Men with high PSA test results as early as age 45 are three times more likely to develop a life-threatening form of prostate cancer than those with lower levels, according to a new study that provides fresh evidence that the controversial screening method can benefit younger men.
Despite new federal guidelines issued last year that recommend against routine PSA testing for men at any age, an international team of U.S. and Swedish researchers found the risk of being diagnosed with an aggressive prostate cancer that spreads to other parts of the body and bone within 15 years is three-fold higher for men aged 45-49 with elevated PSA levels than those with lower concentrations.
What’s more, the risk of developing metastatic prostate cancer is 10 times greater for men aged 51-55 with high PSA test results. Taken together, the findings — published in the British Medical Journal — suggest nearly half of all deaths from prostate cancer can be predicted before age 50. What's more, initiating PSA screening after then may leave many men at risk of being diagnosed with an incurable form of cancer, the researchers found.
“Measurement of PSA concentration in early midlife can identify a small group of men at increased risk of prostate cancer metastasis several decades later,” the researchers concluded. “Careful surveillance is warranted in these men.”
David Samadi, M.D., vice chairman of the Department of Urology and Chief of Robotics and Minimally Invasive Surgery at the Mount Sinai School of Medicine in New York City, tells Newsmax Health the findings provide a strong endorsement of PSA testing. That’s particularly true for men in their 40s who have an increased cancer risk because of their family history, genetics, race, and other factors.
“We know the PSA test has reduced the mortality of cancer by 40 percent, so it has been an effective test,” said Dr. Samadi.“Of course we need a better test. But 10, 15 years ago we used to see people coming in with metastatic [cancer], where had spread to other parts of the body and spread to the bone, but we don’t see that that much anymore.”
PSA (prostate-specific antigen) is a protein produced by cells of the prostate gland. PSA is often elevated in men with cancer, and the test was originally approved by the U.S. Food and Drug Administration in 1986 to track the progression of cancer in men diagnosed with it. In 1994, the FDA approved the use of the PSA test with a digital rectal exam (DRE) to test asymptomatic men for prostate cancer.
But an elevated PSA does not necessarily indicate the presence of prostate cancer. It can also flag other non-cancerous conditions, such as prostatitis (inflammation of the prostate) and benign prostatic hyperplasia (enlargement of the prostate).
Most doctors consider PSA levels of 4.0 nanograms of PSA per mililiter (ng/mL) of blood and lower to be normal. Those with PSAs of 4.0 or higher are often sent for a prostate biopsy to check for cancer.
Until recently, many doctors and health organizations encouraged yearly PSA screening for most men beginning at age 50. But recent studies have shown that some men with PSA levels below 4.0 have prostate cancer, while many men with higher levels do not have prostate cancer.
Last year, the United States Preventive Services Task Force —an independent panel of experts authorized by Congress — issued new recommendations against routine PSA screening, regardless of age, for men without cancer symptoms.
But the new study raises questions about those guidelines. For the study, researchers examined medical data from the long-running Malmo Preventative Project to determine who might benefit most from PSA testing — and at what age. A previous study using MPP data, published in the BMJ in 2010, demonstrated that PSA level at age 60 can predict the risk of death from prostate cancer by age 85.
The Malmo study included 21,277 men, aged 27 to 52, who participated in the MPP between 1974 and 1984. All gave blood samples to be tested for PSA levels. The results showed 44 percent of deaths among the men from prostate cancer occurred in those with the top 10 percent of PSA levels at age 45-49 — a PSA of 1.5 ng/ml or more.
In fact, the risk of developing metastatic prostate cancer within 15 years was three times higher for men in the top level PSA at age 45-49 and 10 times higher at age 51-55. This suggests that initiating PSA screening after age 50 would leave many men at risk of later being diagnosed with an incurable cancer. But even men with the highest PSA levels at age 40 had a very low risk of developing metastatic prostate cancer within 15 years, indicating PSA testing is not justified at that age for most men.
Dr. Samadi noted the study finds PSA testing is beneficial, but must be conducted and analyzed by a doctor who specializes in its use and that it be done over a period of time to track patterns and trends.
“There’s an art to managing the PSA test and it should be handled by doctors who use the PSA all the time,” he said. “I don’t just look at the value alone, but I look at the trend over time.”
He recommends men start the PSA screening at 45, as a baseline, then get a PSA once a year afterward. Some men at increased risk for cancer should start PSA screening at 40 — including African-Americans, those with a family history of the disease, and men with variations in the genes BRCA1 and BRCA2 (tied to both prostate breast cancer).
“Medicine is really like detective work,” Dr. Samadi explains. “You have to use the art to decide who should have the PSA test and who should not. You have to look at the [results of] a physical exam, the race, family history, then the genetic package … and then decide who should be screened.”
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