Diagnostic Performance of Novel Urine-Based mRNA Tests (Xpert and Urinary Metabolomics Markers Assay) for Bladder Cancer Detection in Patients with Hematuria

Abstract

BACKGROUND: Hematuria is the most frequent presenting symptom in the vast majority of bladder cancer (BC) patients. The current recommended evaluation of hematuria includes cross sectional imaging and cystoscopy with possible high negative results, expensive costs and substantial patient burden. OBJECTIVES: To validate novel urine-based mRNA-dependant tests; Xpert test and urinary metabolomics assay (CRAT and SLC 25A20genes expression) for BC detection in patients with hematuria. METHODS: Patients presented with hematuria to our tertiary care hospital were evaluated by CT urogram and office white light cystoscopy with subsequent inpatient biopsy for positive findings. Voided precystoscopy urine samples were prospectively collected. Xpert test, assay of targeted urinary metabolomics and cytology, were performed. The tests characteristics presumably were calculated based on the ability to identify BC noninvasively. RESULTS: Between March 2018 and June 2019, 181 patients were included in the final analysis with mean (±SD) age 62 (±10) years with 168 (92.8%) males. Macroscopic hematuria was encountered in 153 (84.5%) patients with irritative bladder symptoms in 48 (26.5%) patients. BC was confirmed by cystoscopy/biopsy in 36 (19.9%) patients. The performance characteristics of Xpert alone (SN: 73%, SP: 83%, NPV: 92%, PPV: 52%) (AUC 0.84, 95% CI 0.75–0.93, p = 0.001), metabolomics assay alone (SN: 89%, SP: 93%, NPV: 97%, PPV: 78%) (AUC 0.91, 95% CI 0.85–0.98, p < 0.001) and combination of both test results (SN: 66%, SP: 98%, NPV: 92%, PPV: 97%) (AUC 0.83, 95% CI 0.74–0.93, p = 0.001) were notably superior to urine cytology (SN: 30%, SP: 84%, NPV: 83%, PPV: 33%) (AUC 0.58, 95% CI 0.47–0.69, p = 0.154) for BC prediction. Cystoscopy-negative patients (CNP) were followed-up for a median (range) 12 (2–19) months. Re-cystoscopy was done for 35 patients with persistent symptoms. BC was diagnosed in 6 patients. Xpert and urinary metabolomics results were observably positive in those 6 patients. CONCLUSION: Xpert test and assay of urinary metabolomics (CRAT and SLC 25A20 genes expression) have the potential for BC detection in hematuria patients. These non invasive urine based tests can help prioritization of the use of invasive diagnostic tests in systems with long waiting times.

Urine stabilization and normalization strategies favor unbiased analysis of urinary EV content

“…Therefore, we could not use a fixed RNA amount, but have decided to use an equal original urine volume for input normalization n amplification reactions. Such decision is in line with the common practice in diagnostic sampling 22 . MiRNAs are among the exosome cargo molecules that have elicited substantial interest and have been early approached for potential clinical interest.…”

The Role of Novel Bladder Cancer Diagnostic and Surveillance Biomarkers—What Should a Urologist Really Know?

“…The combination of 3 miRNAs and 2 lncRNAs, overly altered in BCa, was also evaluated, but did not display optimal diagnostic features (AUC = 0.910; sensitivity = 87.2% and specificity = 83.3%) [ 145 ], the same as coupling metabolomics assay and 5 target mRNAs (Xpert panel) resulting in NPV of 98.2%, not much better than when used singularly [ 146 ].…”

RNA-based urinary assays for non-muscle invasive bladder cancer

“…An overview of the five studies is shown in Table 2. The Xpert Bladder Cancer test, which assessed five mRNA targets ( ABL1, CRH, IGF2, UPK1B, and ANXA10 ) was evaluated in two studies [18 ▪ ,19]. This test combines expression levels of the markers in a linear discriminate analysis (LDA) to classify samples as positive or negative in a linear model [23].…”

“…Five articles reported on the diagnostic performance of an RNA-based urinary assay as a diagnostic tool to detect urothelial cancer of the bladder in patients presenting with hematuria [18 ▪ ,19–22]. In all studies, the presence of urothelial cancer was confirmed by histological examination.…”