Frequent overexpression of PDK1 in primary nasopharyngeal carcinoma is associated with poor prognosis

ObjectivePyruvate dehydrogenase kinase 1 (PDK1) is reported to be up-regulated and play multiple functions in several cancers. Herein, we investigated its roles in primary nasopharyngeal carcinoma.MethodsExpression of PDK1 protein was examined by immunohistochemical staining in 102 samples of primary nasopharyngeal carcinoma (pNPC) and 31 samples of chronic nasopharyngitis. The relationships of PDK1 expression levels with clinical features and prognosis in NPC patients were analyzed.ResultsPDK1 protein expression was significantly greater in pNPC tissues than in the chronic nasopharyngitis tissues (P < 0.01). In addition, overexpression of PDK1 was associated with advanced clinical stage (P < 0.01), advanced N classification (P = 0.024), and distant metastasis (P = 0.048). Kaplan-Meier survival analysis demonstrated that patients with higher PDK1 expression had significantly shorter overall survival (P = 0.006), disease-free survival (P = 0.015), loco-regional relapse-free survival (P = 0.008), and distant metastasis-free survival (P = 0.017). Furthermore, multi-variate analysis showed that PDK1 expression was an independent prognostic factor in pNPC patients.ConclusionPDK1 is frequently upregulated in pNPC and may serve as a prognostic marker.