2 March 2011
Prostate screening guidelines in need of revamp
by George Atkinson
Changes in PSA levels over time are a poor predictor of prostate cancer and may lead to many unnecessary biopsies, concludes a new study by researchers at Memorial Sloan-Kettering Cancer Center.
Writing about the study in the Journal of the National Cancer Institute, research leader Andrew Vickers said that he found no evidence to support the [current] recommendation that men with a high PSA velocity [changes in PSA levels] should be biopsied. "If a man's PSA has risen rapidly in recent years, there is no cause for concern if his total PSA level is still low and his clinical exam is normal," Vickers stressed.
Currently, the prostate cancer detection guidelines of several organizations (the National Cancer Center Network and the American Urological Association) recommend that men with a rapid rise in PSA (or a high PSA velocity) have a surgical biopsy for prostate cancer, even if there are no other indicators that cancer may exist.
Subjects in the study - more than 5,000 of them - came from the Prostate Cancer Prevention Trial. The men were followed with yearly PSA tests, with biopsy recommended for men with a PSA higher than 4.0 ng/mL. After seven years, all men who were not diagnosed with prostate cancer were asked to consent to an end-of-study biopsy. Vickers found no important association between PSA velocity and biopsy outcome after adjusting for risk factors such as age, race, and PSA levels.
"This study should change practice. We have previously published papers determining that PSA naturally varies from month to month and have urged men whose PSA suddenly rises to wait six weeks and repeat the test before agreeing to a needle biopsy. This new study in a large population of men provides even stronger evidence that using changes in PSA as a basis for recommendation for biopsy leads to many more unnecessary biopsies and does not help to find the more aggressive cancers," concluded co-researcher Peter T. Scardino.
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Source: Memorial Sloan-Kettering Cancer Center