Prognostic significance of circumferential margin involvement in rectal adenocarcinoma treated with preoperative chemoradiotherapy and low anterior resection.

Introduction Histologic examination of circumferential margins is an important predictor of local and distant relapse in non-radiated rectal cancer. However, for patients who received preoperative chemoradiotherapy this role has not yet been addressed. Methods From January 1995 to December 1997, 61 patients with rectal adenocarcinoma located between 0 and 10 cm from anal verge with invasion into perirectal fat assessed by rectal ultrasound were included. All patients received 45 Gy + bolus infusion of 5-FU (450 mg/m2/days 1–5, 28–33 of RT); 4–6 weeks later, surgery was performed. Circumferential margin was assessed (<2 mm was considered as positive). Five-year survival was calculated by Kaplan–Meier method and comparison of groups with log-rank test. Multivariate Cox regression analysis was performed to find risk factors affecting local control and survival. Results There were 35 males and 26 females, mean age 60.3 years. Twelve patients (19.7%) had circumferential margin involvement. Median follow-up was 44 months. Overall local recurrence was observed in 6 of 61 patients (9.8%); in patients without circumferential margin involvement this was 8%, whereas it was 16% in those with circumferential margin involvement (P = 0.33). Distant recurrence was observed in 22% of patients without circumferential margin involvement; conversely, it was 58.3% in those with involvement (P = 0.02). Five-year survival of patients without circumferential resection involvement margin was 81%, while it was 42% in patients with circumferential involvement (P = 0.006). Conclusions In patients with rectal cancer treated by preoperative chemoradiation plus total mesorectal excision (TME) and sphincter saving surgery, circumferential margin involvement is associated with high incidence of distant recurrence and cancer-related death. J. Surg. Oncol. 2005;90:20–25. © 2005 Wiley-Liss, Inc.