Abstract
Aberrant expression of the IRX2 gene contributes to the oncogenesis and progression of various cancers. In this study, we analyzed the clinical significance and the prognostic value of mRNA expression level of the IRX2 gene in nasopharyngeal carcinoma (NPC) patients, with the goal to find a novel prognostic biomarker for NPC. Tissue samples were collected prior to treatment from 71 NPC patients for the detection of mRNA expression level of a total of 31503 genes, with high throughput screening of the mRNA expression profile. The Kaplan-Meier curves and log-rank test were used for univariate analyses to determine if the mRNA expression level of IRX2 and other 31502 genes, as well as clinical characteristics were of prognostic value for overall survival (OS), distant metastasis-free survival (DMFS) and disease-free survival (DFS). Regularized Cox regression was performed to test the contribution of prognostic factors to OS, DMFS, and DFS of NPC patients. The Cox proportional hazard model was used to test the independence of prognostic effect of IRX2 and other clinical features. The receiver operator characteristic curve was drawn and the area under the curve (AUC) was calculated to evaluate the predictive power of IRX2 gene. Univariate analyses showed a higher mRNA expression level of the IRX2 gene correlated with shorter OS (P = 0.001), DMFS (P = 0.003), and DFS (P = 0.007). Regularized Cox regression and Cox proportional hazard model analyses further showed that ahigher mRNA expression level of the IRX2 gene in the primary NPC was an independent prognostic factor for OS (Coxnet beta = 0.03, Cox proportion hazard model P = 0.038), DMFS (Coxnet beta = 0.018, Cox proportion hazard model P = 0.01) and DFS (Coxnet beta = 0.008, Cox proportion hazard model P = 0.029). The AUC showed that the mRNA expression level of the IRX2 gene is a significant predictor for predicting the OS (AUC value = 0.7105) and DMFS (AUC value = 0.7027) of NPC patients. Our results demonstrated that the IRX2 gene may be a novel independent unfavorable prognostic factor for NPC patients.