Eg5 high expression predicts dismal prognosis in epithelial ovarian cancer

The expression of kinesin spindle protein (Eg5) and its significance of clinical prognosis of patients with epithelial ovarian cancer (EOC) were evaluated in this study. Forty-five fresh frozen tissue samples for quantitative real-time polymerase chain reaction (qPCR) and 196 samples for immunohistochemistry (IHC) analysis with tissue microarray (TMA) were applied to characterize Eg5 mRNA and protein expressions in EOC. The correlation between clinical parameters and Eg5 protein expression was investigated using statistical analysis. The expression of Eg5 protein was significantly higher in EOC tissues compared with that in corresponding non-cancerous tissues (P < 0.05). The high Eg5 expression was significantly correlated with older age (P = 0.003), higher stage (P = 0.001), presence of metastasis (P = 0.041) and higher CA125 serum level (P = 0.013). For univariate analysis, associated prognostic markers in patients with ovarian cancer were analyzed for correlations with poor overall survival, including Eg5 (P = 0.011), age (P = 0.001), FIGO stage (P = 0.011), CA125 serum level (P = 0.001), lymph nodes (P = 0.012), and metastasis (P = 0.001). For multivariate analysis, Eg5 expression, FIGO stage and age were independent factors found contributing to a largely unfavorable prognosis in patients with ovarian cancer. In conclusion, the high expression of Eg5 is correlated with an unfavorable prognosis in EOC.