Validation of an mRNA-based Urine Test for the Detection of Bladder Cancer in Patients with Haematuria

BACKGROUND

In patients with haematuria, a fast, noninvasive test with high sensitivity (SN) and negative predictive value (NPV), which is able to detect or exclude bladder cancer (BC), is needed. A newly developed urine assay, Xpert Bladder Cancer Detection (Xpert), measures five mRNA targets (ABL1, CRH, IGF2, UPK1B, and ANXA10) that are frequently overexpressed in BC.

OBJECTIVE

To validate the performance of Xpert in patients with haematuria.

DESIGN, SETTING, AND PARTICIPANTS

Voided precystoscopy urine specimens were prospectively collected at 22 sites from patients without prior BC undergoing cystoscopy for haematuria. Xpert, cytology, and UroVysion procedures were performed. Technical validation was performed and specificity (SP) was determined in patients without BC.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Test characteristics were calculated based on cystoscopy and histology results, and compared between Xpert, cytology, and UroVysion.

RESULTS AND LIMITATIONS

We included 828 patients (mean age 64.5 yr, 467 males, 401 never smoked). Xpert had an SN of 78% (95% confidence interval [CI]: 66-87) overall and 90% (95% CI: 76-96) for high-grade (HG) tumours. The NPV was 98% (95% CI: 97-99) overall. The SP was 84% (95% CI: 81-86). In patients with microhaematuria, only one HG patient was missed (NPV 99%). Xpert had higher SN and NPV than cytology and UroVysion. Cytology had the highest SP (97%). In a separate SP study, Xpert had an SP of 89% in patients with benign prostate hypertrophy and 92% in prostate cancer patients.

CONCLUSIONS

Xpert is an easy-to-use, noninvasive test with improved SN and NPV compared with cytology and UroVysion, representing a promising tool for identifying haematuric patients with a low likelihood of BC who might not need to undergo cystoscopy.

PATIENT SUMMARY

Xpert is an easy-to-perform urine test with good performance compared with standard urine tests. It should help identify (micro)haematuria patients with a very low likelihood to have bladder cancer.

Prospective Validation of an mRNA-based Urine Test for Surveillance of Patients with Bladder Cancer

BACKGROUND

A fast, noninvasive test with high sensitivity (SN) and a negative predictive value (NPV), which is able to detect recurrences in bladder cancer (BC) patients, is needed. A newly developed urine assay, Xpert Bladder Cancer Monitor (Xpert), measures five mRNA targets (ABL1, CRH, IGF2, UPK1B, and ANXA10) that are frequently overexpressed in BC.

OBJECTIVE

To validate Xpert characteristics in patients previously diagnosed with non-muscle-invasive BC.

DESIGN, SETTING, AND PARTICIPANTS

Voided precystoscopy urine samples were prospectively collected at 22 sites. Xpert, cytology, and UroVysion were performed. If cystoscopy was suspicious for BC, a histologic examination was performed. Additionally, technical validation was performed and specificity was determined in patients without a history or clinical evidence of BC.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Test characteristics were calculated based on cystoscopy and histology results, and compared between Xpert, cytology, and UroVysion.

RESULTS AND LIMITATIONS

Of the eligible patients, 239 with a history of BC had results for all assays. The mean age was 71 yr; 190 patients were male, 53 never smoked, and 64% had previous intravesical immunotherapy (35%) or chemotherapy (29%). Forty-three cases of recurrences occurred. Xpert had overall SN of 74% (95% confidence interval [CI]: 60-85) and 83% (95% CI: 64-93) for high-grade (HG) tumors. The NPV was 93% (95% CI: 89-96) overall and 98% (95% CI: 94-99) for HG tumors. Specificity was 80% (95% CI: 73-85). Xpert SN and NPV were superior to those of cytology and UroVysion. Specificity in non-BC individuals (n=508) was 95% (95% CI: 93-97).

CONCLUSIONS

Xpert has an improved NPV compared with UroVysion and cytology in patients under follow-up for BC. It represents a promising tool for excluding BC in these patients, reducing the need for cystoscopy.

PATIENT SUMMARY

Xpert is an easy-to-perform urine test with good performance compared with standard urine tests. It should help optimize the follow-up of recurrent bladder cancer patients.