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

Diagnostic Performance of GeneXpert BC as a Triage Test for Patients Presenting with Macroscopic Hematuria Suspicious for Urinary Bladder Cancer: A Multicenter Prospective Case-Control Study

Background and objective

Our objective was to assess whether GeneXpert BC can be used as a triage test to exclude urinary bladder cancer (UBC) for patients with macroscopic hematuria.

Methods

We conducted a prospective study that include consecutive patients being evaluated for macroscopic hematuria between September 2020 and December 2022. Before cystoscopy, study participants provided a voided urine sample for GeneXpert BC analysis according to a case-control design with an emphasis on UBC detection. Descriptive statistics are reported for patient and tumor characteristics. To assess the diagnostic accuracy of the GeneXpert BC test, the sensitivity, specificity, and negative predictive value (NPV) were calculated, using the histopathologically proven UBC as the ground truth.

Key findings and limitations

In total, 1505 subjects presenting with macroscopic hematuria were enrolled in the study. After randomization and exclusions, GeneXpert BC testing was carried out for 312 participants. Of these, 151 patients from the case arm had UBC, 122 patients from the control arm (random 10%) were negative for UBC, and 39 patients from the case arm did not have malignancy. Using a predefined linear discriminant analysis (LDA) threshold of ≥0.22, the test had sensitivity of 0.94 (95% confidence interval [CI] 0.90-0.97), specificity of 0.52 (95% CI 0.42-0.59), and NPV of 0.99 (95% CI 0.98-0.99). All false-negative tumors were of low grade (Ta grade 1-2). Cystoscopy and computed tomography urography could have been omitted in 44% of the patients with macroscopic hematuria. At a secondary LDA threshold of ≥0.45, the test had sensitivity of 0.79 (95% CI 0.73-0.86), specificity of 0.83 (95% CI 0.76-0.89), and NPV of 0.97 (95% CI 0.96-0.98).

Conclusions and clinical implications

GeneXpert BC is a reliable triage test for deciding on whether further investigations are necessary in patients with macroscopic hematuria.

Patient summary

We assessed a test called GeneXpert BC for the detection of bladder cancer in patients with blood in their urine. GeneXpert BC performed well in ruling out bladder cancer for patients who did not have cancer according to further tests. Use of GeneXpert BC could help in avoiding scans and invasive tests for patients with a negative result.

Novel urine-based DNA methylation biomarkers for urothelial bladder carcinoma detection in patients with hematuria

Background

Urothelial bladder carcinoma (UBC) is usually detected during work-up for hematuria. Cystoscopy and/or contrast-enhanced imaging are the gold standard tools for UBC diagnosis, despite limited by being invasive, expensive and low yield in small flat tumors.

Objectives

To assess the diagnostic performance of urine-based DNA methylation of six genes (GATA4, P16, P14, APC, CDH1 and CD99) for UBC detection in patients with hematuria.

Patients and methods

Voided urine was collected from consecutive patients presented with hematuria for urine cytology and DNA methylation assay of the assigned genes using methylation-specific Polymerase Chain Reaction (PCR). Further assessment by office cystoscopy and imaging with subsequent inpatient cystoscopic biopsy for positive findings was done. The diagnostic characteristics of DNA methylation and urine cytology were assessed based on its capability to predict UBC.

Results

We included 246 patients in the study with identified macroscopic hematuria in 204 (82.9%) patients. Positive cytology was found in 78 (31.7%) patients. DNA methylation of GATA4, P16, P14, APC, CDH1 and CD99 genes was identified in 127 (51.6%), 52 (21.1%), 117 (47.6%), 106 (43.1%), 90 (36.6%) and 71 (28.9%) patients, respectively. The sensitivity of the assigned genes for UBC detection ranges from 35% (95%CI: 31-39) to 83% (95%CI: 79-87). Optimal specificity (SP) (100%) was noted for P16, APC and CDH1 genes. While for the other genes (GATA4, P14 and CD99), the SP was 95% (95%CI: 92-98), 96% (95%CI: 92-99) and 97% (95%CI: 93-99), respectively. On multivariate logistic regression analysis, all genes exclusively demonstrated independent prediction of UBC. On receiver operator characteristic (ROC) analysis, all tested genes methylation showed superior area under the curve (AUC) when compared to urine cytology.

Conclusions

We have developed a novel urine-based DNA methylation assay for detection of UBC in patients with hematuria with superior diagnostic performance and independent predictive capacity over urine cytology.

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

PURPOSE OF REVIEW

To provide an overview of the recent literature on RNA-based molecular urine assays for the diagnosis and surveillance of non-muscle invasive bladder cancer (NMIBC).

RECENT FINDINGS

Articles were eligible for inclusion if performance metrics sensitivity, specificity, and negative-predictive value (NPV) were reported or could be calculated. Only prospective studies published between 2020-2022 were included. Five out of fourteen studies addressed the primary diagnostic setting; the proportion of gross hematuria patients in all study populations was >50%. Only one study reported performance metrics within a microscopic hematuria subgroup. This study evaluated Xpert Bladder and reported a sensitivity: 73%, specificity: 84%, NPV: 99%, and PPV: 12%. Ten studies assessed test performance during surveillance for NMIBC. For the detection of high-grade (HG) and high-risk (HR) NMIBC, sensitivity, specificity, NPV, and PPV varied between 78-100%, 64-89%, 97.0-99.7%, and 9.2-39%.

