If you’re a man over 50, you’ve likely thought about or taken a PSA, or prostate-specific antigen test, a blood test that is used to screen for prostate cancer.
The risk of developing this cancer—the most common form of cancer discovered in men and the second highest cause of cancer-related death in men—rises with age. Most prostate cancers are diagnosed in men age 65 to 69.
But even though deaths from prostate cancer have dropped since the PSA test came on the scene—from 31.6 per 100,000 in population in 1999 to 18.9 in 2015—it’s still one of the most controversial medical tests that aging men regularly receive.
The problem with the PSA
The prostate-specific antigen is a protein produced by normal as well as malignant cells. Your PSA can rise due to an enlarged prostate, a benign condition that often occurs as men age, or due to an infection that causes prostatitis. You could also have a so-called indolent cancer that is not likely to ever cause death. Men often live to very old age with these cancer cells in their prostates and don’t die from prostate cancer.
Despite this lack of clarity, a high or rising PSA often leads doctors to recommend that men get a prostate biopsy. During a biopsy, 10 to 12 needles are inserted into the prostate through the rectum, to determine whether or not there actually is any cancer and if so, whether it is of the aggressive type.
Biopsies can have a number of side-effects, including bleeding, infection and erectile dysfunction.
These side effects of biopsy led the U.S. Preventive Services Task Force to issue a recommendation against getting PSA exams, because the benefits to a small population were outweighed by the risks to the larger population of elderly men without aggressive cancers. The task force has since moderated its advice, and now urges patients to consult with their doctors about getting regular PSA exams.
A new test shows promise
Now there is a new generation of PSA testing available, which many primary doctors are still unaware of, that can alleviate many of the concerns that arose from the original test. It doesn’t replace the PSA, but adds another level of screening that doctors can use to make a much more informed decision about follow-up measures.
The proprietary test, known as the OPKO 4K score, measures four different PSA proteins in the blood. A similar test offered by a different company is known as Prostate Health Index.
Instead of testing just for total PSA, the 4K measures four biomarkers, and then puts the results in an algorithm that includes age, previous biopsies and digital rectal exam results to produce a percent risk for the presence of cancer.
According to a number of recent research studies, that gives doctors a much more accurate picture of who is likely to have cancer.
“The 4k does a better a job of distinguishing PSA rises due to BPH (benign prostate enlargement) versus PSA rises that could indicate cancer,” says Dr. Eric Klein, chair of the Glickman Urological and Kidney Institute at the Cleveland Clinic.
Perhaps more importantly, the test helps urologists distinguish between aggressive cancers and indolent cancers before making a decision on whether to conduct a biopsy, says Sanoj Punnen, an assistant professor of urology at the University of Miami Miller School of Medicine, who was the lead author in a 2015 research study that validated the use of the 4K test.
For example, a 4K score of less than 7.5% means that the risk of developing metastatic prostate cancer within 20 years is less than 2%. Those men can skip getting a biopsy even though their PSA might be above 3, the usual cutoff for recommending a more thorough physical exam.
“Most of the guys who have elevated PSAs don’t have a aggressive cancer,” Punnen says. “Having a test more specific for cancer, ideally a significant cancer, is the best way moving forward.”
Weighing your options
Chances are, if you have a high or rising PSA, your primary care doctor will suggest further testing. Unless there are warning signs of a very serious condition, such as an initial PSA above 20, you can ask your physician or urologist for a referral to a lab that provides the 4K before having the prostate biopsy performed.
The 4K is available only at special blood testing labs, not through such usual blood labs as Quest or Labcorp. It’s covered by Medicare and other insurance plans: If you have to pay out of pocket, it costs about $300 to 400. But that may seem like a reasonable cost given the worry and discomfort it can save.