Coexistence of Perineural Invasion and Lymph Node Metastases Is a Poor Prognostic Factor in Patients with Locally Advanced Rectal Cancer after Preoperative Chemoradiotherapy Followed by Radical Resection and Adjuvant Chemotherapy

OBJECTIVE To determine the role of lymph node metastases (ypN) and perineural invasion (PNI) in patients with locally advanced rectal cancer (LARC). SUBJECTS AND METHODS Eighty-eight LARC patients receiving preoperative chemoradiotherapy from April 2006 to November 2011 were enrolled in this study. Univariate and multivariate analyses were conducted to determine the association between clinicopathologic features and clinical outcome. RESULTS The presence of ypN (p = 0.011) and PNI (p = 0.032) was a significant adverse prognostic factor for disease-free survival (DFS). High histologic grade (p = 0.015), PNI+ (p = 0.043) and ypN+ (p = 0.041) were adverse prognostic factors for overall survival (OS). Positive PNI was significantly associated with a higher risk of distant failure (odds ratio = 6.09; 95% CI: 1.57-27.05; p = 0.008). Moreover, patients with a coexistence of ypN+ and PNI+ had the significantly worst DFS (p < 0.001) and OS rates (p < 0.001) compared with other phenotypes. CONCLUSIONS The presence of either PNI or ypN was a significant prognostic factor for predicting poor survival rates in LARC patients, especially those with a coexistence of both factors. Accordingly, we recommend an intensive follow-up and therapeutic programs for LARC patients with simultaneous PNI+ and ypN+.