Microcirugía endoscópica transanal y cáncer de recto: realidad o quimera

Transanal endoscopic surgery with total wall excision is required with rectal adenomas due to the high frequency of adenocarcinoma

BACKGROUND

Colorectal adenomatous polyps are considered premalignant lesions, although a high percentage are already malignant at the time of their removal. Full-thickness excision in patients with adenoma detected in preoperative biopsy enables much more accurate pathology examination and has shown that local surgery is appropriate for T1 adenocarcinoma.

OBJECTIVE

To determine whether full-thickness excision during transanal endoscopic surgery is the treatment of choice for rectal adenoma, and to identify possible predictors of invasive adenocarcinoma associated with this type of lesion.

DESIGN

Prospective, observational study.

SETTING

The study was conducted at a university teaching hospital.

PATIENTS

All patients scheduled for transanal endoscopic surgery after detection of adenoma in a preoperative biopsy between June 2004 and February 2013 entered the study.

MAIN OUTCOME MEASURES

The principal variable was the presence of invasive adenocarcinoma in the pathology study. Other study variables were the epidemiological variables sex and age; the clinical variables tumor size, number of quadrants affected, distance from the anal verge, and tumor location; and the morphological variables tumor aspect, degree of dysplasia, preoperative biopsy (tubulo-villous), endorectal ultrasound, and pelvic MRI stage. Variables found to be related to the risk of malignancy in rectal adenomas were evaluated using univariate and multivariate analysis.

RESULTS

Of 471 patients who underwent surgery, 277 had a preoperative diagnosis of adenoma. Final pathology studies showed 52 (18.8%) invasive adenocarcinomas, among which 27 were pT1 (52%), 16 pT2 (30.7%), and 9 pT3 (17.3%). Factors predictive of invasive adenocarcinoma were sessile morphology (OR 3.2, 95%CI 1.4-7.1), high-grade dysplasia (OR 2.3, 95%CI 1.2-4.8), and endorectal ultrasound stage uT2-T3 (OR 3.8, 95%CI 1.6-9).

LIMITATIONS

The limitations are derived from the observational design.

CONCLUSIONS

In this sample, half of the adenocarcinomas from adenomas were T1 adenocarcinomas. Because a high proportion of rectal adenomas are, in fact, invasive adenocarcinomas, full-thickness excision is appropriate.

[Site of local surgery in adenocarcinoma of the rectum T2N0M0]

INTRODUCTION

The local exeresis adenocarcinoma of the rectum T(2)N(0)M(0) (ADC-T2), using transanal endoscopic microsurgery (TEM), has the benefit of achieving lower morbidity with a better quality of life. However, local occurrence of the local exeresis is greater than 20%, which is unacceptable these days.

PATIENTS AND METHODS

Prospective, observational follow up study. The tumours committee agreed that those ADC-T2 patients could have the following treatments: total mesorectal excision (TME), simple TEM, TEM with postoperative chemo- and radiotherapy (Ct-Rt), preoperative Ct-Rt with subsequent TEM and radical surgical rescue (TME) within at least 4 weeks.

RESULTS

Of the 146 patients operated on using TEM, 75 had adenocarcinomas, 59 adenomas, 6 scarring wounds, 5 carcinoids and 1 GIST. Of the adenocarcinomas 22 were ADC-T2. Follow up: median of 16 months (range, 3-32 months). The overall local recurrence was 18% (4/22). According to the treatment strategy the local occurrence was: TEM as the only procedure, 20% (2/10). Radical surgical rescue was performed on 3 patients after TEM, with no local or systemic recurrences. TEM with Qt-Rt after surgery was performed on 6 patients, with a local recurrence of 33% (2/6). Ct-Rt and subsequent TEM in 3 patients, with no local or systemic recurrences.

CONCLUSIONS

Treatment of ADC-T2 using simple TEM is not effective. The combination of Ct-Rt after TEM, does not improve the results of TME. It is possible to rescue those patients without changing the overall survival. Preoperative Ct-Rt and TEM appears to be the approach that obtains a clinical and histological response, although a response is needed by clinical trials.