PSA Rising, March 11 ? A new test under development by Tessera Diagnostics Inc., a Seattle company, could identify men with prostate cancer as much as five years earlier than current ways of diagnosing the disease, Pittsburgh researchers say.
The new test uses a protein called EPCA to detect changes in tissue that indicate the presence of early disease.
Robert Getzenberg, Ph.D., professor of urology, pathology and pharmacology at the University of Pittsburgh School of Medicine and co-authors published findings about the new test in April 2004 issue of the Journal of Urology. Getzenberg and a fellow author, Robert Materson, Ph.D., of Tessera Inc., declare a financial interest in development of the product.
The test for the EPCA protein, they say, could help to find prostate cancer in patients with elevated levels of prostate-specific antigen, or PSA, who otherwise would require repeat needle biopsies. It might also help limit the numbers of biopsies performed as part of subsequent routine evaluation for increased PSA.
PSA, a substance in the blood released by the prostate gland, is commonly used to check for signs of prostate cancer and other prostate problems.
"One of the problems with testing for levels of PSA as an indicator of prostate cancer is that PSA levels often fluctuate up and down, making it difficult to know for certain whether a man has prostate cancer without performing multiple biopsies over time," said Robert Getzenberg, Ph.D., senior author for this study, who is co-director of the Prostate and Urologic Cancer Program at the University of Pittsburgh Cancer Institute.
"By testing for EPCA in men with high levels of PSA, we may be able to detect the presence of prostate cancer earlier, before it is discoverable by biopsy, saving patients the fear and stress of repeat procedures and enabling us to treat the disease sooner."
EPCA is a marker protein that indicates the earliest changes that occur in cells during the development of cancer. In the study, Dr. Getzenberg and colleagues developed antibodies against EPCA to detect its presence in tissue.
They compared 27 non-diseased control tissue samples to 29 tissue samples from patients with prostate cancer who had initial negative biopsies.
They found that the samples from the negative biopsies of those patients who were eventually diagnosed with prostate cancer expressed EPCA and that EPCA was not expressed in tissue samples from individuals without disease.
They also found that EPCA was not only expressed in the tumor, but throughout the prostate in men with prostate cancer indicating its usefulness as a prognostic marker for prostate cancer.
Sensitivity of the test is reckoned to be 84% and specificity is 85%.
A multi-center study is currently underway to further assess the usefulness of EPCA and its possible use as a biomarker for prostate cancer.
The study was paid for by a grant from
Tessera Diagnostics Inc ., Seattle, Wash. Senior author is Robert Getzenberg, Ph.D., professor of urology, pathology and pharmacology at the University of Pittsburgh School of Medicine. Co-authors include Rajiv Dhir, Ph.D., Barbara N. Vietmeier, Julie Arlotti, Ph.D., Marie Acquafondata, Ph.D., and Douglas Landsittel, Ph.D., of the University of Pittsburgh School of Medicine and Robert Materson, Ph.D., of Tessera Inc.
Abstract: The Journal of Urology : Volume 171(4) April 2004 pp 1419-1423
EARLY IDENTIFICATION OF INDIVIDUALS WITH PROSTATE CANCER IN NEGATIVE BIOPSIES
University of Pittsburgh Medical Center
This page compiled by J. Strax. Last updated April 22, 2004
Earlier story Prostate Cancer Marker, EPCA, Could Find Disease Five Years Earlier May 11, 2004
This page reported by J. Strax, last updated May 15, 2005
About Us | Content Policy/Disclaimer | Privacy Policy © 1997-2005 PSA Rising
