Narrow distal resection margin may be sufficient for rectal cancer after chemoradiation.

Background/aims: What constitutes an adequate length for the distal resection margin in patients with mid-to-distal rectal cancer after pre-operative chemoradiation therapy (PCRT) continues to be debated. The purpose of the present study was to determine the effect of the distal resection margin on oncological outcome and establish a guideline for the distal resection margin in patients with rectal cancer after PCRT.

Methodology: Data from 204 patients undergoing low anterior resection after completion of chemoradiation therapy were examined. Associations between clinicopathological parameters, including the distal resection margin and oncological outcome, were analyzed retrospectively.

Results: The distal resection margin was not significantly associated with local recurrence-free survival, disease-free survival, or overall survival; subgroup analysis of the T3,4 group showed the same results. Further analysis using various lengths (0.5, 1.5, 1 and 2cm) of the resection margin did not show statistical significance for oncological outcomes. Pre-PCRT clinical stage, post-PCRT pathological T stage, and histological grade were significantly associated with disease-free survival.

Conclusions: For patients with locally advanced rectal cancer undergoing resection and pre-operative chemoradiotherapy, a narrow distal resection margin did not compromise oncological outcomes.