Wednesday, April 17, 2013
A study led by Memorial Sloan Kettering investigators indicates nearly half of all prostate cancer deaths by age 75 occur in a small group of men with high PSA levels at age 45.
Some doctors and researchers have recently questioned the benefits of prostate-specific antigen (PSA) blood testing for men, in light of the fact that it may detect slow-growing prostate cancers and result in unnecessary treatment and side effects. In fact, the US Preventive Services Task Force released recommendations in June 2012 stating that men should no longer undergo the test.
However, Memorial Sloan Kettering experts maintain that PSA testing saves lives, and have been working to determine smarter ways to screen men to ensure that those at a higher risk for aggressive prostate cancers can be diagnosed and treated, while those at a lower risk can avoid unnecessary treatment.
Now, a study published April 16 issue in the British Medical Journal reveals that certain men may need only three PSA tests in their lifetime.
“Our findings have led to recommendations that aim to ensure men get the maximum benefit from PSA screening,” explains statistician Andrew Vickers, who worked with a team of researchers at Memorial Sloan Kettering, the University of Washington, and Skåne University Hospital, in Sweden.
PSA Screening Recommendations
Investigators analyzed blood samples from a group of more than 21,000 men living in Malmö, Sweden, who participated in a large research study known as the Malmö Preventive Project. Though these men did not undergo regular PSA testing as part of their care, some were diagnosed and treated for prostate cancer.
Dr. Vickers and colleagues were able to test PSA levels in the blood stored from study participants and review the medical treatment records of these men to determine the aggressiveness of their cancers.
After analyzing this information, researchers concluded that most men should have their first PSA test around age 45, unless they have a strong family history of prostate cancer. Age 40 may be too early, and age 50 may be too late to identify a man’s risk of developing an aggressive cancer, Dr. Vickers explains.
This initial test can be used to place men on one of two screening paths:
- Men with a PSA level of 1.0 nanograms/milliliter or higher at age 45 are at an above average risk of developing life-threatening prostate cancer. These men should be regularly screened for changes in PSA level until around age 70, with repeat PSA testing.
- Men with a PSA level at or below 1.0 nanograms/milliliter should have two additional PSA tests, one in their early 50s and another at 60 to ensure that their PSA levels remain low. Testing is not necessary after age 60 because any cancer that develops will likely be slow growing and not life threatening.
“The big take-home message is that a single PSA test at age 45 can be used to predict a man’s long-term risk of developing an aggressive prostate cancer,” Dr. Vickers says.