Sphincter-Sparing Treatment for Distal Rectal Adenocarcinoma

Abstract

Background: Studies suggest that the anal sphincter can be preserved in some patients with distal rectal adenocarcinoma (DRA), but this has not been validated in any prospective multi-institutional trial.

Methods: To test the hypothesis that the anal sphincter can be preserved in some patients with DRA, the Cancer and Leukemia Group B and collaborators reviewed 177 patients who had T1/T2 adenocarcinomas ≤ 4 cm in diameter, which encompassed ≤ 40% of bowel wall circumference, and were ≤ 10 cm from the dentate line. Of the 177 patients, 59 patients who were eligible for the study had T1 adenocarcinomas and received no further treatment; 51 eligible T2 patients received external beam irradiation (5400 cGY/30 fractions 5 days/week) and 5-fluorouracil (500 mg/m² IV d1–3, d29–31) after local excision.

Results: At 48 months median follow-up, 6-year survival and failure-free survival rates of the eligible patients are 85% and 78% respectively. Three patients died of unrelated disease. Two patients were treated for second primary colorectal tumors; both remain disease free (NED). Another eight patients died of disease, four with distant recurrence only. One T1 patient is alive with distant disease. Two T1 and seven T2 patients experienced isolated local recurrences; all underwent salvage abdominoperineal resection (APR). After APR, one T1 and four of seven T2 patients were NED at the time of last visit (2–7 years). One T1 patient died of local and distant disease. Three of seven T2 patients died with distant disease.

Conclusions: We conclude that sphincter preservation can be achieved with excellent cancer control without initial sacrifice of anal function in most patients. After local recurrence, salvage resection appears effective, but longer follow-up time of local and distant disease-free survival is advised before extrapolation to patients with T3 primaries.