Conservative management of rectal carcinoma: the efficacy of a multimodality approach.

The goals of the conservative management of adenocarcinoma of the distal rectum are to preserve rectal sphincter function and achieve excellent local tumor control. Multimodality therapy for more advanced disease suggests that these goals will be met by conservative surgery combined with radiation therapy and chemotherapy. Over 100 patients with T0-3 N0-1 lesions have been treated in prospective single institution trials with either local excision or anterior resection with coloanal anastomosis, usually combined with chemotherapy and radiotherapy. The typical criteria for local excision have been for lesions to be 4.0 cm or less, mobile, and not poorly differentiated or mucinous. Patients with larger or more advanced lesions may undergo anterior resection with coloanal anastomosis. Following resection, radiotherapy is delivered to the pelvis and tumor bed often with concomitant chemotherapy. The overall rate of local failure in the trials in which local excision is performed with postoperative chemoradiotherapy is 3% for T1 lesions, 5% for T2 lesions, and 30% for T3 lesions with a median follow-up of at least 25 months. Local failure in patients with a coloanal anastomosis is 9% overall. Salvage was successful in about half of the patients who failed locally. Importantly, nearly all patients remained continent. These institutional studies show that sphincter preservation can be used in patients who are objectively selected for this procedure. However, before this multimodality approach may be considered standard therapy the rate of local control must be confirmed in a large, Phase II, multicenter, prospective trial such as that now underway in many of the cooperative groups.