Prognostic significance of nemo-like kinase in nasopharyngeal carcinoma

Abstract

Nasopharyngeal carcinoma (NPC) is a highly metastatic malignancy, which is highly prevalent in Southeast Asia and North Africa. Recent studies implicated the critical role of nemo-like kinase (NLK) in tumor biology. However, the functional role of NLK in NPC has yet to be elucidated. In the present study, the significance of NLK positivity in NPC was examined. NLK expression was evaluated by immunohistochemistry in a relatively large sample of patients with NPC (n=352) from December 1, 2002 to December 1, 2009. The correlation between the NLK expression status and clinicopathological features and prognosis was investigated. Univariate and multivariate Cox regression models were developed to evaluate the association between the NLK status and the relative risks for relapse and mortality. In total, 54% (190/352) of NPC samples were identified as positive for NLK. By contrast, all 176 specimens of adjacent normal tissue were negative for NLK. NLK positivity was associated with tumor extent, regional lymph node status and distant metastases. A Kaplan-Meier survival analysis demonstrated that patients with NLK-positive NPC exhibited significantly shorter disease-free survival (DFS) and overall survival (OS). Furthermore, Cox regression analysis revealed that NLK positivity was an unfavorable prognostic indicator of DFS and OS in NPC, independent of other features. Additionally, NLK-positive patients with NPC without distant metastases were more likely to relapse compared with NLK-negative patients with NPC without distant metastases. The present study indicates that NLK is a good prognostic marker for NPC.