Transanal Local Excision of Rectal Cancer after Neoadjuvant Chemoradiation: Is There a Place for It or Should Be Avoided at All Costs?

Tumor response to neoadjuvant chemoradiation (nCRT) with tumor downsizing and downstaging has significantly impacted the number of patients considered to be appropriate candidates for transanal local excision (TLE). Some patients may harbor small residual lesions, restricted to the bowel wall. These patients, who exhibit major response ("near-complete") by digital rectal examination, endoscopic assessment, and radiological assessment may be considered for this approach. Although TLE is associated with minimal postoperative morbidity, a few clinical consequences and oncological outcomes must be evaluated in advance and with caution. In the setting of nCRT, a higher risk for clinically relevant wound dehiscences leading to a considerable risk for readmission for pain management has been observed. Worse anorectal function (still better than after total mesorectal excision [TME]), worsening in the quality of TME specimen, and higher rates of abdominal resections (in cases requiring completion TME) have been reported. The exuberant scar observed in the area of TLE also represents a challenging finding during follow-up of these patients. Local excision should be probably restricted for patients with primary tumors located at or below the level of the anorectal ring (magnetic resonance defined). These patients are otherwise candidates for abdominal perineal resections or ultra-low anterior resections with coloanal anastomosis frequently requiring definitive stomas or considerably poor anorectal function.