Preoperative Chemoradiotherapy and Transanal Endoscopic Microsurgery Versus Total Mesorectal Excision in T2-T3s N0, M0 Rectal Cancer

Prospective Randomized Clinical Trial for no Inferiority With Preoperative Chemoradiotherapy and Transanal Endoscopic Microsurgery (TEM) Versus Total Mesorectal Excision in T2-T3s N0, M0 Rectal Cancer

The standard treatment of rectal adenocarcinoma is total mesorectal excision (TME). The technique involves a low anterior rectal or colo-anal resection, very often associated with a protective stoma or abdominal-perineal resection with permanent colostomy. Transanal endoscopic microsurgery (TEM) allows access to tumors up to 20 cm from the anal margin, with minimal postoperative morbidity and mortality. Recent studies of T1 rectal adenocarcinomas consider TEM to be the technique of choice. However the treatment of T2 rectal cancers remains controversial. Chemotherapy and radiotherapy (CT/RT) has achieved a concomitant reduction in local recurrence and an increase in survival.

Hypothesis: Patients with rectal adenocarcinoma less than 10 cm from the anal margin and up to 4 cm in size, staged after endorectal ultrasound and MRI as T2 or superficial T3 N0-M0-N0-M0, who underwent surgery after preoperative local chemoradiotherapy (TEM), achieve effective results in terms of local recurrence similar to radical surgery (TME).

OBJECTIVES:

Primary: To compare the results of local recurrence at 2 years in patients treated with preoperative chemoradiotherapy and TEM and in patients treated with conventional radical surgery (TME).

Secondary: To analyse the 3-year survival results in patients treated with CT/RT.

Methodology: Multicenter clinical trial in a calculated sample of 173 patients.

Inclusion Criteria:

1. Rectal adenocarcinomas located 10 cm or less from the inferior anal verge measured using a rigid rectoscope at the time of the EUS.
2. Preoperative staging by EUS and pelvic MRI of T2 or T3 superficial, N0. In case of disparity, the higher staging is considered as the definitive diagnosis.
3. Tumours equal to or less than 4 cm of diameter maximum measured using colonoscopy, EUS or MRI. We use the highest score on both scores.
4. ASA score III or less.
5. Absence of distance metastasis as shown on abdominal CT.

Exclusion Criteria:

1. Preoperative staging by EUS or pelvic MRI of T1, deep T3, T4 or N1.
2. Presence of distance metastasis.
3. Synchrony with other colorectal adenocarcinomas.
4. Undifferentiated rectal adenocarcinomas or with presence of poor prognosis factors in preoperative biopsy.
5. Patients with intolerance of preoperative chemotherapy or radiotherapy.
6. Refusal to sign informed consent to enter the study.