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/m(2)/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. (c) 2005 Wiley-Liss, Inc.