By Steven Reinberg
FRIDAY, Oct. 7 (HealthDay News) -- News that a key government advisory panel will give a thumbs-down next week to a controversial blood test for prostate cancer is garnering both praise and condemnation from experts.
A draft report due out early next week from the United States Preventive Services Task Force (USPSTF) will recommend that healthy men forego regular prostate-specific antigen (PSA) testing aimed at spotting prostate cancer, the The New York Times and other media outlets reported Friday.
The USPSTF is the same independent group of medical experts that caused a firestorm in late 2009 when they ruled against the use of annual mammographies for average-risk women in their 40s.
The PSA test has been similarly controversial, since its overall benefit in saving mens' lives has been challenged by a number of studies. Among the reasons the USPSTF cited in rejecting the PSA test is that the screen does not save lives and instead can result in unnecessary treatments that can leave men with discomfort, impotence and incontinence.
According to the Times, the task force focused on the results of five trials, the two largest done in Europe and in the United States. The European trial included 182,000 men. Over nine years of follow-up, it found no reduction in deaths due to prostate cancer among men of all ages in the study who were underwent PSA testing. But it did find some reduction in deaths among men aged 55 to 69 who got the blood test.
The American trial, involving almost 77,000 men followed for over a decade, also failed to show an overall reduction in deaths among all the men who were screened.
"Unfortunately, the evidence now shows that this test does not save men's lives," Dr. Virginia Moyer, a professor of pediatrics at Baylor College of Medicine and chairwoman of the task force, told the Times. "This test cannot tell the difference between cancers that will and will not affect a man during his natural lifetime. We need to find one that does."
But Dr. Anthony D'Amico, chief of radiation oncology at Brigham and Women's Hospital in Boston and a prostate cancer expert, said the task force's recommendation is misguided.
D'Amico noted that in the European study, screening reduced cancer deaths among these younger men by 44 percent. The U.S. study also showed a 44 percent reduction in cancer death among younger men, he added. "If they look at all the screening studies, they will find that the people who benefited most from screening were the youngest and presumably the healthiest," he noted.
"The panel has not really appreciated the entirety of the evidence," D'Amico said. "Considering all of the data, it appears that younger or healthier men benefit from PSA screening."
Right now, most men are advised to undergo regular PSA tests beginning at age 50. However, because most prostate cancers grow very slowly and may never prove fatal, the value of early treatment has come into question.
Of course, some prostate tumors are aggressive and can prove deadly. Most experts acknowledge that the real problem, right now, is that there's no reliable test to tell a patient which type of tumor he might have.
Dr. Otis W. Brawley, chief medical officer of the American Cancer Society, also cautioned that the task force's decision is not yet set in stone.
"It is important to keep in mind that under the new USPSTF process, the recommendation is not final until the conclusion of the public comment period and the USPSTFs review of those comments," he said.
According to Brawley, the cancer society pored over the existing body of evidence in 2009 and at that point it determined that it could not conclude whether or not PSA screening saves lives.
"We have long been concerned, and it has been very apparent for some years, that some supporters of prostate cancer screening have overstated, exaggerated and, in some cases, misled men about the evidence supporting its effectiveness," Brawley said. "We need balanced, truthful information to be made widely available to physicians and patients when making important health decisions. Sadly, that has not happened with this disease."