Multicenter Phase II Study of Transanal Total Mesorectal Excision (taTME) with Laparoscopic Assistance for Rectal Cancer
Radical rectal cancer resection, namely total mesorectal excision (TME), is the cornerstone of the treatment of resectable rectal cancer. In combination with chemotherapy and radiation treatment (CRT), complete TME with negative resection margins is associated with sustained local and systemic control even in locally advanced disease. Over the last 2 decades, laparoscopic and robotic techniques have been increasingly adopted due to reduced surgical trauma and faster patient recovery. Yet, both approaches are associated with equivalent postoperative morbidity and disturbances in sexual, urinary and defecatory function relative to open TME. Furthermore, laparoscopic and robotic TME remain associated with substantial conversion rates and variable rates of TME completeness as a result of the procedural difficulties reaching the low rectum from the abdominal approach. Transanal TME (taTME) with laparoscopic assistance was developed to facilitate completion of TME using a primary transanal endoscopic approach. Transanal TME uses a 'bottom-up approach' to overcome the technical difficulties of low pelvic dissection using an abdominal approach. Published results from single-center taTME series and an international registry suggest the short-term procedural and oncologic safety of this approach in resectable rectal cancer. No multicenter phase II study has yet been conducted to validate the procedural safety, functional outcomes or long-term oncologic outcomes of this approach.
Study Design: This is a 5-year phase II multicenter single-arm study to evaluate the safety and efficacy of low anterior resection (LAR) with taTME using laparoscopic or robotic assistance in 100 eligible subjects with resectable rectal cancer.
Hypothesis: taTME is non-inferior to standard LAR with respect to the quality of the TME achieved.
• New diagnosis of histologically confirmed adenocarcinoma of the rectum
• Clinical stage cT1 (high-risk), T2, or T3, cN0, N1, N2 on staging pelvic MRI
• Negative predicted CRM on staging pelvic MRI
• No evidence of metastasis on CT scans of the chest, abdomen and pelvis
• Rectal cancer located within 10 cm from the anal verge based on proctoscopy and digital rectal examination (DRE)
• Complete preoperative colonoscopy demonstrating no synchronous colon cancer
• Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2 (Karnofsky ≥ 60%)
• Eligible to undergo laparoscopic or robotic LAR with or without a temporary diverting stoma, based on multidisciplinary tumor board consensus.
• cT4 on staging pelvic MRI
• >12 weeks delay between completion of neoadjuvant CRT and planned study procedure
• Severely symptomatic rectal tumors
• Tumors invading into the internal anal sphincter muscle based on DRE and pelvic MRI
• Fecal incontinence at baseline
• Prior history of rectal resection
• Prior history of colorectal cancer
• History of inflammatory bowel disease
• Uncontrolled concurrent illness
Mark Whiteford, M.D.
Icahn School of Medicine at Mount Sinai