Transanal endoscopic microsurgery for 135 patients with small nonadvanced low rectal cancer (iT1-iT2, iN0): short- and long-term results

Local excision of rectal cancer as an alternative to radical resection for patients with small nonadvanced low rectal cancer (SNALRC) (iT1-iT2, iN0) is debated. This study aimed to analyze the short- and long-term results for a series of 135 patients with SNALRC who underwent local excision by transanal endoscopic microsurgery (TEM). According to the study protocol, 135 patients classified by endorectal ultrasound, magnetic resonance imaging (MRI), and computed tomography (CT) imaging as having iT1 iN0 iM0 (n = 51) or iT2 iN0 iM0 (n = 84) low rectal cancer were enrolled in the study. All the patients with iT2 rectal cancer underwent neoadjuvant therapy. The definitive histologic findings showed 24 pT0 patients (17.8%), 66 pT1 patients (48.8%), and 45 pT2 patients (33.4%). Minor complications were observed in 12 patients (8.8%) and major complications in 2 patients (1.5%). During a median follow-up period of 97 months (range, 55-139 months), local recurrences occurred for four patients and distant metastases for two patients. The patients who experienced a recurrence had been preoperatively staged as iT2 and were low or nonresponders to neoadjuvant treatment (ypT2). At the end of the follow-up period, the disease-free survival rates were 100% for the iT1 patients and 93% for the iT2 patients The long-term results for adequate local excision by TEM with or without neoadjuvant radiochemotherapy in the treatment of SNALRC based on the current study protocol are not inferior to those reported in the literature for radical surgery with total mesorectal excision (TME).