Should men get prostate cancer test?
BY DR. CHRISTOPHER LILLIS
For Father’s Day, I want to provide our male readers with a personal revelation. By now, you probably have heard about the United States Preventive Services Task Force recommendation against routine prostate cancer screening using the prostate specific antigen (PSA) blood test.
But you may wonder what your doctor is going to do for himself and his family. Personally, I do not plan to allow my physician to screen me for prostate cancer using the PSA blood test.
I would caution all men to carefully weigh the risks of the test. Though you may know someone whose prostate cancer was caught by the test, the odds are that the test will do you more harm than good.
WEIGHING THE ODDS
If you’re confused about what to do, it’s not surprising. In preparing this column, I watched a video produced by a national network news organization that hosted a televised debate between the chief medical officer of the American Cancer Society and a basketball coach who happened to have been treated for prostate cancer.
What ensued was a reasoned scientific analysis from a world-renowned physician making a point about apples, and a survivor of prostate cancer making an emotional argument about oranges. I imagined that I would be very confused after that “news” piece had I not had a medical education, training in statistics, and years of experience caring for my patients.
The coach, however, was right in one regard. The PSA screening test does save lives. In screening all men for prostate cancer using the PSA test, we save about one life for every 1,000 men who get a PSA test.
Of those 1,000 men who are screened using the PSA blood test, seven will die of prostate cancer instead of the eight who would die if no PSA screening occurred.
The problem? For those same 1,000 men who get a PSA test, 180 will get an unnecessary prostate biopsy that will show no cancer, and another 20 men will have a slow-growing prostate cancer found and treated in some fashion—even though the cancer never would have harmed their health.
For those men who have a biopsy, they carry a small risk of bleeding after a biopsy, of impotence, incontinence and even a life-threatening infection. For men who get treated, the risks of incontinence and/or impotence climb dramatically.
These risks are small, but they need to be considered when so few men have their lives saved by this mass screening strategy. The odds of not having cancer are so much greater than having cancer, let alone a cancer that will cause your death.
The questions about screening focus on the larger population, not just individuals. Is it worth it to save one life (per 1,000 screened) and still have 200 “harmed” by unnecessary treatment or biopsy? Is it worth it to risk impotence or incontinence from a biopsy when the odds are stacked in your favor that you do not have cancer?
If you’re diagnosed with prostate cancer, should you undergo treatment if you are much more likely to live unharmed with a slow growing cancer than have prostate cancer shorten your lifespan?
These are difficult questions to wrestle with, because human psychology cares not for statistics. “Cancer” is a very bad word, and we have been indoctrinated to do everything we can to prevent it.
But not all cancers are alike. Some cancers are aggressive and spread rapidly through the body, dramatically shortening our life span, while others are indolent and may never cause us harm.
Prostate cancers are much more likely to be harmless than to spread, although sorting out which is most likely to occur in an individual patient is almost impossible with our current medical tools.
If so few men have their lives saved by being screened for prostate cancer with a PSA test, why should anyone have the test?
Men do die from prostate cancer: rough estimates put the number of deaths from prostate cancer at about 30,000 per year. This number is significant, but you are more likely to die in a car accident (40,000 deaths in the US per year) and much more likely to die of cardiovascular disease (600,000 deaths per year). Simply for comparison, about 40,000 women die of breast cancer each year and 160,000 people die of lung cancer—highlighting the much more aggressive nature of lung cancer.
I actually believe that the PSA test may come back into favor in the future, once we have better means to:
- Distinguish between which elevated PSA is associated with cancer and which stems from more common causes, such as benign prostate enlargement and infections.
- Distinguish between slow-growing harmless prostate cancers and fatal ones. We can’t do that now, but this will come with developing technologies using DNA analysis and molecular markers that are currently being studied.
Once we can decide if a biopsy or treatment is absolutely needed, PSA may yet again become a mass screening strategy, because we will be able to prevent the harms from over-screening.
This is the challenge of being a physician or an educated patient in 2012. We need to adapt this population-based recommendation against the personal care of an individual patient.
WHO’S LIKELY TO BENEFIT
So who should consider getting a PSA test?
If you have had a family member who died of prostate cancer, you have a much greater chance of benefiting from PSA screening rather than being harmed.
If you have symptoms of prostate problems, a careful strategy of cancer screening with or without the PSA blood test may be warranted.
If you have had a PSA test already, and you wish to continue screening, paying close attention to how that PSA level changes from year to year is a much more predictive strategy than a single value. When a PSA level rises rapidly, it is much more likely to indicate cancer than a single elevated value.
I would advise all the men reading this column to carefully consider their personal risk of dying from prostate cancer vs. the risk of being harmed by screening. Discuss this risk with your physician.
The PSA blood test is here to stay, but it should be used with greater mindfulness and caution. Simply getting a PSA test because you are a man should fall by the wayside, but screening for prostate cancer if you are at a higher risk should continue with more care.
So no PSA testing for me—I like my odds.
Dr. Christopher Lillis, of Chancellor Internal Medicine, can be reached at healthyliving@freelance star.com.
Get more insight into prostate cancer screening here:
Chart showing effects of screening: commonhealth.wbur.org/2012/05/prostate-screening-chart
An essay on the effects of overdiagnosis: theincidentale conomist.com/wordpress/more-diagnoses-are-not-always-a-good-thing