Abstract Purpose For clinical (c) T1N0M0 rectal adenocarcinoma without adverse pathological features, local excision by transanal endoscopic surgery (TEM) is standard; however, contemporary series still report local recurrence (LR) rates of 15–20%. Preoperative unfavorable histopathologic features cannot reliably identify high-risk pT1 disease, and both completion total mesorectal excision (TME) and salvage TME for LR carry relevant morbidity and functional impairment. Building on our prior phase III trial in T2–T3abN0M0 (TAUTEM study), showing that preoperative chemoradiotherapy (CRT) followed by TEM achieved a 7.4% LR with improved postoperative outcomes, we hypothesize that CRT + TEM will increase rectal preservation in cT1N0M0 without compromising oncologic safety or quality of life. The TAUTEM-T1 trial tests this hypothesis. Methods Multicenter, prospective, randomized, controlled, phase III superiority trial. Adults with biopsy-proven rectal low or moderate grade adenocarcinoma ≤ 4 cm, located < 10 cm from the anal verge, staged as cT1N0M0, are randomized (1:1) to: CRT (long-course radiotherapy with concurrent capecitabine) followed by TEM at week 10, or TEM alone. The primary endpoint is rectal preservation at 3 years. Secondary endpoints include postoperative morbidity/mortality, CRT-related adverse events, quality of life and anorectal function, and long-term oncologic outcomes (local/distant recurrence, overall and disease-free survival). Planned sample size: 106 patients. Results This manuscript describes the rationale and design of the TAUTEM-T1 randomized trial. Conclusion TAUTEM-T1 will assess whether preoperative CRT followed by TEM increases rectal preservation in cT1N0M0 rectal cancer without compromising oncologic safety, quality of life, or bowel function. Trial registration ClinicalTrials.gov, NCT06450574.
Serra-Aracil et al. (Thu,) studied this question.