Upregulation of cyclin D1 can act as an independent prognostic marker for longer survival time in human nasopharyngeal carcinoma.

Background: Cyclin D1 is an essential part of oncogenic transformation. We previously proved that cyclin D1 was upregulated in nasopharyngeal carcinoma (NPC) and promoted the NPC cell proliferation. But the association between cyclin D1 and the clinical outcome of NPC has not yet been determined. The study explores the possible relevance between the cyclin D1 expression and clinical parameters and its predictive value of prognosis in NPC patients.

Methods: We analyzed the clinical data from 379 NPC patients and 112 non-NPC patients in our previous study, which made further statistics. Receiver operating curve (ROC) was applied to select the optimal cutoff points. By analyzing the clinical data from 101 NPC patients using Chi-squared test, we estimated the relationship between the cyclin D1 expression level and clinicopathological parameters. We also used Kaplan-Meier method and log-rank test assess and compared the disease-free survival (DFS) rate and overall survival (OS) rate. The Cox proportional hazards model was adopted to perform the univariate and multivariate analyses.

Result: Receiver operating curve analysis reported that cyclin D1 was used to differentiate between NPC patients and non-NPC patients (P < .001, sensitivity: 53.6%, specificity: 85.7%, AUC = 0.752). Cyclin D1 was positively correlated with lymph node metastasis (P = .015). A survival analysis of the 101 NPC patients indicated that the positive expression of cyclin D1 was predictive of a good prognosis (DFS: P = .010, OS: P = .019). Multivariate analysis showed that cyclin D1 could be used independently to predict NPC patients' prognosis (DFS: P = .038).

Conclusion: The overexpression of cyclin D1 is a good prognostic marker for NPC.