Urine test helps detect 99 percent of recurring bladder cancers
A simple urine test that can be interpreted in a doctor's office can help detect nearly all recurrences of bladder cancers with a higher accuracy rate than conventional laboratory analysis of urine tests.
The BladderChek test, used in conjunction with a diagnostic scope, detected 99 percent of recurring bladder cancers.
The BladderChek test, which requires four drops of urine, detects elevated levels of the nuclear matrix protein NMP22, an indication of cancer even at early stages of the disease. A doctor or nurse can read the results in 30 to 50 minutes.
"You know the answer before the patient is out of your office," Barry Stein, at Brown Medical School says. " If the result is positive, and you didn't see anything from the cystoscopy, you would check to see if you missed something."
No single procedure is completely effective in detecting recurring bladder cancer, so physicians use a combination of methods – typically cystoscopy and a urine cytology test.
Cystoscopy, a minimally invasive procedure performed in a physician's office, enables physicians to view the wall of the bladder through a scope.
However, it may not detect very small tumors or tumors in the muscle or upper tract.
So in conjunction with the scope, physicians rely on cytology, a clinical analysis of a urine sample. The process can take a week or more, and requires expert interpretation. The analysis identifies changes in intact cells, but its sensitivity is dependent on the size and shape of the tumor.
In this study, 668 patients with a history of bladder cancer provided a urine sample before undergoing cystoscopy during follow-up visits with their physician.
The urine sample was analyzed with urine cytology, and with the BladderChek test.
Bladder cancer was identified in 103 patients.
Cytoscopy alone detected 94 cancers, and the BladderChek test detected 8 of 9 cancers that were not seen through the scope – 7 of them life-threatening.
The urine cytology only detected 3 of the 9 cancers.
Cystoscopy alone detected 91.3 percent of cancers. When cystoscopy was used with conventional urine analysis, the detection rate was 94.2 percent; when it was used with the BladderChek test, detection was 99 percent.
An accurate urine test could reduce the number of cystoscopies a patient undergoes, Stein says. While not painful, the procedure can be uncomfortable. By contrast, the BladderChek test is similar to a pregnancy test and gives objective results – if cancer is detected, a purple line appears.
The study has demonstrated that one day a simple urine test might replace cystoscopies.
. Source: American Medical Association, 2006
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