Stress Proteins and Cytokines are Urinary Biomarkers for Diagnosis and Staging of Bladder Cancer

Background: Cancer often involves inflammatory processes. We hypothesized that immune mediators in urine may serve as biomarkers for bladder cancer (BCa). Objective: To investigate whether BCa might be marked by urinary levels of heat shock proteins (HSPs; HSP60, HSP70, or HSP90) or cytokines (interferon [IFN]-gamma, tumor necrosis factor [TNF]-alpha, tumor growth factor [TGF]-beta, interleukin [IL]-1 beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, or IL-13). Design, setting, and participants: This was a case-control study with a discovery and validation phase. We examined urine from 106 consecutive patients: healthy controls (n = 18); hematuria with no evidence of BCa (n = 20); non-muscle-invasive BCa (n = 50); and muscle-invasive BCa (n = 18). The concentrations of HSPs and cytokines were assessed by enzyme-linked immunosorbent assay. In the validation phase, independent urine samples from 40 patients were analyzed (controls [n = 19] and BCa [n = 21]). Measurements: We used the area under the curve (AUC) of a receiver operating characteristic analysis to determine the ability of HSPs and cytokines to mark BCa and applied a multivariate logistic regression to create a formula able to diagnose BCa. The formula was applied to the validation set without recalculation, and positive and negative predictive values were calculated. Results and limitations: Urinary concentrations of IL-8, IL-10, and IL-13 were significantly elevated in BCa; IL-13 was the most prominent marker (AUC: 0.93; 95% confidence interval [CI], 0.85-0.99). The multivariate regression analysis highlighted HSP60 (odds ratio [OR]: 1.206; 95% CI, 1.041-1.397, p = 0.003) and IL-13 (OR: 1.020; 95% CI: 1.007-1.033, p = 0.012). The validation assay was performed using HSP60 and IL-13. The overall positive predictive value was 74% (95% CI, 64-84%); and the negative predictive value was 76% (95% CI, 66-86%). Since we examined a small number of patients, the results need to be confirmed in a larger cohort. Conclusions: These results suggest that it might be possible to develop a urinary biomarker for BCa and raise the possibility that expression of anti-inflammatory cytokines and HSPs might allow BCa to evade immune surveillance. (C) 2010 European Association of Urology. Published by Elsevier B.V. All rights reserved.