SUMMARY

Multiple RNA-based urine assays have been investigated for the detection of urothelial cancer in the primary or surveillance setting. However, studies included within this review have important limitations, hampering the interpretation of study results. As such, performance metrics should be interpreted with caution and further research is required to evaluate the clinical impact of RNA-based urine assays in daily practice.

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

The aim of this review is to analyze and describe the current landscape of bladder cancer diagnostic and surveillance biomarkers. We researched the literature from 2016 to November 2021 to find the most promising new molecules and divided them into seven different subgroups based on their function and location in the cell. Although cystoscopy and cytology are still the gold standard for diagnosis and surveillance when it comes to bladder cancer (BCa), their cost is quite a burden for national health systems worldwide. Currently, the research is focused on finding a biomarker that has high negative predictive value (NPV) and can exclude with a certainty the presence of the tumor, considering missing it could be disastrous for the patient. Every subgroup has its own advantages and disadvantages; for example, protein biomarkers cost less than genomic ones, but on the other hand, they seem to be less precise. We tried to simplify this complicated topic as much as possible in order to make it comprehensible to doctors and urologists that are not as familiar with it, as well as encourage them to actively participate in ongoing research.

Xpert bladder cancer monitor in surveillance of bladder cancer: Systematic review and meta-analysis

INTRODUCTION

There is a need for sensitive and specific biomarkers for detecting recurrences in patients with non-muscle invasive bladder cancer (NMIBC) on surveillance. Xpert bladder cancer (BC) monitor is the latest rapid in vitro qualitative test that detects expression of 5 mRNAs using a GeneXpert instrument. The primary aim of this review was to systematically review and pool the data regarding the diagnostic performance of Xpert BC in patients with NMIBC.

METHODS

Systematic literature search using 4 electronic databases (PubMed, EMbase, Scopus and Web of science) was performed. Pooled sensitivity, specificity and diagnostic odds ratio (DOR) were estimated using DerSimonian-Laird random-effects model. Standard Preferred Reporting Items for Systematic reviews and Meta-analysis guidelines were followed and the study protocol was registered with PROSPERO (CRD42021249762).

RESULTS

In this review, 11 prospective studies with 2,896 patients were included. Pooled sensitivity and specificity for Xpert BC were 73% (95% confidence interval (CI) 65%-80%) and 77% (95% CI 69%-84%) respectively. Area under curve (AUC) for Xpert BC monitor was 0.81 (0.78-0.84) respectively. Subgroup analysis from 7 studies for patients with high-grade recurrence revealed sensitivity, specificity and AUC of 0.86 (0.77-0.92), 0.78 (0.75-0.81) and 0.87 (0.84-0.90) respectively. Similar analysis for patients with low-grade recurrence revealed sensitivity, specificity and AUC of 0.58 (0.47-0.68), 0.79 (0.75-0.82) and 0.79 (0.75-0.82) respectively.

CONCLUSION

Xpert BC monitor has overall acceptable diagnostic accuracy. Sensitivity is higher for high-grade disease for detecting recurrences in patients with NMIBC on surveillance.

Can repeat biopsy be skipped after initial complete resection of T1 bladder cancer? The role of a novel urinary mRNA biomarker

OBJECTIVES

To prospectively investigate the role of a urinary mRNA biomarker (Xpert Test) after initial complete resection of T1 bladder cancer (BC) for the prediction of positive repeat biopsy for malignancy.

METHODS

Patients who underwent TURBT for NMIBC between September 2018 and April 2020 were included. Patients with benign pathology, incomplete resection, concomitant CIS/upper tract urothelial tumor or muscle invasive BC, were excluded. 2 to 6 weeks after primary TURBT, voided urine sample was retrieved for Xpert analysis and patients were scheduled for repeat biopsy. The primary outcome was to determine the role of positive Xpert test to predict positive repeat biopsy for malignancy.

RESULTS

During the study period, 254 patients met the study inclusion criteria of which 61 (24%) patients had recurrent NMIBC. Complete resection was censured by the presence of detrusor muscle in the specimen with documented T1 disease in all study participants. Xpert test was positive in 128 patients; of whom 85 (66.4%) showed positive repeat biopsy (HR=6.2, 95%CI=3.46-9.4, P = 0.002). The sensitivity, specificity, positive and negative predictive values of Xpert test for repeat biopsy were 85.9% (95%CI: 82-89), 72.3% (95%CI: 68-76), 66.4% (95%CI: 62-71) and 88.9% (95%CI: 85-94), respectively. On median (range) follow up of 12(3-25) months, tumor recurrence was encountered in 84 (35%) patients. On multivariate Cox regression analysis, Xpert test was significantly associated with tumor recurrence (HR= 9.7, 95%CI=5-18, P <0.001).

CONCLUSIONS

Positive Xpert test after primary complete resection of T1 BC is significantly associated with positive repeat biopsy for malignancy. In addition, Xpert test is an independent predictor of early tumor recurrence. Xpert test might be applied after initial complete resection of NMIBC to minimize unnecessary repeat biopsy with potential saving of healthcare costs and reduction in patient morbidity.