Oncologic outcomes in rectal cancer patients with a ≤1-cm distal resection margin.

Abstract

Recently, common application of sphincter-saving resection in rectal cancer has led to acceptance of a 1-cm distal resection margin (DRM). The aim of this study was to evaluate oncologic outcomes of a DRM ≤1cm in sphincter-saving resection for rectal cancer. The outcomes of a DRM ≤0.5cm was also evaluated. We reviewed prospectively collected data from 415 patients who underwent sphincter-saving resection for mid and low rectal cancer between September 2006 and December 2012 at Korea University Anam Hospital. Patients were divided into two groups according to DRM measured in a formalin fixed specimen: ≤1cm (n=132) and >1cm (n=283). The DRM ≤1cm group was divided into two subgroups: ≤0.5cm (n=45) and >0.5, ≤1cm (n=87). Median follow-up periods were 47.2months. The 5-year local recurrence rate was 8.8% in the DRM ≤1cm group and 8.5% in the DRM >1cm group (p=0.630). The 5-year disease-free survival rate was 75.1 and 76.3% (p=0.895), and the 5-year overall survival rate was 82.6 and 85.9% (p=0.401), respectively. In subanalysis of the DRM ≤1cm group, there was also no significant difference in the local recurrence and survival. There was no significant difference in local recurrence and survival based on DRM length. We found that DRM length less than 1cm was not a prognostic factor for local recurrence or survival.