Feb. 15, 2005 -- A new simple test may make it easier to detect bladder cancer. Results can be calculated in less than an hour, before a patient even leaves the doctor's office.
However, the test doesn't single-handedly tell patients whether they have bladder cancer. No method perfectly diagnoses the disease, so doctors use several screening tools. The new test would be one more way to check for bladder cancer, the fifth most common cancer in America.
Like many cancers, early detection greatly improves the chances of survival. If identified early, 95% of bladder cancer patients survive at least five years -- a time period commonly used when discussing cancer survival.
However, if bladder cancer is found after it spreads beyond the superficial layers of the lining of the bladder, five-year survival rates drop significantly. Diagnosing bladder cancer, especially after seeing blood in the urine (the most common sign), is done by various methods, including directly visualizing the bladder through a flexible scope which has a tiny camera attached. The flexible cystoscopy can have problems with seeing the inside of the bladder, especially when there is inflammation.
Men are more at risk for bladder cancer than women. The risk is also greater for people older than 60 and those who have been exposed to environmental or occupational toxins such as exposure to aniline, a chemical used in medical and industrial dyes.
Smoking is the leading risk factor for bladder cancer. Cigarette smoking doubles bladder cancer risk and accounts for 50% of the bladder cancer deaths in men and 30% in women. The numbers are cited by experts including H. Barton Grossman, MD, of the urology department at the M.D. Anderson Cancer Center in Houston.
How Expensive Is the New Test?
Looking for ways to improve bladder cancer detection, Grossman and colleagues studied a new urine test. Their findings appear in the Journal of the American Medical Association's Feb. 16 issue.
The new test screens for elevated levels of a urine protein called NMP22. The protein is the only tumor marker approved by the FDA to help in the initial diagnosis of bladder cancer.
Other urine tests aren't specific to cancer or need special lab tests. They're also expensive, say the researchers.
The new test takes just four drops of urine. Within 30 to 50 minutes, results are available.
More than 1,300 people at high risk of developing bladder cancer took the new test in Grossman's study. They also got standard screening tests including cystoscopy.
Bladder cancer was diagnosed in 79 patients who were about 66 years old, on average. Three times as many men as women had bladder cancer.
The NMP22 test was positive in 44 of those cases. That was much better than the other urine tests which look for cancer cells, only 12 of which were positive. The new test also flagged four cancers that weren't seen via scope, including three cases in which the cancer had spread.
The new test could enhance, not replace, cystoscopy, say the researchers. It's also less expensive than the other urine tests. The new test cost $24, compared to $56 for average Medicare reimbursement for the other urine tests, say the researchers.
The new test should be tried on different groups of patients, researchers conclude.