Study: PSA Testing Cuts Worst Prostate Cancers
Threefold Fewer Metastatic Prostate Cancers Since Routine PSA Testing
PSA Screening Controversy
The U.S. Preventive Services Task Force recently recommended against routine PSA screening.
"At best, PSA screening may help one man in 1,000 avoid death from prostate cancer after 10 to 14 years," task force co-chair Michael LeFevre, MD, MSPH, of the University of Missouri, writes in an email to WebMD. "We now know that the PSA test harms many more men in the course of testing and treatment after a positive result."
But what about Messing's study?
"This study is not a randomized trial, and the results don't tell us much about whether screening reduces a man's chances of having metastatic prostate cancer," LeFevre notes. "Since death from prostate cancer will nearly always be preceded by metastatic disease, one would expect a significant decline in metastatic disease to be accompanied by a significant reduction in deaths. But that is not what the clinical trials show."
Messing agrees that his study is not a screening study, although he argues that the European trial of PSA screening did indeed show the same reduction in metastatic cancer as his study predicted. And this reduction, he says, argues strongly in favor of routine PSA tests for all men starting at age 50 and older, and for higher risk men starting in their 40s.
Kramer says Messing is right when he says screening itself doesn't save lives. Only treatment can do that. And the evidence unfortunately shows that prostate cancer treatment isn't as good as everyone would like it to be.
A recent study in the New England Journal of Medicine looked at men whose early-stage prostate cancer was detected by PSA tests. Those treated with radical prostatectomy -- considered the most effective if not the safest treatment -- were only about 3% more likely to be alive 10 years later than those not treated.
And PSA testing carries risks. According to LeFevre:
- Men with suspicious PSA scores get biopsied, but up to 80% of these biopsies find no cancer.
- Once a biopsy finds cancer, there's no way to tell for sure if it's going to kill him. Nine out of 10 U.S. men opt for treatment.
- For every 1,000 men who get treatment after PSA screening, one gets a blood clot, two have a heart attack or stroke, and up to 40 become incontinent or have urinary incontinence.
- One in 1,000 men who gets PSA screening will avoid dying of prostate cancer, but one in 3,000 will die as a result of surgery.
PSA: Should Men Get the Test?
So should men get regular PSA tests?
Many urologists, who often treat men suffering terribly from late-stage prostate cancer, agree with Messing that they should. But many experts on screening tests, who often see doctors fail to accept medical evidence that conflicts with their experience, agree with LeFevre that they should not.
The American Cancer Society has this advice: Men should only get the PSA test after having a detailed talk with a doctor about the benefits and risks of PSA screening.