TUESDAY, Oct. 25, 2005 (HealthDay News) -- A new test could be a much-needed early detection screen for bladder cancer, Italian researchers report.
The test measures levels of an enzyme called telomerase in urine, according to a study published in the Oct. 26 issue of the Journal of the American Medical Association.
Telomerase is an enzyme that repairs damage to chromosomes, cell components that contain genetic information. The enzyme is especially active in cancer cells, and the Italian researchers say bladder cancer patients had four times the normal level of telomerase in their urine compared to healthy patients.
The test "represents a promising and potentially important contribution to the early diagnosis of bladder carcinoma, particularly for high-risk subgroups," wrote researchers at Morgagni-Pierantoni Hospital, in Forli. But further trials are needed to confirm its value, they added.
"With Italian Ministry of Health Funding, we have already planned to use this test for risk subgroups," said Daniele Calistri, an oncologist member of the research team. The persons in the trial will be those at high risk of bladder cancer, such as smokers and workers exposed to cancer-causing chemicals on the job.
"We hope to have conclusive results showing the test's clinical usefulness within one year, and to conclude the study within two years," Calistri said.
A diagnosis of bladder cancer, which occurs in more than 60,000 Americans each year, now requires an expensive test that looks for cancer cells in urine as well as cystoscopy, an uncomfortable procedure in which doctors view the bladder using a tiny camera inserted into the urethra.
By contrast, the telomerase test "is noninvasive, inexpensive, easy to perform," the researchers noted. "One important advantage of this test is its proven ability to also identify low-grade tumors, which often escape detection," they said.
The Italian trial measure telomerase levels in 218 men, of whom 134 had been diagnosed with bladder cancer and 84 were healthy individuals. The results were measured in "arbitrary enzyme units," (AEU).
According to the researchers, healthy men's telomerase levels averaged 27 AEUs, compared to 112 for those with bladder cancer.
The test would not be used for routine screening of all persons, because of the relatively low incidence of bladder cancer in the population, Calistri said. Instead, it would be limited to high-risk groups -- most notably smokers, whose risk of bladder cancer is threefold that of nonsmokers, he said.
But the greatest value of the test could be for patients who have successfully been treated for bladder cancer, said Dr. John Phillips, the physician in charge of urologic oncology at Beth Israel Medical Center in New York City.
"This will be an important test in detecting recurrence of bladder cancer," Phillips said. "People who have been treated now require years of expensive follow-up. If that could be avoided by having one negative telomerase test, the test would be worthwhile. Right now we are not able to do that with any other test."
For more on bladder cancer, head to the American Cancer Society.