The task force acknowledged that "some men will continue to request screening," but said doctors "should not offer or order" it unless they first "engage in shared decision-making that enables an informed choice by the patients."
Urologists and advocacy groups immediately decried the advice - as they did when a draft version was released last October - and worried that insurers may stop paying for PSA testing.
But other experts applauded the unflinching recommendation, pointing out that screening dilemmas have already led the medical community to turn away from automatic PSA testing. Even the American Urological Association recommends that testing be "individualized" and that men be informed about the risks of over-detection and overtreatment.
The association nonetheless on Monday condemned the blanket rejection of screening as "inappropriate and irresponsible."
One of the most vocal critics of routine testing - Richard J. Ablin, 72, who discovered the prostate-specific antigen in 1970 - was jubilant. For decades, he has said that using the blood protein to try to flag cancer in the reproductive gland is "hardly more effective than a coin toss." He says the test should be reserved for monitoring prostate cancer patients for recurrence after treatment.
"I'm thrilled that I lived to see this," said Ablin, an immunobiologist at the University of Arizona College of Medicine. "For 38 years I was called a wacko" for saying the PSA test was being misused.
Prostate cancer is now diagnosed in one out of every six men - double the rate before screening became standard in the early 1990s.
The rationale behind early detection is that a nascent tumor is easier to treat and cure than advanced disease. But prostate cancer complicates this reassuring notion.
It is more common in the old, with the average age at diagnosis of 67. Many malignancies grow so slowly that they never cause symptoms - namely, urinary problems, blood in the urine, or pain. On autopsy, many elderly men are found to have undetected prostate cancer, studies show.
The PSA test cannot distinguish these slow-growing tumors from deadly ones, or even tell malignant from benign conditions. The amount of PSA in the blood tends to rise with prostate enlargement or infection as well as with cancer.
What's more, a "normal" PSA level does not rule out cancer. Experts continue to debate where to set the cutoff, and how much to rely on abrupt changes in PSA levels rather than absolute numbers.
In recommending against PSA-based screening, the task force reviewed many studies, but relied heavily on two major clinical trials, one in the United States and the other in Europe.
The U.S. trial followed 76,685 men for at least 13 years. Although the prostate cancer incidence was slightly higher in men who were screened compared with men who were not, their death rates were no different.
In the European trial, which followed 162,243 men for a median of 11 years, the screened group had a markedly higher incidence of cancer - 8.2 percent - and a 21 percent reduction in prostate cancer deaths, or about 1 fewer death per 1,000 men screened.
Avoiding that death involved a lot of complications, the panel found.
For every 1,000 men, at least 100 are sent for a biopsy that does not find cancer - with a third suffering biopsy-related pain, bleeding, or infection, not to mention anxiety.
And 110 more men undergo a biopsy that does reveal cancer, and 99 of them go on to have surgery, radiation or testosterone-deprivation therapy.
Treatment will cause one of them to develop a life-threatening blood clot, two to have heart attacks, and up to 40 to lose control of their sexual or urinary function. Bowel dysfunction is also a side effect of radiation therapy.
In an editorial in the journal, leading prostate cancer specialists criticized the task force for not including any urologists or oncologists, for overlooking flaws in the trials, and for ignoring the harms that come with delayed diagnosis.
Since the early 1990s, the proportion of men who have metastatic disease (cancer in distant organs) at the time of diagnosis has fallen from 70 percent to 3 percent.
"When I started my career, men usually presented with bone metastases," said Northwestern University urologist William Catalona, lead author of the editorial. "They died a horrible death. In the old days, prostate cancer used to be like pancreatic cancer. We feel they're throwing away the baby with the bath water."
Critics also said high-risk men - African Americans and those with family histories of prostate cancer - deserve special consideration. Instead, the task force simply said there isn't enough data to know whether the balance of risks and benefits are more favorable for them.
One African American who agrees with the task force is Otis Brawley, the American Cancer Society's chief medical officer. If anything, he said, the harms of overdiagnosis and overtreatment are greater for blacks. They are more vulnerable to treatment complications because they start out with more chronic illness such as diabetes and heart disease.
"I have never been screened," said Brawley, a professor of oncology and epidemiology at Emory University. "Ever since the mid-1990s, I have been outspoken in saying the science to show this is beneficial is just not there."
Fallout from the task force report is sure to go on for months or years.
Lorraine A. Ryan, a spokeswoman for the Centers for Medicare and Medicaid Services, said the new recommendation "does not require a change in private health coverage of prostate cancer screenings or treatment, and prostate cancer will remain a covered benefit under Medicare at this time."
Even so, advocates are expected to enlist politicians in defending screening. After the October release of the task force's draft report, the urologists association said it "engaged its champions in Congress" to send protest letters to Health and Human Services Secretary Kathleen Sebelius. The New Jersey Legislature and the Pennsylvania House Health Committee also called on Congress to reject the recommendation.
"These urologists who are screaming and yelling, this is taking money out of their pockets," said Ablin, who discovered PSA. He estimates screening costs at $3 billion a year, much of it paid for by Medicare and the Veterans Administration.
Meanwhile, the American Academy of Family Physicians has already updated its guidelines, coming out against PSA screening, to conform to the task force position. Other groups are expected to follow suit.
The growing consensus that screening is not a public health boon should help doctors grappling with the controversy, said Dan Merenstein, a family physician at Georgetown University.
In 1999, while he was a medical resident in Fairfax, Va., Merenstein discussed the risks and benefits of PSA screening with patients, just as he had been trained to do. One 53-year-old man who opted not to have the test reappeared four years later - with a lawsuit.
The man had inoperable prostate cancer and argued that the Fairfax medical practice was just trying to save money by using "shared decision-making." Jurors exonerated Merenstein but found the practice liable for $1 million.
"Shared decision-making is very very difficult. It's tough for patients to understand why they might have a cancer but not want get it out," Merenstein said. "I think this [task force recommendation] will help doctors. Now, it would be hard for lawyers to argue it's a good test."
The PSA controversy, he added, has obscured the obvious: "We all want a good screening test. This just isn't it."
Contact Marie McCullough at 215-854-2720 or firstname.lastname@example.org.