Perineural invasion correlates with postoperative distant metastasis and poor overall survival in patients with _PT _1–3N ₀M ₀ esophageal squamous cell carcinoma

Abstract

The aim of this study was to determine the prognostic value of perineural invasion (PNI) in patients with _PT _1–3N ₀M ₀ esophageal squamous cell carcinoma (ESCC) who underwent curative resection. A total of 148 patients with _PT _1–3N ₀M ₀ ESCC, who underwent surgery in Zhejiang Cancer Hospital (Hangzhou, People’s Republic of China), between 2006 and 2009, were evaluated in this retrospective study. The effects of PNI on distant metastasis-free survival (DMFS) and overall survival (OS) were assessed using Kaplan–Meier analysis. Independent prognostic factors were identified by multivariate Cox analysis. Positive PNI was identified in 25.0% of all the cases. The depth of invasion (PT stage) was closely associated with the PNI positivity ( P<0.001). The 5-year DMFS rate and OS rate of the PNI-positive patients were significantly worse than those of the PNI-negative patients (DMFS: 37.2% vs 62.3%, P=0.009; OS: 31.3% vs 74.3%, P,0.001). Multivariate analysis indicated that the positivity of PNI was an independent prognostic factor for both DMFS (hazard ratio [HR] =2.35, P=0.039) and OS (HR =3.56, P=0.002). Our results suggest that PNI was a predictor of distant metastasis and independently associated with prognosis of patients with _PT _1–3N ₀M ₀ ESCC.