Comprehensive PSA Test for Most Prevalent Male Cancer

Plainview, NY (PRWEB) April 10, 2008 -- For decades the "gold standard" in testing for prostate cancer - the most prevalent and deadly male cancer - has been the Total PSA screening. Yet, simply measuring the amount of PSA in the bloodstream has its drawbacks. Chief among them is the fact that elevated serum PSA can be caused by a variety of factors, leading to a significant percentage of false positive results. What's more, the benchmark level where clinicians consider further testing can shift based on prevailing research and professional experience. The normal level of Total PSA is 0-4 ng/ml, but according to new recommendations the cut-off should be at 2.5 ng/ml. Most difficult to make a decision about diagnosis and further testing in the so called "grey zone", when PSA levels are between 4 and 10 ng/ml. Above 10 ng/ml Total PSA biopsy is always performed.

However, researchers have discovered a new, more comprehensive way to measure PSA in the bloodstream that can lead to more accurate diagnosis. According to Zsuzsanna Vegh-Goyarts, Ph.D., Head of Flow Cytometry and Tumor Markers at Acupath Laboratories, a newer and more accurate test measures the ratio between "free" PSA and total PSA in the bloodstream to determine how likely it is that a malignant prostate tumor is present.

"We now know that there are two types of PSA that can be present in the bloodstream," Dr. Vegh-Goyarts explains. "There is 'free' PSA which is not bound to any other proteins, and there is complexed PSA, which is bound to one of a number of protective blood proteins which inactivate the PSA molecule." Dr. Vegh-Goyarts notes that recent research shows a strong correlation between the percentage of "free" PSA in the bloodstream and the presence of a malignant prostate tumor. Free PSA is measured only if the total PSA level is in the "grey zone" (in our laboratory between 2.5 and 10 ng/ml). If the percentage of free PSA is low, there is a much greater likelihood that cancer is present. If it is high, the cause of the elevated total PSA is not cancer, and biopsy is not necessary. Of course final diagnosis always determined in the view of all clinical data and test results.

PSA (Prostate Specific Antigen) is an enzyme released by the prostate gland, a tubular gland located near the base of the penis. PSA serves to lubricate the urethra and helps activate sperm. Dr. Vegh-Goyart points out, "PSA finds its way into the bloodstream in only trace amounts, and it serves no function in the blood at all, so when we find elevated levels of serum PSA, we know there is a medical issue." In addition to prostate cancer, high PSA levels in the bloodstream can be caused by Benign Prostate Hyperplasia (BPH) - an enlargement of the prostate gland - prostate inflammation, or normal fluctuations in PSA levels.

"The Free PSA Test is an advantage (for those men who present with a "grey zone" Total PSA screening result), but otherwise show no risk for prostate cancer," Dr. Vegh-Goyarts explains. "We can (perform the Free PSA Test to further establish the likelihood of whether or not a tumor is present before considering a prostate biopsy - which can be expensive, uncomfortable and anxiety-provoking for the patient," she adds. In fact, in the benchmark study on Free PSA Testing published in the Journal of the American Medical Association in May 1998, researchers from Washington University Medical School in St. Louis, MO were able to reduce by 20% the number of unnecessary biopsies among 733 men with elevated PSA levels. "As with any surgical procedure, a prostate biopsy carries certain risks and can be contraindicated in certain situations, so having an additional level of screening to provide a more accurate picture is very beneficial," Dr. Vegh-Goyarts notes.

Prostate Cancer Continues to Plague Older Men

Prostate cancer is the most prevalent male (non-skin) cancer, and according to the American Cancer Society, more than 186,000 new cases will be diagnosed this year alone. Nearly 30,000 men die of the disease each year. "In order to reduce these numbers, all men over the age of 50 - and younger men who have genetic risk factors - should have an annual prostate screening," Dr. Vegh-Goyarts advises. In addition, she concludes that men who experience urinary changes such as difficult or frequent urination, getting up frequently at night to urinate, urgent urination during the day or leakage for several minutes after urinating should consult their primary care physician or urologist.

Free and Total PSA immunoassays are soon available at Acupath Laboratoryes Inc.

About Dr. Zsuzsanna Vegh-Goyarts, PhD

Dr Vegh-Goyarts has a Ph.D.in Immunology and extensive training and experience in the field of tumor biology and immunology. She spent her postdoctoral years in prestigious research institutes such as the Tumor Biology Department of the Karolinska Institute in Stockholm, Sweden, and the Immunology Department of Albert Einstein College of Medicine, NY. Before joining Acupath she worked as an Assistant Professor in immunology research at SUNY Stony Brook and she was trained in Clinical Immunology at Stony Brook UHMC. Dr Vegh-Goyarts has 40 peer reviewed publications of her own work. She holds a Certificate of Qualification in Diagnostic Immunology and all four areas of Cellular Immunology from the New York State Department of Health. www.acupath.com

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