Sheldon Marks, MD
Sheldon Marks, MD, urologist and microsurgical specialist and clinical assistant professor of urology at the University of Arizona College of Medicine, Tucson, Arizona.
An influential government panel recently advised healthy men not to undergo routine screening for prostate cancer. The report has triggered protests from urologists—the doctors who diagnose and treat prostate cancer—who say that the test is very important.
We talked with urologist Sheldon Marks, MD, a noted expert on prostate cancer, about the panel’s findings and who should get the prostate-specific antigen (PSA) test…
In October of this year, the United States Preventive Services Task Force concluded that routine PSA screening does not save lives. This conclusion was based on five major clinical studies. The two largest, conducted in the US and Europe, found that the death rates of men who got the test were virtually the same as those who didn’t.
The panel also concluded that the PSA test leads to more tests and treatments that needlessly cause pain, impotence and incontinence in many men because most of the cancers that are detected are very slow-growing and unlikely to ever pose a threat.
What many patients and even doctors don’t understand is that the PSA test is not a specific test for cancer. It’s a very sensitive test that can detect abnormalities, but it’s not designed to identify a particular problem.
It is like an engine warning light in your car. When it flashes, you can’t tell if a particular spark plug is bad. It tells you only that something needs to be investigated.
About two-thirds of men with an elevated PSA don’t have cancer. They could have an inflamed or infected prostate (prostatitis). They could have a prostate gland that’s larger than normal (benign prostatic hyperplasia, or BPH). Also, PSA levels normally increase with age.
There even could be a laboratory error. A doctor should never encourage men to undergo invasive tests or treatments because of a single PSA reading. The test only alerts the doctor to the possibility of disease—and that disease might not be cancer.
Many doctors consider the normal range for PSA to be between zero and 2.5 nanograms per milliliter (ng/mL) of blood. Cancer cells release about 10 times more PSA into the blood than normal prostate cells. This is why an elevated reading is worrisome. But an elevated PSA, taken in isolation, doesn’t mean very much. Next steps…
Repeat the test in six to eight weeks. Laboratory errors are more common than people realize. A man with an unusually high PSA should have a second test to see if the numbers stay the same.
Even if the first test was accurate, the numbers could be transitory. A high PSA often will return to normal when an underlying condition—infection or inflammation, for example—clears up. I’ve seen men with a PSA reading as high as 100 that wasn’t caused by a cancer.
Repeat the test once or twice a year. If a man tests high on his initial PSA test and it’s confirmed with follow-up testing, he may be given the option to get retested in three to six months to a year. If the numbers have dropped, as they often do, nothing more needs to be done. If the PSA still is high, there might be an underlying problem—and cancer is one possibility.
Watch for an increase. A progressive increase of PSA over time, known as velocity, is more worrisome than a single high reading. The larger the jump, the higher the risk for cancer.
Schedule a biopsy. This is the logical next step when a man’s PSA continues to rise. The prostate gland is numbed with a local anesthetic. A spring-loaded device extracts a dozen hair-size slivers of tissue from the part of the gland that’s most likely to contain cancer cells. The samples then are analyzed in a lab.
Biopsies aren’t perfect. They can miss the part of the prostate that contains cancer cells. There also can be uncertainty about the results.
If cancer is present, the pathologist will give it a Gleason score, a measure of the cancer’s aggressiveness. Though we have a good idea, it’s still not possible to predict with total accuracy how dangerous the cancer is likely to be.
Helpful: The PCA3 urine test. This usually is performed when a man has a negative biopsy but continues to have a high PSA. The PCA3, which identifies genetic markers associated with cancer, can help determine if a man needs a second biopsy.
The task-force recommendations apply only to healthy men. A man with symptoms, such as difficult or painful urination or blood in the urine, must see a doctor and get tested.
I also strongly recommend PSA testing starting at ages 40 to 45 for men with a family history of prostate cancer. They’re far more likely to get cancer than men without this history. All African-American men should get tested at ages 40 to 45—they have a higher risk for prostate cancer than Caucasian men.
Men in their mid-70s or older often don’t need the PSA test. Even if they develop a cancer—or have harbored cancer cells in the prostate for decades—it’s unlikely that the cancer will grow fast enough to cause problems during their expected life span. Virtually all men, if they live long enough, eventually will have cancer cells in the prostate gland. The majority of these cancers are indolent—they grow so slowly that they are unlikely to ever cause disease.
Of course, Americans are living longer than ever, and plenty of 80-year-olds are healthy and active. An older man who thinks that he has a decade (or more) ahead of him should ask his doctor about testing.
The fact that the PSA test is not perfect does not mean that we should return to the old days of no testing. More than 33,000 American men die each year of prostate cancer. But today, with earlier detection from PSA testing and treatment, about 95% of patients survive for at least 10 years—and many are cured.
The task-force report is a general public-health recommendation that does not agree with those of many prostate cancer experts. The task-force recommendation doesn’t exclude men from getting the test—and insurance companies probably will continue to pay for it. Every man should ask his doctor if, or when, he should get tested.
The bottom line is that the PSA remains a valuable and sensitive test that, when interpreted correctly, saves lives and prolongs life span for men with prostate cancer.