Expression of Stathmin in Localized Upper Urinary Tract Urothelial Carcinoma: Correlations With Prognosis

Abstract

To investigate the expression of stathmin in upper urinary tract (UUT) urothelial carcinoma (UC) in human tissues and to determine whether the level of stathmin expression was correlated with prognosis because overexpression of stathmin has been observed in various malignancies. We first analyzed stathmin mRNA level in 5 UUT-UC paired fresh specimens (tumor and nontumoral urothelium) by RT-PCR. Besides, a total of 58 patients with localized UUT-UC (pT1-3N0M0) treated by nephroureterectomy were enrolled. The stathmin expression in UUT-UC specimens was analyzed by immunohistochemical (IHC) staining. Stathmin IHC score was defined as the proportion of positive staining tumor cells from each patient's specimen. The stathmin IHC score > or = 0.5 was defined as strong (+) immunoreactivity and < 0.5 as weak (-) immunoreactivity. Significant differences in stathmin mRNA between UUT-UC and paired normal urothelium were noted in 5 of the patients. Of the 58 UUT-UC specimens, stathmin immunoreactivity (strong [+] vs weak [-]) was significantly associated with pT stage (P = .006) as well as with recurrence-free and cancer-specific survival. In multivariate analysis, stathmin IHC score was a significant predictor for both recurrence-free survival (hazard rates: 22.4; P = .001) and cancer-specific survival (hazard rates: 39.8; P = .0012). The stathmin immunostaining is a novel prognosticator for patients with localized UUT-UC stathmin may be a help identify such patients with poor outcomes to benefit from receiving close follow-up and early adjuvant therapy.