New Prostate Cancer Urine Test
July 13, 2017
Prostate Specific Antigen (PSA) screening is the universal standard for early detection of prostate cancer in men. The medical community, and even the press, routinely urge men to begin PSA testing at age 50, and even earlier age 40 for high risk men, including African Americans or those with a family history of prostate cancer. Dr. David Samadi, Vice Chairman, Department of Urology, and Chief of Robotics and Minimally Invasive Surgery at The Mount Sinai Medical Center, believes compliance with these early testing guidelines can save the lives of men diagnosed with prostate cancer. Now, another tool may soon be available to aid in the early detection and treatment of prostate cancer.
Researchers at the University of Michigan Health System are exploring a new urine test designed to identify two genetic markers in men. These bio-markers, TMPRSS2:EG and PCA3, are known to be present in prostate cancer patients. The first, caused by two genes switching places and then fusing together, is believed by some to be the cause of prostate cancer; however, it only occurs in approximately half of cancer patients. Therefore, screening for the second genetic marker, PCA3, is included in the urine test. "I am a huge proponent of early PSA testing," says robotic prostatectomy and robotic surgery expert Dr. Samadi, "so I'm very encouraged to see research that may result in additional testing resources. Strengthening our prostate cancer screening ability is the first step toward eliminating prostate cancer."
The research surrounding the new urine test is designed to determine its ability to stratify men diagnosed with prostate cancer. More than one million prostate biopsies are performed annually in the Unites States, most often as a follow-up to the detection of elevated PSA levels. Like other medical tests, PSA screenings can produce false results, so it is possible that some biopsies are performed on men who don't actually have raised PSA levels. Researchers believe this new, non-invasive test may reduce the immediate need for biopsies in men found to have low levels of the prostate cancer genetic markers. "I'm hopeful that this new research may help us refine prostate cancer screening in the future and I'm very interested in following its progress," Dr. Samadi said. "In dealing with my prostate cancer patients, I always err on the side of caution," he added. "PSA screening, followed by a prostate biopsy when needed, is currently the best course of action for detecting prostate cancer early." Dr. Samadi has performed over 3,500 radical prostatectomy procedures and is an expert in robotic prostate surgery.
The study looked at 1,312 men with elevated PSA levels and subsequent prostate removals, comparing the results of their urine tests with those of their biopsies. The researchers believe that the correlations they found in the two test results indicate that the urine test will be an effective tool in detecting a man's prostate cancer risk. "Studies of these two genetic markers have been performed in the past," adds Dr. Samadi, "and there is evidence that combining such a test with the PSA blood test may result in a better prediction of prostate cancer." Dr. Samadi cautions that this new research does have one important limitation. "African American men experience the highest incidence and mortality rate of men with prostate cancer. This study focused primarily on Caucasian men, so I do hope that research will be done soon on the effectiveness of the genetic marker urine test in this high-risk segment. I look forward to seeing those results."
San Diego based Gen-Probe is the maker of this genetic diagnostic test. Though the urine test has not yet been submitted to the FDA for approval, nor is it available to the public, the University of Michigan will soon begin using it.
Source: Robotioncology