So says a study in The Journal of the American Medical Association. The researchers included H. Barton Grossman, MD, of the University of Texas M.D. Anderson Cancer Center.
The test, called BladderChek, screens urine for high levels of a protein called NMP22. Results are available within an hour, without extra lab work or special training for medical staff.
The test enhances -- but doesn't replace -- other screening methods, the researchers write.
'Good News for Patients'
Barry Stein, MD, worked on the study and commented on it in a news release.
"This is good news for patients," says Stein, a professor of urology at Brown Medical School and surgeon-in-chief of urology at Rhode Island Hospital in Providence, R.I.
"If you have been treated for bladder cancer and are being monitored for recurrence, the accuracy of your diagnosis is extremely important," Stein continues.
Stein says it's too soon to know if the BladderChek test should be used on its own, replacing other screening methods.
"We need to do further research," he says. "But if a test is developed that is effective as a standalone, that would be a real benefit."
Watching for Recurrence
More than half a million people in the U.S. have had bladder cancer, making it the country's fifth most common cancer, write Grossman and colleagues.
The chances of getting bladder cancer more than once are high -- about 50% to 90%, depending on the cancer's stage, grade, and original tumors, the researchers note. With odds like that, rigorous, repeated screening is recommended to check for recurrences.
The main test, called cystoscopy, uses a tiny scope to examine the inside of the bladder and is considered the gold standard. Another test, called cytology, checks urine for abnormal changes in intact bladder cells.
Cytology's lab work takes time and the test isn't always as sensitive as doctors would like, especially with low-grade or early cancers, write the researchers. They note that no single test is flawless, so more than one method is usually used.
New Test Proved Helpful
Grossman's study included 668 people who had had bladder cancer. All participants got all three tests -- cystoscopy (the scope), cytology (the old urine test), and the BladderChek test. The tests were done at 23 sites across the U.S.
A total of 103 people were found to have bladder cancer recurrences. The BladderChek test and cystoscopy -- taken together -- were best at spotting bladder cancer's return.
Cystoscopy alone showed 91% of the bladder cancers. But the scopes missed nine cancers. Those cases spanned several test sites, so they weren't one office's faulty work.
The BladderChek test flagged eight of those nine cancers, including seven that were particularly aggressive. The old urine test (cytology) only spotted three of those cancers, the study shows.
The BladderChek test wasn't perfect. In some cases, it could prompt false-positive results, the researchers write. Because participants were already scheduled for cystoscopy, none needed extra procedures.
Other Tests in the Works
In October 2005, Italian researchers reported promising results from another.
That test screens urine for an enzyme called telomerase. High telomerase levels may indicate bladder cancer, the Italian researchers reported in The Journal of the American Medical Association.
Telomerase tests "have shown good results in early trials but are still in the investigational stage and are not approved for clinical use," write Grossman and colleagues.
They add other tests are also in development but lack FDA approval and still require the time (and expense) of lab testing. BladderChek already has FDA approval for use in diagnosis and screening for bladder cancer, the researchers note.
Last year, Grossman and colleagues reported in The Journal of the American Medical Association that thedid a good job of identifying people in a smaller study who did and didn't have bladder cancer.
Both of their studies were backed by Matritech Inc., which makes the BladderChek test.