Adequacy of 1-cm distal margin after restorative rectal cancer resection with sharp mesorectal excision and preoperative combined-modality therapy.

BACKGROUND: Preoperative combined-modality therapy (CMT) for rectal cancer allows a sphincter-sparing procedure in some individuals who would otherwise require an abdominoperineal resection. To further define the subset of rectal cancer patients suitable for this approach, we determined the adequacy of a distal margin of < or = 1 cm in patients with locally advanced rectal cancer requiring preoperative CMT.
METHODS: Ninety-four consecutive patients, status post curative low anterior resection for rectal cancer after preoperative CMT, were identified from the prospective Colorectal Service Database. Distal margin length, tumor grade, tumor-node-metastasis stage, presence of lymphovascular and perineural invasion, and tumor distance from the anal verge were examined for their effect on recurrence and survival. Median follow-up was 44 months.
RESULTS: Distal margin length ranged from.1 to 9.5 cm (median, 2.0 cm) and did not correlate with local recurrence (hazard ratio, 1.1; P =.34) or recurrence-free survival (hazard ratio, 1.1; P =.29) by univariate analysis. Kaplan-Meier estimates of recurrence-free survival and local recurrence at 3 years for the < or = 1 cm versus >1 cm and the < ore = 2 cm versus > 2 cm groups were not significantly different. Groups were well matched for other clinicopathologic variables.
CONCLUSIONS: Our data suggest that for patients with locally advanced rectal cancer undergoing resection and preoperative CMT, distal margins < or = 1 cm do not seem to compromise oncological outcome.