Total Mesorectal Excision vs. Transanal Endoscopic Microsurgery Followed by Radiotherapy for T2N0M0 Distal Rectal Cancer: A Multicenter Randomized Trial.

[INTRODUCTION] Transanal endoscopic microsurgery (TEM) is an organ-preserving treatment alternative for patients with early rectal cancer. However, TEM alone is associated with greater risk of local recurrence and inferior survival in comparison with total meso-rectal excision (TME). As an important adjuvant therapy, radiotherapy can effectively reduce the local recurrence rate of rectal cancer. This study aimed to investigate whether TEM followed by radiotherapy can be a valid alternative to TME in T2N0M0 distal rectal cancer treatment.

[METHODS] We plan to recruit 168 participants meeting established inclusion criteria. Following informed consent, participants will randomly receive treatment protocols of TEM followed by radiotherapy (a total dose of 45-50.4 Gy given in 25-28 factions) or TME. Depending on post-operative pathology, the participants will receive either long-term follow-up or further treatment. The primary endpoint of this trial is 3-year local recurrence rate. The secondary end points include 3-year disease-free survival rate, 3-year overall survival rate, 3-year mortality rate, post-operative quality of life, post-operative safety index, intraoperative evaluation index and post-operative short-term evaluation index.

[DISCUSSION] This trial is the first prospective randomized trial to investigate the rectum preserving treatment by using transanal local excision followed by radiotherapy.

[CLINICAL TRIAL REGISTRATION] The trial was prospectively registered at ClinicalTrials.gov NCT04098471 on September 20, 2019.