Transanal approaches to rectal neoplasia

Local excision is a well-tolerated, low risk, curative oncologic operative approach for highly selected early-stage rectal cancers. As with any cancer treatment, cure is balanced with morbidity and quality of life. In this respect, the best management for a patient with an early rectal cancer highlights the clinical dilemma balancing concerns for over- versus under-treatment. That is to say, radical resection may be oncologically equivalent to local excision for true early stage cancer, yet, results in much greater morbidity, including the possibility of a permanent colostomy. Alternatively, local excision of a presumed early rectal cancer may be oncologically inferior to mesorectal excision, potentially compromising the cancer outcome dramatically. Navigating between these two surgical extremes requires incorporation of multiple critical clinico-pathologic variables, including accurate clinical staging, precise tumor localization, careful histologic assessment to recognize higher risk features, and patient fitness and preference.

While pelvic failure following local excision is generally more common than after radical resection, the gap between disease-free and overall survival is not quite as wide, particularly among lower-risk pT1Nx cancers in patients following LE. The lack of histologic lymph node staging and reliance on imperfect imaging to risk estimate micrometastatic mesorectal nodal disease, the higher morbidity associated with completion mesorectal excision pursued for a histologically higher-risk early rectal cancer, and the greater risk of an extended resection at salvage operation for locoregional recurrence collectively emphasize the degree of caution when considering a more limited excisional operative approach.