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

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 ≤1 cm in sphincter-saving resection for rectal cancer. The outcomes of a DRM ≤0.5 cm 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: ≤1 cm (n = 132) and >1 cm (n = 283). The DRM ≤1 cm group was divided into two subgroups: ≤0.5 cm (n = 45) and >0.5, ≤1 cm (n = 87).

Median follow-up periods were 47.2 months. The 5-year local recurrence rate was 8.8% in the DRM ≤1 cm group and 8.5% in the DRM >1 cm 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 ≤1 cm 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 1 cm was not a prognostic factor for local recurrence or survival.