Multiplex protein signature for the detection of bladder cancer in voided urine samples

Abstract

Purpose: Accurate urine assays for bladder cancer detection would benefit patients and health care systems. Through extensive genomic and proteomic profiling of urine components we previously identified a panel of 8 biomarkers that can facilitate the detection of bladder cancer in voided urine samples. In this study we confirmed this diagnostic molecular signature in a diverse multicenter cohort.

Materials and methods: We performed a case-control, phase II study in which we analyzed voided urine from 102 subjects with bladder cancer and 206 with varying urological disorders. The urinary concentration of 8 biomarkers (IL-8, MMP-9 and 10, PAI-1, VEGF, ANG, CA9 and APOE) was assessed by enzyme-linked immunosorbent assay. Diagnostic performance of the panel of tested biomarkers was evaluated using ROCs and descriptive statistical values, eg sensitivity and specificity.

Results: Seven of the 8 urine biomarkers were increased in subjects with bladder cancer relative to those without bladder cancer. The 7 biomarkers were assessed in a new model, which had an AUROC of 0.88 (95% CI 0.84-0.93), and 74% sensitivity and 90% specificity. In contrast, the sensitivity of voided urine cytology and the UroVysion® cytogenetic test in this cohort was 39% and 54%, respectively. Study limitations include analysis performed on banked urine samples and the lack of voided urine cytology and cytogenetic test data on controls.

Conclusions: The study provides further evidence that the reported panel of diagnostic biomarkers can reliably achieve the noninvasive detection of bladder cancer with higher sensitivity than currently available urine based assays.

Keywords: ANG; APOE; BCa; BIC; Bayesian information criterion; CA9; ELISA; IL-8; LUTS; MIBC; MMP; PAI-1; VEGF; VUC; angiogenin; apolipoprotein E; biological markers; bladder cancer; carbonic anhydrase 9; diagnosis; enzyme-linked immunosorbent assay; interleukin-8; lower urinary tract symptoms; matrix metalloproteinase; molecular biology; muscle invasive BCa; plasminogen activator inhibitor 1; urinary bladder neoplasms; urine; vascular endothelial growth factor; voided urine cytology.

Figure 1

Urine concentration of 8 biomarkers in BCa vs nonBCa groups normalized to urine creatinine. Cubic root transformation was applied to each biomarker value to decrease skewness. Horizontal lines indicate median. Significance was assessed by Wilcoxon rank sum test (p <0.05).

Figure 2

Diagnostic performance of urine biomarker combinations. ROC curves were plotted to compare diagnostic performance of 7 and 3 (IL-8, PAI-1 and MMP-9) biomarker signatures. Based on AUROC, Youden Index cutoffs (red circle) that maximized sum of sensitivity and specificity were determined for each combination.