Longitudinal follow-up and performance validation of an mRNA-based urine test (Xpert® Bladder Cancer Monitor ) for surveillance in patients with non-muscle-invasive bladder cancer.

OBJECTIVE: To evaluate the performance of the Xpert Bladder Cancer Monitor (Xpert; Cepheid, Sunnyvale, CA, USA) test as a predictor of tumour recurrence in patients with non-muscle-invasive bladder cancer (NMIBC). PATIENTS AND METHODS: Patients (n = 429) undergoing surveillance for NMIBC underwent Xpert, cytology, and UroVysion testing. Patients with a positive Xpert and a negative cystoscopy result (positive-negative [PN] group, n = 66) and a control group of double negative patients (negative Xpert and cystoscopy results [NN] group) were followed for 12 months (±90 days). RESULTS: Histology-confirmed recurrences were detected in 58 patients (13.5%). Xpert had an overall sensitivity of 60.3% and a specificity of 76.5%. The sensitivity for high-grade (HG) cancer was 87% with a negative predictive value (NPV) of 99%. Urine cytology showed an overall sensitivity of 23.2% (47.6% sensitivity for HG tumours) and a specificity of 88.3%. In the PN group, 32% (n = 21) developed a recurrence within 12 months, 11 of which were HG tumours. In the NN control group, 14% (n = 9) developed a recurrence and only two were HG tumours. The hazard ratio for developing recurrence in the PN group was 2.68 for all tumours and 6.84 for HG cancer. CONCLUSIONS: The Xpert test has a high sensitivity for detecting the recurrence of cancer and a high NPV for excluding HG cancer. In addition, the data suggest that patients with a positive Xpert assay in the setting of negative cystoscopy are at high risk for recurrence and need close surveillance.

Development of a 90-Minute Integrated Noninvasive Urinary Assay for Bladder Cancer Detection.

PURPOSE: Despite suboptimal sensitivity urine cytology is often performed as an adjunct to cystoscopy for bladder cancer diagnosis. We aimed to develop a noninvasive, fast molecular diagnostic test for bladder cancer detection with better sensitivity than urine cytology while maintaining adequate specificity. MATERIALS AND METHODS: Urine specimens were collected at 18 multinational sites from subjects prior to cystoscopy or tumor resection, and from healthy and other control subjects without evidence of bladder cancer. The levels of 10 urinary mRNAs were measured in a training cohort of 483 subjects and regression analysis was used to identify a 5-mRNA model to predict cancer status. The performance of the GeneXpert® Bladder Cancer Assay, an assay labeled for investigational use only to detect the 5 mRNAs ABL1, CRH, IGF2, ANXA10 and UPK1B, was evaluated in an independent test cohort of 450 participants. RESULTS: In the independent test cohort the assay ROC curve AUC was 0.87 (95% CI 0.81-0.92). At an example cutoff point of 0.4 overall sensitivity was 73% while specificity was 90% and 77% in the hematuria and surveillance patient populations, respectively. CONCLUSIONS: We developed a 90-minute, urine based test that is simple to perform for the detection of bladder cancer. The test can help guide physician decision making in the management of bladder cancer. Additional evaluation in a prospective study is needed to establish the clinical usefulness of this assay.

Multicenter beta trial of the GeneXpert enterovirus assay.

The GeneXpert Dx system (Cepheid, Sunnyvale, CA) is a fully integrated and automated nucleic acid sample preparation, amplification, and real-time detection system. It consists of an instrument, a personal computer, and disposable fluidic cartridges. The analytical sensitivity and specificity of the GeneXpert enterovirus assay (GXEA) were determined with a panel of 63 different enterovirus serotypes and 24 other microorganisms, respectively. The potential for blood, hemoglobin, white blood cells, and excess protein to interfere with the assay was also assessed. The performance parameters of the GXEA were determined at three sites with 102 cerebrospinal fluid (CSF) samples obtained from patients with suspected meningitis. All samples were tested for enterovirus RNA with locally developed reverse transcription-PCR (RT-PCR) assays at the trial sites and with a seminested RT-PCR and an analyte-specific reagent (Cepheid) at a reference laboratory. The 5' nontranslated region was the target for all of the PCR assays except the seminested RT-PCR, which amplified a VP1 sequence. The VP1 amplicon was sequenced to identify the enterovirus types. Consensus reference laboratory RT-PCR results were used to classify cases of enteroviral meningitis. The GXEA detected all of the enterovirus serotypes and none of the other microorganisms tested except rhinovirus 16. The assay was unaffected by moderate amounts of blood or blood components. Thirty-six (35%) of the CSF samples tested had at least one positive PCR result. Eleven different enterovirus serotypes were identified in the positive samples. The GXEA had a sensitivity of 97.1% (95% confidence interval [CI], 84.7 to 99.9%) and a specificity of 100% (95% CI, 94.6 to 100%) for the diagnosis of enteroviral meningitis.