Prognostic Significance of Circumferential Resection Margin Following Total Mesorectal Excision and Adjuvant Chemoradiotherapy in Patients with Rectal Cancer

Abstract

This study was designed to evaluate the prognostic value of circumferential resection margin (CRM) in rectal cancer patients who underwent curative resection with adjuvant chemoradiotherapy (CRT). We studied 504 patients who underwent total mesorectal excision with adjuvant CRT for rectal cancer between 1997 and 2001. The patients were divided into two groups: a negative CRM group (CRM > 1 mm) and a positive CRM group (CRM ≤ 1 mm). The survival rates, local recurrence rates, and systemic recurrence rates were compared between groups. The negative CRM group had 460 patients and the positive CRM group had 44 patients. The 5-year local and systemic recurrence rates were 11.3 and 25.3%, respectively, in the negative CRM group and 35.2 and 60.8% in the positive CRM group, respectively. The cancer-specific 5-year survival rates for the two groups were 72.5 and 26.9% (P < .001), respectively. CRM was found to be an independent prognostic factor by multivariate analyses which were adjusted for known outcome predictors (P < .001). Oncological outcome for patients in the positive CRM group is less favorable than for those in the negative CRM group. Adjuvant CRT is not a definite treatment modality that can be used to compensate for a positive CRM following TME and adjuvant CRT in patients with TNM stage II or III rectal cancer.