A Fox Chase Cancer Center researcher who has demonstrated that prostate and kidney cancer can be detected in the urine, now has published a study showing the detection of bladder cancer in urine. The research, supported in part by a grant from the Flight Attendants Medical Research Institute, is published in the March 15th issue of the journal Clinical Cancer Research.
Bladder cancer is the fourth most common male cancer in the Western world. There will be more than 44,6000 new cases of bladder cancer diagnosed in U.S. men this year and more than 15,600 new cases diagnosed in women As many as 25 percent of these cancers are diagnosed after the disease is advanced, leading to a poor prognosis.
The most common symptom of bladder cancer is blood in the urine (hematuria) however, hematuria often appears late in individuals with bladder cancer, and the majority of individuals with blood in their urine do not have bladder cancer. Currently, the most sensitive diagnostic test for bladder cancer is invasive and requires the insertion of a scope into the bladder. Non-invasive tests such as cytology and other urinary markers have significant limitations, particularly in detecting the disease early.
"New approaches to screen for bladder cancer are imperative," explains Paul Cairns, Ph.D., senior author of the study and recipient of a Flight Attendants Medical Research Institute Young Clinical Scientist Award. "An inexpensive, noninvasive, accurate and simple screening test such as a urine test could help accurately diagnose patients with clinical symptoms. Such a test also would be useful in individuals at high-risk of developing bladder cancers, including those who have been exposed to tobacco smoke. Furthermore, this test could detect early tumors before they become advanced, which would have a significant impact on a patient's prognosis."
For this study, researchers used a laboratory procedure to test the urine of 45 patients with bladder cancer prior to surgery. Thirty-nine (39) of the 45 tests showed gene changes in the urine that were identical to the gene changes found in the tumor samples taken at the time of surgery (87% sensitivity). Furthermore, a separate gene characteristic in the tumor DNA was always found to be the same in the matched urine DNA (100% specificity).
The researchers used a molecular DNA-based test called methylation-specific PCR (polymerase chain reaction) to detect genetic alterations that initiate and fuel the onset of cancer. The test searched for three cancer specific tumor-suppressor genes that were altered - causing them to falter in their critical role of preventing errant cell growth. These three genes are usually identified only after a pathologist's review of tumor tissue. Importantly, MSP was positive in 31 tissue samples whereas only 17 of 34 tissue samples examined had positive cytology. MSP detected almost all (26 of 28) of the early tumors included in the study.