Sphincter preservation therapy for distal rectal carcinoma: a review

There has been increasing interest in the use of sphincter-preserving therapy for patients with distal rectal carcinomas. The outcomes of conservative treatments for early stage rectal carcinoma appear to be comparable to that achieved with abdominoperineal resection.

Retrospective and prospective clinical series of patients with distal rectal carcinoma treated by local excision alone, local excision with postoperative adjuvant therapy, preoperative radiation followed by local excision, or radical circumferential sphincter-sparing surgeries were reviewed. The local control rates, salvage rates, and treatment complications in patients treated by these various methods were examined.

Patients with T1 distal rectal carcinoma with favorable clinical and histopathologic characteristics treated with local excision alone had a local control rate of greater than 90% in most series. Postoperative chemoradiation improved local control for those with T1 disease with unfavorable characteristics, or those with T2 disease. Most T3 patients had failure rates of greater than 30% despite adjuvant local and systemic therapy. With high dose preoperative radiation, approximately 80% of patients with locally advanced or unresectable tumors were able to undergo sphincter-preservation treatment.

Patients with favorable T1 rectal carcinoma are likely to be adequately treated with local excision alone. Patients with T1 disease with unfavorable characteristics as well as T2 patients will benefit from postoperative chemoradiation. The use of local therapy in T3 patients needs to be carefully considered because these patients are at relatively high risk for local recurrence despite adjuvant therapy. Preoperative radiation followed by either local excision or radical circumferential sphincter-sparing resections appears promising in allowing sphincter preservation in patients with locally advanced tumors.