A study published in the July 2006 edition of Journal of Urology has shown that UroVysion, a DNA-based urine test that detects important genetic changes in bladder cells, has almost twice the sensitivity of conventional urine cytology tests, the current gold standard, as an aid for the initial diagnosis of bladder cancer in patients with hematuria (blood in urine) suspected of having bladder cancer. Sensitivity refers to the likelihood that a patient with bladder cancer will have a positive test result and is a standard indicator of the predictive value of a diagnostic test.
According to the authors of the study, hematuria is the symptom most commonly associated with bladder cancer. But because bladder cancer only accounts for about 10 per cent of patients with hematuria, a delay between those first symptoms and diagnosis is not only common, it has been shown to adversely affect patient outcomes.
This prospective, blinded study involved 497 eligible patients with an average age of 63 from 23 clinical sites throughout the United States and Canada. All patients had confirmed hematuria within three months of enrolment. The results showed that UroVysion detected 69 per cent of bladder tumours, while cytology detected 38 per cent. When low grade, low stage (i.e., Ta Grade 1) tumours were excluded, UroVysion detected 83 per cent of the cases, while cytology detected only 50 per cent. Further, the "negative predictive value" or probability that negative UroVysion results were not associated with bladder cancer in this group was 98.5 per cent.
"These data certainly argue strongly for the use of the UroVysion assay, particularly if urine cytology results are negative," said Michael Sarosdy, M.D., of San Antonio, Texas, a urologic oncologist and lead investigator of the UroVysion study.
UroVysion is the first and only test approved by the US Food and Drug Administration that uses DNA probes to identify up to four chromosomal abnormalities frequently associated with bladder cancer. UroVysion is also known as "molecular cytology" because it assesses both morphologic cellular changes of conventional cytology and molecular DNA changes. Intended as an aid to current diagnostic procedures, its unique ability to detect chromosomal change can provide deeper insight to the clinician in monitoring for tumour recurrence in patients previously diagnosed with bladder cancer and in the initial diagnosis in patients with hematuria suspected of having bladder cancer. UroVysion is based on Abbott's proprietary fluorescence in situ hybridization (FISH) technology.
"This study further confirms the clinical benefit and superiority of UroVysion over the gold standard of cytology as an aid in the detection of bladder cancer," said Timothy Stenzel, M.D., Ph.D., medical director, Abbott Molecular. "Because of its balance of high sensitivity and specificity, and its unique ability to detect chromosomal change, UroVysion is an important test, particularly for detection of high-risk bladder cancers."