robot-assisted total mesorectal excision (rTME)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intraoperative Conversion Rate	During transanal total mesorectal excision (TaTME), if the procedure cannot be completed due to difficulty in transanal operation, conversion to open abdominal surgery is required to complete TME resection, allowing better operative access, organ preservation, and tumor clearance. During robot-assisted total mesorectal excision (rTME), if the transabdominal approach fails to achieve bowel transection or digestive reconstruction, conversion to transanal or open abdominal surgery is required to complete the procedure, ensuring operability, organ preservation, and tumor clearance.	at the end of operation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
3-year disease-free survival (DFS)	3-Year DFS (Disease-Free Survival) refers to the proportion of patients who remain alive and free from any signs or recurrence of the disease for three years following surgical removal of the primary tumor.	three years after the operation
3-Year OS	3-Year OS (Overall Survival) refers to the percentage of patients who remain alive for three years following a surgical procedure, regardless of the cause of death or the status of the disease. The survival time is typically calculated from the date of surgery to the date of death from any cause. Patients who are alive at the three-year mark-whether they are disease-free, have experienced a recurrence, or are receiving other treatments-are counted as survivors	3 years after the operation
operative time	Operative time refers to the total duration measured from the initial surgical incision to the completion of wound closure. It typically includes all intraoperative procedures, such as dissection, resection (e.g., tumor removal), reconstruction, hemostasis, and placement of drains or implants, but excludes anesthesia induction, positioning, prepping, draping, and recovery room time	1 day after the operation

Collaborators and Investigators

• Sponsor: Sun Yat-sen University
• Investigators: Principal Investigator: Liang Kang, Sixth Affiliated Hospital, Sun Yat-sen University

Publications and helpful links

General Publications

• Liu H, Zeng Z, Zhang H, Wu M, Ma D, Wang Q, Xie M, Xu Q, Ouyang J, Xiao Y, Song Y, Feng B, Xu Q, Wang Y, Zhang Y, Hao Y, Luo S, Zhang X, Yang Z, Peng J, Wu X, Ren D, Huang M, Lan P, Tong W, Ren M, Wang J, Kang L; Chinese Transanal Endoscopic Surgery Collaborative (CTESC) Group. Morbidity, Mortality, and Pathologic Outcomes of Transanal Versus Laparoscopic Total Mesorectal Excision for Rectal Cancer Short-term Outcomes From a Multicenter Randomized Controlled Trial. Ann Surg. 2023 Jan 1;277(1):1-6. doi: 10.1097/SLA.0000000000005523. Epub 2022 Jul 11.
• Jiang W, Xu J, Cui M, Qiu H, Wang Z, Kang L, Deng H, Chen W, Zhang Q, Du X, Yang C, Guo Y, Zhong M, Ye K, You J, Xu D, Li X, Xiong Z, Tao K, Ding K, Zang W, Feng Y, Pan Z, Wu A, Huang F, Huang Y, Wei Y, Su X, Chi P; LASRE trial investigators. Laparoscopy-assisted versus open surgery for low rectal cancer (LASRE): 3-year survival outcomes of a multicentre, randomised, controlled, non-inferiority trial. Lancet Gastroenterol Hepatol. 2025 Jan;10(1):34-43. doi: 10.1016/S2468-1253(24)00273-5. Epub 2024 Nov 8.
• Feng Q, Yuan W, Li T, Tang B, Jia B, Zhou Y, Zhang W, Zhao R, Zhang C, Cheng L, Zhang X, Liang F, He G, Wei Y, Xu J; REAL Study Group. Robotic versus laparoscopic surgery for middle and low rectal cancer (REAL): short-term outcomes of a multicentre randomised controlled trial. Lancet Gastroenterol Hepatol. 2022 Nov;7(11):991-1004. doi: 10.1016/S2468-1253(22)00248-5. Epub 2022 Sep 8.
• Feng Q, Yuan W, Li T, Tang B, Jia B, Zhou Y, Zhang W, Zhao R, Zhang C, Cheng L, Zhang X, Wei Y, Liang F, He G, Xu J; REAL Study Group. Robotic vs Laparoscopic Surgery for Middle and Low Rectal Cancer: The REAL Randomized Clinical Trial. JAMA. 2025 Jul 8;334(2):136-148. doi: 10.1001/jama.2025.8123.
• Zeng Z, Luo S, Zhang H, Wu M, Ma D, Wang Q, Xie M, Xu Q, Ouyang J, Xiao Y, Song Y, Feng B, Xu Q, Wang Y, Zhang Y, Shi L, Ling L, Zhang X, Huang L, Yang Z, Peng J, Wu X, Ren D, Huang M, Lan P, Wang J, Tong W, Ren M, Liu H, Kang L; Chinese Transanal Endoscopic Surgery Collaborative (CTESC) Group. Transanal vs Laparoscopic Total Mesorectal Excision and 3-Year Disease-Free Survival in Rectal Cancer: The TaLaR Randomized Clinical Trial. JAMA. 2025 Mar 4;333(9):774-783. doi: 10.1001/jama.2024.24276.

Study record dates

Study Major Dates

• Study Start (Actual): June 30, 2025
• Primary Completion (Estimated): April 28, 2027
• Study Completion (Estimated): April 28, 2029

Study Registration Dates

• First Submitted: May 24, 2026
• First Submitted That Met QC Criteria: June 10, 2026
• First Posted (Actual): June 16, 2026

Study Record Updates

• Last Update Posted (Actual): June 16, 2026
• Last Update Submitted That Met QC Criteria: June 10, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: rectal cancer; taTME; robotic TME
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Intestinal Diseases; Gastrointestinal Neoplasms; Digestive System Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Colorectal Neoplasms; Intestinal Neoplasms; Rectal Diseases; Rectal Neoplasms
• Other Study ID Numbers: 2025ZSLYEC-104

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No