12 Things Men Must Know About PSA Tests
What is a PSA test?
Prostate-specific antigen (PSA) is a protein produced by the prostate and found in the blood.
A PSA blood test can detect prostate cancer early, but it may not save lives. Sound confusing? It is. Many prostate cancers grow slowly, so a PSA test may save the lives of some men while causing others to have unnecessary surgeries or radiation treatments, which could cause lifelong problems such as erectile dysfunction or incontinence.
Here's what you need to know about PSA tests before having one.
Low PSA is good
But so many factors influence PSA that a single test is never enough to diagnose prostate cancer. If you do have high levels of PSA, your doctor may suggest a prostate biopsy or another test to determine if you have cancer.
False positives are possible
If your PSA is elevated, your doctor may first address other issues, such as treating an infection, and then test you again to see if the levels go down.
Other risk factors are important
If, however, your prostate-cancer risk is lowif, for example, you have no risk factors and a digital rectal exam reveals no abnormal-feeling areas in your prostateyour doctor may decide to forego a biopsy and instead do another PSA test a few months or so down the road.
Most biopsies don't show cancer
Approximately three out of four men who have biopsies after positive PSA tests are cancer-free, according to one large study.
"The downside of getting a biopsy is there's about a 3% chance of having a bad infection from it, and it's anxiety producing," says Tracey Krupski, MD, a urologic oncologist and assistant professor of urology at the University of Virginia, in Charlottesville.
Experts don't agree on when to start
Draft guidelines from the U.S. Preventive Services Task Force say men shouldn't get a PSA test unless they have prostate-cancer symptoms.
That may be too late, says James Mohler, MD, a professor of oncology at the Roswell Park Cancer Institute, in Buffalo, N.Y.
"We'd love to have a better test than PSA," says Dr. Krupski. "We're working on it."
Testing has a psychological impact
"There's definitely a negative psychological effect," says Richard Hoffman, MD, a professor of medicine at the University of New Mexico School of Medicine, in Albuquerque.
PSA tests may not save lives
One life would be saved for every 1,400 men tested over a nine-year period, according to the study. Another recent study of men in the United States, however, found annual PSA tests didn't decrease the risk of dying from prostate cancer.
But the tests may nevertheless be worthwhile. "Since we've been doing PSA testing in America, we've had the largest drop in mortality from prostate cancer of any country," Dr. Krupski says.
Healthy men over 75 can skip the test
"Everyone who gets to age 75 with a normal exam and a normal PSA absolutely should stop," he adds. Older men are likely to outlive any prostate cancer identified after that point, Dr. Mohler says. The ACS guidelines recommend PSA testing only in men who expect to live at least another 10 years.
Rate of rising PSA is important
For example, men who are undergoing "watchful waiting"the monitoring of low-risk prostate tumors before resorting to treatmentmay be candidates for treatment if their PSA rises more than 0.75 ng/mL each year.
There's decision-making help
But it's a complicated issue. For more guidance, you can check out the American Cancer Society's list of free decision aids on prostate-cancer screening. These are step-by-step guides to help you figure out whetherand howyou should get tested and treated for prostate cancer based on your own values and concerns.
Test or not? It's your decision
If you're not anxious about prostate cancer but you are concerned about the side effects of testing and treatment, for example, it may make sense for you to skip screening. On the other hand, if you know all these side effects and are concerned about prostate-cancer risk, you should get screened.
You can avoid unnecessary treatment
"This simple blood test enters them into this cascade of downstream events that leads to a lot of uncertainties and trade-offs between benefits and harms," Dr. Hoffman says. "Not just the biopsy, but also the diagnosis and treatment, because if you don't consider that you could be unpleasantly surprised down the road."