Repeating Abnormal PSA Tests Reduces Number of Unnecessary Biopsies
For more than 20 years, the prostate-specific antigen (PSA) test has been used to help screen for prostate cancer. However, in recent years, some task forces have called for this blood test to be abandoned because it leads to many unnecessary biopsies. Now, a new study from The Ottawa Hospital and the University of Ottawa showed that simply repeating abnormal PSA tests can dramatically reduce unnecessary biopsies.
The study is the first to examine the impact of prompt repeat PSA testing in a broad range of men being screened for prostate cancer. It was published by Lavallée et al in Mayo Clinic Proceedings.
“A high PSA level is associated with a greater risk of prostate cancer, and PSA screening can help detect cancer at an earlier, more treatable stage,” explained Rodney Breau, MD, FRCSC, a prostate cancer surgeon and Associate Scientist in Epidemiology at The Ottawa Hospital and the University of Ottawa.
“However, PSA levels can also fluctuate because of infections, physical activity, and laboratory error. Because of this variation, we implemented a protocol to always repeat an abnormal test before referring a patient for a biopsy. We had a hunch that this would reduce unnecessary biopsies and our study shows that our suspicion was correct,” he said.
Study Findings
The research team reviewed the medical records of 1,268 men who had an abnormal (high) PSA test result and were evaluated at the Ottawa Regional Cancer Assessment Centre between 2008 and 2013. In 25% of these men, the second PSA test came back normal. Only 28% of men with conflicting test results underwent a biopsy compared to 62% of men who had two abnormal test results, representing a 55% reduction in biopsies.
In addition, only 3% of men with conflicting test results who had a biopsy were diagnosed with cancer within the year, compared to 19% of men who had two abnormal tests, suggesting that the second normal test is important.
“It is clear to me that any man with an abnormal PSA test should have this test repeated before a decision to biopsy,” concluded Dr. Breau. “Some doctors and patients may be worried about missing a significant cancer diagnosis if they forgo a biopsy after conflicting test results, but our study shows this is very unlikely. It is also important to remember that the PSA test is just one factor we evaluate when deciding to do a biopsy, and these decisions are always made together with the patient, and can be revisited if risk factors change.”
“Our study has important implications for patients,” said Luke Lavallée, MDCM, a prostate cancer surgeon and researcher at The Ottawa Hospital and the University of Ottawa. “Prostate biopsies can be uncomfortable and inconvenient for patients, and in rare cases, they can lead to infections, so we only want to do these if they are really necessary.”
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
