Open Access Highly Accessed Research article

Clinicopathologic features and prognostic implications of NOK/STYK1 protein expression in non-small cell lung cancer

Peng Chen, Wei-Miao Li, Qiang Lu, Jian Wang, Xiao-Long Yan*, Zhi-Pei Zhang* and Xiao-Fei Li*

Author Affiliations

Department of thoracic surgery, Tangdu hospital, Fourth Military Medical University, Xi’an, China

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BMC Cancer 2014, 14:402  doi:10.1186/1471-2407-14-402

Published: 4 June 2014

Abstract

Background

The expression of novel oncogenic kinase (NOK), a member of the protein tyrosine kinase (PTK) family, has been observed in several human malignancies including non-small cell lung cancer (NSCLC). However, the clinic relevance of NOK expression in NSCLC remains unclear.

Methods

In this study, NOK expression in tumor cells was assessed using immunohistochemical methods in 191 patients with resected NSCLC. The association of NOK expression with clinicopathological parameters, including the Ki-67 labeling index (LI), was also evaluated. Kaplan-Meier survival analysis and Cox proportional hazards models were used to estimate the effect of NOK expression on survival.

Results

Data showed that NOK was expressed in 75.4% and 14.1% of cancer lesions and corresponding adjacent non-cancerous tissue, respectively. Out of all the clinicopathological factors analyzed, NOK expression was significantly correlated with the grade of tumor differentiation (P = 0.035), pTNM stage (P = 0.020), lymphatic metastasis (P = 0.005) and high Ki-67 LI (P < 0.001). NOK positive NSCLC patients had a significantly shorter survival time (P = 0.004, Log-rank test) and the prognostic significance of NOK expression was apparent in squamous cell carcinoma patients (P = 0.022). Multivariate analysis indicated that NOK expression may be an independent prognostic factor in NSCLC (hazard ratio [HR], 1.731; P = 0.043).

Conclusions

Our results indicate that NOK expression is of clinical significance and can serve as a prognostic biomarker in NSCLC.

Keywords:
NOK; Oncogene; Lung cancer; NSCLC; Survival; Prognosis; Immunohistochemistry