Impact of perineural invasion as a histopathological prognostic factor in ypStage II/III oesophageal squamous cell carcinoma†.

Abstract

The 8th edition American Joint Committee on Cancer Tumour-Nodes-Metastasis (TNM) staging system distinguishes between the clinical (c), pathological (p) and post-neoadjuvant pathological (yp) stage groups. However, the ability to discriminate between ypStage II and ypStage III is poor. We aim to identify prognostic factors in patients with ypStage II/III oesophageal squamous cell carcinoma. The data of 150 patients with ypStage II/III oesophageal squamous cell carcinoma from 2 medical centres were retrospectively reviewed. The neoadjuvant treatments included chemotherapy with cisplatin and 5-fluorouracil, administered concurrently with external beam radiation. The determination of perineural invasion (PNI) was based on pathological reports. Survival curves were compared using the log-rank test, and multivariable survival analysis was performed with a Cox regression model. The 3-year/5-year overall survival rate/median survival in ypStages II, IIIa and IIIb were 35.3%/26.9%/21.9 [95% confidence interval (CI) 14.9-28.8] months, 33.8%/22.5%/22.4 (95% CI 20.1-24.7) months and 21.7%/14.0%/14.4 (95% CI 11.1-17.7) months, respectively (P = 0.07). The 3-year/5-year overall survival rate/median survival was 36.7%/26.4%/22.8 (95% CI 19.2-26.5) months in the absence of PNI and 6.9%/3.4%/9.1 (95% CI 8.9-9.4) months in the presence of PNI (P < 0.001). In the multivariable survival analysis, tumour location in the upper third of the thoracic oesophagus [hazard ratio (HR) 1.692, 95% CI 1.087-2.635; P = 0.020] and positive PNI (HR 3.316, 95% CI 2.005-4.905; P < 0.001) remained as independent prognostic factors. The existence of PNI after neoadjuvant treatment is closely associated with poor prognosis and could be incorporated into the TNM staging system for better discrimination between patients with ypStage II/III oesophageal squamous cell carcinoma.