Researchers at Memorial Sloan-Kettering Cancer Center have found that change in PSA levels over time, known as PSA velocity, does not predict of prostate cancer and may lead to many unnecessary biopsies.
Several groups, including the National Cancer Center Network and the American Urological Association, recommend that men with high PSA velocity get a biopsy for prostate cancer, even if there are no other indicators that cancer may exist.
"We have found no evidence to support the recommendation that men with a high PSA velocity should be biopsied in the absence of other indications. Those indicators could be an elevated baseline PSA or a positive digital rectal exam (DRE)," said Andrew Vickers, Associate Attending Research Methodologist in the Department of Epidemiology and Biostatistics and lead author.
The researchers studied 5,519 men aged over 55, who were participating in the prostate cancer prevention trial, with no previous prostate cancer diagnosis, normal DRE, and a baseline PSA of 3.0 ng/mL or less.
The study subkects were randomly assigned to finasteride, a drug commonly used to treat enlargement of the prostate gland, or placebo for seven years.
The team focused on men in the placebo group who were followed with yearly PSA tests. After seven years, all men in the study underwent a biopsy.
Based on these tests, the team found no important link between PSA velocity and biopsy outcome, noting that PSA alone was a much better predictor of biopsy outcome than PSA velocity.
"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," said Peter T. Scardino, Chair of the Department of Surgery.
"This study 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 that we want to find and treat," he added.
The study is published online in the Journal of the National Cancer Institute.