Washington, DC, May 16, 2011 — As physicians and researchers debate the merit of the prostate-specific antigen (PSA) test, questions have arisen about the test’s ability to accurately identify the presence of prostate cancer, as well as how the test may be interpreted and better used to determine which prostate cancers require treatment and which do not. New research presented at the 2011 AUA Annual Meeting will bring light to the innovative possibilities for the use of PSA. A special panel, to be held on Monday, May 16, 2011 at 9:00 a.m., will discuss with members of the media the following studies:
How Soon Can We Identify Men at High Risk for Prostate Cancer Death? An Early Surveillance Strategy for Prostate Cancer (#986): A single blood test before the age of 50 could predict a man’s long-term risk of prostate cancer death, according to research from Memorial Sloan-Kettering Cancer Center in New York and Lund University in Malmo, Sweden. Using data from the Preventive Project, a cardiovascular study enrolling men ages 33 to 50 between 1974 and 1986, and a combination of case-note review or death certificate data, researchers identified 141 men in the study who had subsequently died of prostate cancer. Nearly half (44 percent) of the deaths occurred in men whose PSA score fell in the top 10 percent (≥1.5 ng/ml). Researchers expanded their analysis to the top quartile of men, measuring free PSA and human glandular kallikrein 2 (hK2), and found that these markers helped to identify an additional 2.4 percent of deaths in the top 10 percent of risk. These data suggest that early analysis of PSA, free PSA and hK2 may provide critical insight into a man’s risk of developing aggressive, life-threatening disease, enabling urologists to better assess when early intervention may be necessary.
Can a Single PSA Measurement at Age 60-70 Years Identify Men Who Need No Further Prostate Cancer Testing? (#2025): Eliminating prostate cancer testing after the age of 60 may be an option for some men, but others could benefit from continued testing, according to new data being presented by Johns Hopkins researchers. Using data from the Baltimore Longitudinal Study of Aging, researchers identified 448 men with PSA measurements between the ages of 60 and 70, including 199 with a PSA less than 1 ng/ml. They reviewed PSA trajectory and its relationship to later diagnosis of prostate cancer (including high-risk disease, defined by PSA greater or equal to 20 ng/ml, Gleason 8-10 or confirmed prostate cancer death). In the 199 men with low PSA (median age of 61.9 at time of test), 13 were later diagnosed – four with significant disease. These data indicate that it may not be advisable to apply a universal cut-off point for PSA testing.
Possible Pitfalls in Using Prostate-Specific Antigen Velocity for Detection of Prostate Cancer (#2032): Prostate-specific antigen velocity (PSAV) can be a strong derivative in improving the performance of the PSA blood test as a marker for prostate cancer but has limited sensitivity and specificity, according to new data from researchers at Northwestern University. Researchers examined patients in two categories: those with elevated PSAV and no cancer on biopsy, and those with low PSAV with biopsy-detected cancer. Of those patients with low PSAV with biopsy-detected disease, 4.6 percent had a Gleason 8-10 tumor, 30 percent had slow-growing tumors with a Gleason score less than 6 and 54 percent had Gleason 7 tumors. Of those patients with elevated PSAV and negative biopsy, 58 percent were later diagnosed with biopsy-detected disease, suggesting a need to closely follow a patient’s PSA despite an initial negative biopsy.
The Worst Cancers Send Early PSA Signals that Would Allow Early Detection if Monitoring Focused on Increasing PSA (#1197): PSAV and its rate of increase over time may be a key marker in identifying aggressive disease and could provide valuable insight in how to interpret the PSA test, according to researchers from Medical University Innsbruck in Austria and the University of California, San Francisco. Study authors analyzed pre-diagnosis PSA history from 94 prostate cancer patients who, following surgical treatment, suffered extra-capsular extension (EE) or recurrence, and calculated annual growth rate in cancer PSA for each. Of the men with EE or recurrence, 98.9 percent had an increasing or constant PSAV and 95 percent had a PSA annual growth rate of 10 percent or more, suggesting that, in men with a current PSA less than 4.0 ng/ml, increased scrutiny of annual growth rates of 1.0 ng/ml or more may be warranted.
“Debate has been ongoing about the use of the PSA test in the detection of prostate cancer but the question may not be whether we use the test but, rather, how we use it,” said Christopher Amling, MD, who moderated the briefing for media. “These studies shed important light on how we might refine our use and interpretation of the PSA test.”
NOTE TO REPORTERS: Experts are available to discuss this study outside normal briefing times. To arrange an interview with an expert, please contact the AUA Communications Office at the number above or e-mail wisett@AUAnet.org.
About the American Urological Association: Founded in 1902 and headquartered near Baltimore, Maryland, the American Urological Association is the pre-eminent professional organization for urologists, with more than 17,000 members throughout the world. An educational nonprofit organization, the AUA pursues its mission of fostering the highest standards of urologic care by carrying out a wide variety of programs for members and their patients.
Wendy Waldsachs Isett, AUA