Performing Repeat PSA Test Can Avoid Many Unnecessary Biopsies

October 13th, 2016

OTTAWA, CANADA – For decades, prostate-specific antigen (PSA) tests were routinely performed to help screen for prostate cancer.

Now, confusion and conflicting guidelines have left physicians unsure of when a PSA is appropriate and, if one is performed, how to follow-up without ordering an unnecessary biopsy.

A new Canadian study, published in Mayo Clinic Proceedings, offers some possible solutions. Researchers from The Ottawa Hospital and the University of Ottawa report that simply repeating abnormal PSA tests dramatically reduces unnecessary procedures.

It is the first to examine how promptly repeating PSA testing in a broad range of men being screened for prostate cancer can improve results and treatment.

"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 co-author Rodney Breau, MD. "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."

For the study, the research team reviewed the medical records of 1,268 men who had an abnormal PSA test results and were evaluated at the Ottawa Regional Cancer Assessment Centre between 2008 and 2013.

In a fourth of cases, the second PSA test came back normal. In fact, according to the results, only 28% percent 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.

The follow-up tests also increased accuracy, with diagnosis of cancer in only 3% of men with conflicting test results who had a biopsy, compared to 19% percent of men who had two abnormal tests.

"It is clear to me that any man with an abnormal PSA test should have this test repeated before a decision to biopsy," Breau said. "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."