What is a safe distal resection margin in rectal cancer patients treated by low anterior resection without preoperative radiotherapy?

Aim The aim of this study was to examine what constitutes an acceptable distal resection margin (DRM) when performing sphincter-saving surgery for rectal cancer without preoperative radiotherapy. Method This national study consisted of 3571 patients for whom information on DRM was available and who were radically treated by anterior resection between 1993 and 2004. Of these, 3342 (93.5%) patients had not received preoperative radiotherapy. The DRM was measured on fixed specimens. Results The 5-year local recurrence rate was 14.5% for patients with a DRM of 0-10 mm compared to 9.6% for patients with a DRM of 11-20 mm, 8.9% for a DRM of 21-30 mm, 7.0% for a DRM of 31-40 mm, 7.7% for a DRM of 41-50 mm and 8.7% for a DRM of > 50 mm. After adjustment for other independent prognostic factors, a DRM of 0-10 mm was found to have significant impact on local recurrence. The DRM had no impact on distant metastases or overall survival. Conclusion For rectal cancer patients treated without radiotherapy, a DRM of > 10 mm is recommended.