EPCA -2 Test for Prostate Cancer
In 2007, Dr. Getzenberg and a team of Hopkins researchers published an article in journal Urology in which they introduced evidence that EPCA-2 testing was more accurate than PSA in identifying prostate cancer. EPCA (early prostate cancer antigen) is a protein that is present in the blood in higher amounts in men who have prostate cancer than in men without cancer. Thus far EPCA seems to be more prostate-cancer specific than PSA, and if this is true, the test could reduce unnecessary biopsies and the over diagnosis and over treatment of prostate cancer. (Johns Hopkins Health Alert)
Getzenberg and his team determined that EPCA-2 levels of 30 nanograms per milliliters or higher were considered to indicate a risk for prostate cancer. They then measured EPCA-2 levels in the blood of 330 patients in various groups: men with normal PSA levels and no evidence of prostate cancer, men with elevated PSA levels but who had negative biopsies, men with BPH, men with prostate cancer and normal PSA levels, and various other groups. The researchers found that the EPCA-2 test was negative in 97 percent of the patients who did not have prostate cancer. In contrast, a multi-center study published in 2003 in the Journal of Urology noted that PSA levels between 4 and 10 nanograms per milliliter were accurate in identifying patients without prostate cancer only 19 percent of the time.
As of October 2009, some controversy surrounding Dr. Getzenberg and his EPCA-2 test arose when a biotechnology company in Washington state claimed he had concocted his test results. Getzenberg noted in a September 10 article that he is continuing with his research and that he and his team are moving “aggressively” to make the EPCA-2 biomarker available to men who have prostate cancer and for men who need to be tested for the disease. (PSA Rising)
PCA3 Test for Prostate Cancer
In Europe, clinicians have access to another test for prostate cancer that is an alternative to PSA. Called the PCA3 assay, this test detects the over-expression of a gene called PCA3 in urine. According to the maker of the PROGENSA PCA3 assay, research has shown that PCA3 is highly evident in the vast majority of men who have prostate cancer, indicating that this gene may be a useful indicator for the disease. Preliminary data indicate that the PCA3 test is more specific to prostate cancer than is PSA, which means less possibility of false positive results. As of May 2010, however, the PROGENSA PCA3 assay was still under development in the United States and had not been granted approval for marketing by the Food and Drug Administration.
New Blood Test
An ultrasensitive blood test that can identify a single cancer cell among a billion healthy cells may be available in the near future. The presence of stray cancer cells in the bloodstream means that a tumor has spread or probably will. Studies of the experimental blood test will begin in 2011. Physicians say they want to use the test to predict the best treatments for any given patient’s cancer and to determine whether those treatments are working. The blood test uses a microchip that looks like a lab slide covered in 78,000 minute posts coated with antibodies that bind to tumor cells. When blood passes across the chip, cancer cells stick and stains make them glow for easy detection.
Use of this blood test could avoid painful tissue sampling and could allow physicians a better and faster way to monitor patients rather than use imaging scans. Several facilities, including Mass General, Sloan-Kettering, University of Texas M.D. Anderson Cancer Center, and Dana-Farber Cancer Institute in Boston will be using the test in 2011 as part of a grant.
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