The prostate-specific antigen test, commonly known as the PSA test, is valuable in predicting which men should have biopsies and which are likely to be diagnosed with low-risk prostate cancer, a Mayo Clinic study has found. The findings were released today during a meeting of the North Central Section of the American Urological Association in Rancho Mirage, Calif.
"The decision to use the PSA test is best made by the patient, in consultation with his doctor," says R. Jeffrey Karnes, M.D., a Mayo Clinic urologist and co-author of the paper, "Baseline PSA in Men Ages 40 - 60 Predicts Risk of Subsequent and Low-Risk Prostate Cancer in a Patient Cohort."
"One outstanding question has been the PSA test's value as a predictor of the need for a biopsy and future development of low-risk cancer,'' Dr. Karnes says. "Our study found a clear link between the test and these next steps in the prostate cancer continuum of care."
Since 1990, more than 600 men between ages 40 and 79 have been followed prospectively for prostate outcomes. The study found that men in their 40s with a baseline PSA at or above the median PSA were much more likely to undergo a biopsy and be diagnosed with low-risk prostate cancer; a similar trend was found for men in their 50s. However, the majority of tumors (89 percent) found in both age groups were classified as "low risk."
A PSA test is a common way for physicians to determine a patient's potential risk of developing prostate cancer. The test measures the amount of PSA, a protein produced by cells of the prostate gland, in the patient's blood.
Elevated PSA levels may result from a number of factors, including benign prostate enlargement or inflammation of the urinary tract, which is why additional tests are used in conjunction with the PSA test. For example, if the patient's physician suspects cancer, a biopsy of prostate cells likely will be ordered to confirm the diagnosis.
The PSA test is not without controversy: Recent draft recommendations from the U.S. Preventive Services Task Force suggest that the test may not save lives.
"As we continue to refine our approach to diagnosing and treating prostate cancer, we believe the findings of this study will help clinicians and their patients make informed decisions," Dr. Karnes says.