Overexpression of Eg5 predicts unfavorable prognosis in non-muscle invasive bladder urothelial carcinoma.

Objective: To investigate the relationship between Eg5 expression and prognosis of patients with non-muscle invasive bladder urothelial carcinoma.

Methods: Eg5 expression was examined by immunohistochemistry in non-muscle invasive urothelial carcinoma specimens (grade: G1, 32 cases; G2, 92 cases; and G3, 39 cases. Stage: pTa, 49 cases and pT1, 114 cases). The correlation between clinicopathological characteristics and Eg5 expression was evaluated. The prognostic significance of Eg5 immunoreactivity was analyzed through survival analysis in 163 non-muscle invasive cases that were treated with transurethral resection and adjuvant intravesical instillations.

Results: The expression of Eg5 was significantly associated with tumor grade (P = 0.006), with a trend towards significant association with stage (P = 0.057). The 163 patients with non-muscle invasive tumors were regularly followed with the mean of 32.52 (from 6 to 72) months. Univariate analysis showed Eg5 overexpression exhibited a significant unfavorable influence on intravesical recurrence (P = 0.012) while having only a marginal correlation with disease progression (P = 0.070). Subsequent Cox hazard multivariate analysis showed that both grade (P = 0.045) and Eg5 expression (P = 0.029) were independent predictors for early intravesical recurrence.

Conclusions: Overexpression of Eg5 correlates with poor differentiation of bladder cancer, and it represents an independent prognostic factor in predicting early intravesical recurrence in non-muscle invasive bladder carcinoma patients.