It's official: The PSA blood test to screen for prostate cancer has been downgraded to the lowest possible rating of "D" from the U.S. Preventive Services Task Force, an influential independent advisory board that basically decides what types of preventive care are worth the bother. That's "D" as in "discourage," which is what the task force says doctors should do when their patients ask about this test.
If reaction to the committee's preliminary "D" grade last fall is any indication, this downgrade is likely to set off howls of outrage from various quarters and indignation from the many men who are convinced that the screening test saved their lives.
The thing is, it probably didn't, the task force concluded. It helpfully supplied some numbers to back this up, based on two large recent clinical trials in the U.S. and Europe. Without PSA screening, about five of 1,000 men older than 50 will die of prostate cancer within 10 years. With screening, 110 of those men will be diagnosed with prostate cancer, of whom four to five will die of the disease in the same period. Or, to put it another way, between zero and one person will avoid death from prostate cancer in a decade for every 1,000 people that get the test.
Based on that number alone, a $22 blood test might seem a small price to pay for peace of mind.
But consider that an unknown but probably very high percentage of cancers thus diagnosed and treated would probably have never caused any symptoms, because most prostate cancers are so indolent that their "victims" die of something else first.
"We tend to have an oversimplified sense that once cancer is anywhere, it could be everywhere, and it's deadly," says John Santa, M.D., director of the Consumer Reports Health Rating Center. That's not true of many cases of prostate cancer, but sadly there's not yet a reliable way of distinguishing a common lackadaisical case from the rarer aggressive one that really is out to kill you.
Set against that are the downsides of treating a cancer that, as we've just seen, is likely not to be fatal. Ninety percent of men diagnosed with prostate cancer opt for some kind of treatment, most commonly surgery or radiation, to get rid of it. And those treatments have nasty side effects. Of every 1,000 men who get screened (which, remember, prevents between zero and one deaths from prostate cancer):
• two will develop serious cardiovascular events.
• two will experience a life-threatening blood clot in a leg vein or lung.
• 29 will end up with erectile dysfunction.
• 19 will become incontinent.
Where does this leave the millions of men who have been getting their PSA checked for years? Back in the doctor's office, having a "conversation" about risks and benefits.
"It's not like the task force is saying the test is illegal," Santa points out. "They're saying it's not a good screening test and trying to get people to make sure they know what they're getting into."
A good way to have the conversation is to challenge your doctor if he continues to prescribe routine PSA screening, says Helen Darling, president and CEO of the National Business Group on Health. "If the doctor says, 'Oh, everybody has it, don't worry,' then you need to change doctors. Because if they don't talk about the harm, then they're not giving you full information."
Read more about other unnecessary tests and treatments.
Screening for Prostate Cancer: U.S. Preventive Services Task Force Recommendation Statement [Annals of Internal Medicine]