Neoadjuvant therapy and transanal endoscopic surgery in T2-T3 superficial, N0, M0 rectal tumors. Local recurrence, complete clinical and pathological response

Introduction: The association of preoperative chemoradiotherapy and transanal endoscopic surgery in T2 and superficial T3 rectal cancers presents promising results in selected patients. The main objective is to evaluate the long-term loco-regional and systemic recurrence and, as secondary objectives, to provide results of postoperative morbidity and the correlation between complete clinical and pathological response.

Methods: This is a retrospective observational study including a consecutive series of patients with T2-T3 superficial rectal cancer, N0, M0 who refused radical surgery (2008-2016). The treatment consisted of preoperative chemotherapy (5-fluorouracil or capecitabine) combined with radiotherapy (50, 4Gy) and transanal endoscopic surgery after 8weeks. Preoperative, surgical, pathological and long-term oncologic results were analyzed.

Results: Twenty-four patients were included in the study. Two of them required rescue radical surgery for unfavorable pathological results. A local recurrence (4.5%) was observed and 2patients presented systemic recurrence (9%), with a median follow-up of 45 months. A complete clinical tumor response was achieved in 12 patients (50%), and complete pathological tumor response in 9 patients (37.5%). Postoperative complications were observed in 5 patients (20.8%), and they were mild except one. There was no postoperative mortality.

Conclusions: In this stage of rectal cancer, our results seem to support this strategy, mainly when a complete pathological response is achieved. The complete clinical tumor response does not coincide with the pathological tumor response. Randomized prospective studies should be performed to standardize this treatment.