Abdominoperineal excision following preoperative radiotherapy for rectal cancer: unfavorable prognosis even with negative circumferential resection margin.

Abstract

To evaluate whether an abdominoperineal excision (APE) is associated with increased local recurrence (LR) and shortened disease-free survival (DFS) in mid-low rectal cancer with a negative circumferential resection margin (CRM). 283 consecutive cases of mid-low rectal cancer underwent preoperative 30 Gy/10 F radiotherapy and surgery in Peking University Cancer Hospital between August 2003 and August 2009. Patients with positive CRM and intraoperative distant metastasis were precluded according to exclusion criteria. Survival analyses were performed in patients with APE or non-APE procedures. 256 of the 283 (90.5%) cases were enrolled in the analysis, including 78 (30.5%) and 178 (69.5%) cases who received APE and non-APE procedures. Fewer female patients (P = 0.016), lower level of tumor (P = 0.000) and higher body mass index (P = 0.006) were found in the APE group. On univariate analysis, the APE group had a higher LR rate (5.1% vs 1.1%, P = 0.036) and decreased DFS (73.1% vs 83.4%, P = 0.021). On multivariate analysis, APE procedure was also an independent risk factor for LR (HR = 5.960, 1.085-32.728, P = 0.040) and decreased DFS (HR = 2.304, 1.298-4.092, P = 0.004). In stratified analysis for lower rectal cancer, APE procedure was still an independent risk factor for higher LR rate (5.6% vs 0%, P = 0.024) and shortened DFS (91.5% vs 73.6%, P = 0.002). Following preoperative 30 Gy/10 F radiotherapy, APE procedure was still a predictor for LR and decreased DFS even with negative CRM. More intensive preoperative treatment should be planned for the candidates who are scheduled to receive APE with optimal imaging assessment.