When it comes to your health, can you be too cautious? That’s the persistent debate happening over a blood test used to screen for prostate cancer that some doctors say actually “overdiagnoses” the disease in men.
The controversy peaked again last week when the American Urological Association called for men 40 or older who are expected to live at least another decade to be offered prostate-specific antigen (PSA) testing. Previously, the AUA recommended the test for men 50 or older—which is in line with the Canadian and American cancer societies. The discrepancy highlights the confusion among health organizations and even patients about the pros and cons of PSA testing.
The screening is undeniably useful, says Dr. Neil E. Fleshner, head of urology at Princess Margaret Hospital in Toronto. “It will take men who are destined to die from prostate cancer and save their lives,” he says. “Make no doubt about it.”
The problem is that PSA testing may also lead to unnecessary anxiety and suffering. That’s because high levels of PSA can be caused by a number of medical conditions other than cancer. “It could mean an enlarged prostate, infection or inflammation,” explains Dr. Brant Thrasher, chairman of urology at the University of Kansas, and spokesperson for the AUA. “So it’s not a perfect marker.”
PSA is a naturally occurring protein made in the prostate, which scientists believe cuts the viscosity of semen so that sperm can swim easily to fertilize an egg. As a man ages, his PSA level may rise. Thrasher says that while the risk of prostate cancer is low in young men, by testing PSA at age 40, physicians will have a baseline from which to compare future levels and more easily detect potential problems.
If a PSA test shows elevated levels of the protein, then a man will need a biopsy to figure out why. The procedure—an 18-gauge needle through the rectum and into the prostate—can severely stress men out, says Fleshner. (As invasive as this sounds, Thrasher says his patients often liken the pain to the flick of a rubber band.) What’s more, critics argue that if the results don’t reveal cancer, then the man and his family may have worried needlessly. And some aggressive types of prostate cancer can’t be detected using PSA because they don’t cause the protein level to spike, explains Thrasher.
When prostate cancer is found, continues Flesher, treating it with surgery or radiation can sometimes lead to urinary or sexual side effects, such as erectile dysfunction. In a patient whose prostate cancer is lethal, this may be a minor trade-off, says Fleshner. But some prostate cancer is so so slow to progress and non-threatening that the treatment for it may be unjustifiably harsh. “Not every one who has prostate cancer is destined to die from it,” he says. “If we’re taking a number of men and giving them side effects and treatment and not really helping them, then that’s a problem.” In these cases, active surveillance of the patient rather than immediate treatment may be the best option, he says.
Despite the reality that PSA is an imperfect marker for detecting prostate cancer, both Thrasher and Fleshner believe the benefits of the test are profound. Fleshner, who personally thinks that men should receive PSA testing starting in their mid-40s, says that a number of provincial committees have been established recently to further investigate the best recommendations for prostate cancer screening.
At whatever age men get tested, adds Thrasher, “You can’t have PSA done in a vacuum. We need to know if there are other risk factors” such as family history or additional health issues. He and Fleshner urge men to talk to their doctor about their own risk about when they should begin screening. “The key is informed consent on behalf of the physician and patient,” says Fleshner, “rather than ‘let’s open a kiosk in the mall and start drawing PSA.’ ”