High Levels of Thymidine Phosphorylase as an Independent Prognostic Factor in Renal Cell Carcinoma

Abstract

Background:We investigated whether thymidine phosphorylase (TP) protein level in renal cell carcinoma (RCC) correlates with clinicopathological characteristics and clinical outcomes. Methods:TPprotein level wasmeasured in 116RCCspecimens and in 90 non-neoplastic kidney tissues using a sandwich-type enzyme-linked immunosolvent assay. Results: The median TP protein level in RCC tissues was 9.76-fold (range, 3.2–933.9) higher than those in non-neoplastic kidney tissues (P < 0.0001). TP protein level was correlated with Tclassification, histological gradeandmodeof infiltration. TPasaprognostic variablewas studied using a logistic regression model. TP at higher levels (128 U/mg protein or greater) would play a role as an independent prognostic factor (odds ratio, 13.73; 95 % confidence interval, 2.09–90.41; P = 0.0064). Conclusion: TP at high levels can be regarded as an unfavorable independent prognostic factor. These results may pave a way for a novel approach to effective treatment of RCC. Key words: renal cell carcinoma – thymidine phosphorylase – prognostic facto