IL-8 as a urinary biomarker for the detection of bladder cancer

Voided urines from 127 subjects, cancer subjects (n？=？64), non-cancer subjects (n？=？63) were analyzed. The protein concentrations of IL-8, MMP-9, and Syndecan were assessed by enzyme-linked immunosorbent assay (ELISA). Data were also compared to a commercial ELISA-based BCa detection assay (BTA-Trak？) and urinary cytology. We used the area under the curve of a receiver operating characteristic (AUROC) to compare the performance of each biomarker.Urinary protein concentrations of IL-8, MMP-9 and BTA were significantly elevated in BCa subjects. Of the experimental markers compared to BTA-Trak？, IL-8 was the most prominent marker (AUC; 0.79; 95% confidence interval [CI], 0.72-0.86). Multivariate regression analysis revealed that only IL-8 (OR; 1.51; 95% CI, 1.16-1.97, p？=？0.002) was an independent factor for the detection of BCa.These results suggest that the measurement of IL-8 in voided urinary samples may have utility for urine-based detection of BCa. These findings need to be confirmed in a larger, prospective cohort.Voided urinary cytology (VUC) remains the most established adjunct to cystoscopy in the detection of BCa. While VUC has a specificity of >93%, its sensitivity is only 25-40%, especially for low-grade and low-stage tumors [1]. Commercial tests measuring nuclear matrix protein (NMP-22) and bladder tumor antigen (BTA) have emerged as diagnostic urinary protein assays for BCa. The analysis of naturally shed urothelial cells isolated from the urine, as used in VUC, can be enhanced by combining VUC with molecular assays to detect protein biomarkers or aberrant chromosomes. ImmunoCyt？ uses fluorescent monoclonal antibodies to detect mucin antigen and carcinoembryonic antigen on urothelial cells [2]. Urovysion？, a fluorescence in situ hybridization assay designed to detect aneuploidy for chromosomes 3, 7, 17, and loss of the 9p21, can be applied to VUC slides [3]. Unlike VUC, these tests have a lower specificity, thus there is currently no urine test for BCa t