TUESDAY, Jan. 17 (HealthDay News) -- A new study further validates the use of a simple, in-office test to catch recurrences of bladder cancer.
The test, which measures a urinary protein called NMP22, is already approved by the U.S. Food and Drug Administration and is used in conjunction with another test called cystoscopy.
"This is real evidence that there is a benefit to using NMP22 plus cystoscopy," said Dr. Michael A. Palese, director of minimally invasive urology at Mount Sinai Medical Center in New York City. "This study should help the test gain more widespread use, in combination with cystoscopy."
"This is the first major publication of this test used in this setting," added study author Dr. H. Barton Grossman, deputy chairman of the department of urology at M.D. Anderson Cancer Center in Houston. "This test performs pretty well, it's cost-effective, and the results are available on short order. It's good for physicians to be aware of the information to see if they want to use it."
The study appears in the Jan. 18 issue of the Journal of the American Medical Association.
Bladder cancer is the fifth most common type of cancer in the United States and also has high recurrence rates, ranging from 50 percent to 90 percent, the study noted. Because individuals who have had bladder cancer need to be followed for the rest of their lives, the expense of the disease from diagnosis to death is the highest of all cancers in this country, ranging from $96,000 to $187,000 per patient.
"Overall rates of recurrence in bladder cancer are at least 50 percent, one out of two," Grossman said. "It doesn't mean it's necessarily going to be fatal or life-threatening, but it's important to detect it reasonably early so it can be treated. If it's not picked up early, it has the potential to turn into a life-threatening disease."
Currently, different tests are used to check for recurrences. Cystoscopy, a visual inspection of the bladder with a medical instrument usually done in the doctor's office, can miss some cancers. It is often used with cytologic analysis, or analysis of cells voided in the urine, but this is also not perfect. NMP22 is a protein produced in higher concentrations by malignant cells.
The current study was a fairly large one, involving 668 patients at 23 different practice centers. All participants had a history of bladder cancer. The actual tests used were provided by Matritech Inc., the manufacturer.
Cystoscopy on its own identified 91.3 percent of the cancers. When the NMP22 test was added, 99 percent of the cancers were picked up. The NMP22 test found eight out of nine cancers that were not picked up during the initial cystoscopy, including seven that were high-grade.
The NMP22 test has the advantages of being simple, easy and cost-effective.
"It's easier in that you can do it in a physician's office," Palese said. "We use a dipstick and you can get an answer right away, as opposed to sending the cytology test to a lab."
In addition, cytology tests are more likely to come back positive when the cancer is high-grade, and it's more useful to find recurrent bladder cancer when it's low-grade and can be more easily treated, Palese pointed out.
The NMP22 test is also used as a screening tool to see if people have first-time bladder cancer and performs better than cytology, Grossman added.
More information
For more on bladder cancer, head to the American Cancer Society.
