Ouchless Bladder Cancer Test Shows Promise
May be used for intestinal cancers, too
By Edward Edelson
THURSDAY, Oct. 28 (HealthSCOUT) -- A simple urine test that could replace the current intrusive, uncomfortable testing method for bladder and urinary tract cancers has passed its first human trial and has moved rapidly into larger studies, British researchers report.
The test also could be used to diagnosis and screen for all malignancies of the urinary and intestinal tracts, says Dr. Gareth Williams, whose findings are reported in the Oct. 29 issue of the British journal The Lancet.
The test looks for specific proteins made by rapidly dividing cancer cells but not by normal cells. "We take the urine and screen for these replication proteins that are not present in normal patients," Williams says. "If the proteins are present, it indicates the presence of cancer with over 95 percent sensitivity and specificity."
Cancer of the urinary tract is difficult to treat, and it often recurs after treatment, Williams says. The only way doctors now can test for recurrence is cystoscopy, in which the patients is anesthetized and a rigid tube is inserted into the urinary tract for a visual inspection.
"This is an expensive and difficult procedure, so screening for recurrence of bladder cancer is not often done," he says.
If the test fulfills its promise, it could be valuable in cancer treatment, says Dr. Robert Smith, director of cancer screening for the American Cancer Society.
"This is exactly the kind of finding that offers great potential for detecting cancers earlier," Smith says. "The potential for a test like this to measure early bladder cancer could be very useful for those who need surveillance, such as patients who have already had surgery."
A telltale protein
The Lancet report says the test was used to detect abnormal Mcm proteins in eight patients with bladder cancer and 28 patients who did not have cancer. The proteins were found in all eight cancer patients and one of the 28 cancer-free subjects. That patient had an ulcer caused by infection, where a false-positive result would be expected, the report says.
"We are now screening a larger number of patients, hundreds of them," Williams says. "These are people who come to the urological clinic because of blood in their urine. We are doing cystoscopy as well as a biochemical readout and hope to have results in the next three to four months."
The Wellcome Trust/Cancer Research Campaign Institute in Cambridge, where Williams is a clinician scientist, is negotiating with a number of companies to make the test available commercially if the trials succeed, he says.
"Most hospital laboratories could do it," he says. "Hopefully it could be done by a machine. If the test showed the presence of these proteins, then you would do cystoscoping. These are the only patients you want to scope."
If the larger trial produces the hoped-for results, the test would be used first on patients who undergo surgery for urinary tract cancers, Williams says. But because the tissue that lines the urinary tract also lines the colon, the prostate and other parts of the intestinal tract, the abnormal protein would be a marker for cancers in any of those organs, he says.
"While the current trial is interesting in its own right, it can be used as a test bed for other systems of the intestinal tract," Williams says. "The colon would be the big one to go for, then the prostate and the cervix. We are preparing a similar paper on cancer of the cervix."
The long-term hope is for a standard urine test that would detect cancers of the intestinal tract at their earliest, most treatable stage, he says.
But that hope will not be validated until a lot more testing is done, warns Smith. Other tests have proved valuable in cancer treatment but did not work out as screening tools, he says.
What To Do
About 54,000 Americans will develop bladder cancer every year, and about 12,000 will die of the disease. It strikes men three times more often than women. Since smoking causes bladder cancer as well as other malignancies, you have yet another reason to give up cigarettes.
The survival rate for bladder cancer is high -- if it's caught early, so it's no surprise that doctors want the best early screening possible. If you see blood in your urine, consult a doctor at once. Go to the American Cancer Society for more on this disease.