The prostate-specific antigen (PSA) test is the most controversial health issue facing men today. Many consider it crucial for early detection and treatment of prostate cancer, noting that in the years after it was approved, the number of prostate cancer deaths dropped by 40%.
The catch-22: Even though some experts believe that PSA testing has played a key role in reducing the number of deaths from prostate cancer, it can’t differentiate harmless cancers (the majority) from aggressive ones. Studies have shown that men whose levels test high are only marginally less likely to die from prostate cancer, on average, than those who were never tested…and they’re more likely to have biopsies, surgeries and other risky treatments that will make no difference in their long-term health.
That’s why a 2012 task force advised against widespread screening. Within a year, PSA testing had dropped by 28%—but there was a corresponding decline in the diagnoses of potentially risky cancers.
To sort through the issues, Bottom Line Health spoke with H. Ballentine Carter, MD, an internationally recognized expert in the diagnosis and treatment of prostate cancer.
Isn’t early cancer detection always a good thing? Not for prostate cancer. Most tumors discovered by routine PSA tests are indolent—slow-growing cancers that pose no risk to a man’s long-term health. The tests do find some dangerous cancers, but not many. Over a 10-year period, only one life will be saved for every 1,000 men who are screened.
It’s tempting to argue that saving the lives of a few men (particularly if you’re one of them) outweighs the inconvenience for the thousands who aren’t helped. But the test isn’t merely a bother for those who test positive. Many of these men will be subjected to biopsies and other treatments, including surgery—and possible complications such as incontinence and impotence—for cancers that never would have been a threat.
Do you agree with the guidelines for curtailed testing? It’s worth pointing out that no government agency has ever recommended mass PSA screening. It’s an important test for select men, but it’s not for everyone—and it needs to be used more judiciously.
Consider an 80-year-old man who is expected to live for another five or 10 years. Does he need to have a PSA test? Probably not, because most prostate cancers are slow-growing. He’s unlikely to die from prostate cancer, even if cancer cells are already present.
But a man in his 50s should consider having the test every two years. If his PSA is low—for example, between 0 ng/ml and 2.5 ng/ml—he can rest easy. If his level is high—10 ng/ml or above—he can work with his doctor to decide if he needs a biopsy or other tests/treatments.
Won’t reduced screening cause more cancer deaths? In the year after the 2012 task force recommended against routine PSA testing, the number of prostate cancer diagnoses dropped. Much of the reduction involved low-risk cancers, but there was also a reduction in the diagnoses of higher-risk cancers, according to a study published in The Journal of Urology. This is potentially worrisome, although it’s unclear whether the “missed” diagnoses will eventually lead to more cancer deaths. The goal for now is smarter testing, not more testing.
What do you mean by “smarter”? The PSA test can’t distinguish meaningless tumors from lethal cancers. Yet some doctors urge men to undergo biopsies based on a single high reading. That’s a mistake.
If a man’s PSA is, say, 10 ng/ml, that’s concerning. But what if the high reading is transitory and caused by something other than cancer? What if the lab made an error?
Even when a high PSA is caused by cancer, a single high reading might not mean it’s a lethal cancer. I worry more about PSA velocity—the amount that PSA increases over time and how quickly it rises. A continuously rising PSA—especially more than one point per year—can point to an aggressive cancer.
What if my PSA tests high? Don’t panic. All sorts of things besides cancer can cause a high PSA reading—infection, inflammation and even ejaculation within the past 48 hours can cause a temporary increase. Your doctor should recommend a repeat test within a few weeks or months, possibly followed by annual or semiannual testing. Do not agree to a biopsy unless your doctor is convinced that cancer is a strong possibility.
Also helpful: A new test approved by the FDA in 2012, the prostate health index (PHI), looks at different types of prostate cancer-specific biomarkers—total PSA, free PSA and pro-PSA. The score from the combined factors is more reliable than PSA alone. Research has shown that this type of testing—along with even newer tests, such as the 4Kscore, that look for other cancer “markers”—can reduce unnecessary biopsies by about 30%.
What’s the “sweet spot” between too much testing and not enough? When the task force guidelines were issued, PSA tests were overused. Also, only about 10% of men who were tested and diagnosed with prostate cancer were managed with active surveillance. This approach doesn’t rush men into treatment—they undergo monitoring that may include digital rectal exams and biopsies. The goal is to determine more precisely which men will truly benefit from treatment.
Active surveillance is now used in up to 40% of patients. This is good and might encourage more testing because men will be reassured that they’ll be treated only for cancers that pose a real threat.
What advice do you have for men who want to be tested? A healthy man, without a family history of prostate cancer (in his father, brother or son), should consider having a PSA test between the ages of 50 and 55 and then every two years but only after a conversation with his doctor about potential risks and benefits. Men with a family history of prostate cancer and African-American men—both of whom are at increased risk—should ask their doctors about earlier testing.
A man needs to ask himself if he can deal with the stress if his PSA is high, suggesting that he might have cancer. Can he live with the idea that he might have a “harmless” cancer? Or will he insist on a biopsy that might lead to unnecessary surgery or other treatments? That’s exactly what we’re trying to avoid.
