LAUSR

BACKGROUND In the past few years, positive circumferential resection margin has been found to be an indicator of advanced disease with high risk of distant recurrence rather than of local recurrence. OBJECTIVE The objective was to analyze the prognostic impact of circumferential resection margin on local recurrence, distant recurrence, and survival rates in patients with rectal cancer. DESIGN This was a multicenter, propensity score-matched analysis 2:1 comparing positive and negative circumferential resection margin. SETTINGS The study was conducted at 5 high-volume centers in Spain. PATIENTS Patients who underwent total mesorectal excision with a curative intent for middle-low rectal cancer between 2006 and 2014 were included. Clinical and histological characteristics were used for matching. MAIN OUTCOME MEASURES The main outcomes were local recurrence, distant recurrence, overall survival, and disease-free survival. RESULTS The unmatched initial cohort consisted of 1599 patients; 4.9% had a positive circumferential resection margin. After matching, 234 patients were included (156 with negative circumferential margin and 78 with positive circumferential margin). The median follow-up period was 52.5 months (22.0-69.5). Local recurrence was significantly higher in patients with positive circumferential margin (33.3% vs 11.5%; HR 3.2; 95% CI: 1.83-5.43; p < 0.001). Distant recurrence was similar in both groups (46.2% vs 42.3%; HR 1.09; 95% CI: 0.78-1.90; p = 0.651). There were no statistically significant differences in 5-year overall survival (48.6% vs 43.6%; HR 1.09; 95% CI: 0.92-1.78; p = 0.14). Disease-free survival was lower in patients with positive circumferential margin (36.1% vs 52.3%; HR 1.5; 95% CI: 1.05-2.06; p = 0.026). LIMITATIONS This study was limited by its retrospective design. The different neoadjuvant treatment options were not been included in the propensity score. CONCLUSIONS Positive circumferential resection margin is associated with higher local recurrence rate and worse disease-free survival in comparison with negative circumferential resection margin. However, positive circumferential resection margin was not a prognostic indicator of distant recurrence and overall survival. See Video Abstract at http://links.lww.com/DCR/B950.