No major medical group recommends routine PSA blood tests to check men for prostate cancer, and now a U.S. government panel is saying they do more harm than good and healthy men should no longer receive the tests as part of routine cancer screening.

The panel's guidelines had long advised men over 75 to forgo the tests and the new recommendation extends that do-not-screen advice to healthy men of all ages. 

The recommendation by the U.S. Preventive Services Task Force, being made public on Friday, will not come as a surprise to cancer specialists.

Yet, most men over 50 have had at least one PSA blood test, the assumption being that finding cancer early is always a good thing.

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Competitors raise funds for prostate and other cancers that occur below the waist. Routine PSA screening for prostate cancer is in dispute. ((Darryl Dyck/Canadian Press))

Not so, said Dr. Virginia Moyer of the Baylor College of Medicine, who heads the task force.

"We have put a huge amount of time, effort and energy into PSA screening and that time, effort and energy, that passion, should be going into finding a better test instead of using a test that doesn't work," Moyer told The Associated Press late Thursday.

Too much PSA, or prostate-specific antigen, in the blood only sometimes signals prostate cancer is brewing. It also can mean a benign enlarged prostate or an infection. Worse, screening often detects small tumours that will prove too slow-growing to be deadly.

And there's no sure way to tell in advance who needs aggressive therapy.

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The Canadian approach involves doing a PSA test and biopsy but not overtreating prostate cancer, said Dr. Neil Fleshner. (CBC)

The task force analyzed all the previous research on this subject, including five major studies, to evaluate whether routine screening reduces deaths from prostate cancer. The conclusion: There's little if any mortality benefit.

But there is harm from routine screening: impotence, incontinence, infections, even death that can come from the biopsies, surgery and radiation, Moyer said.

Balanced information needed, cancer society says

One study estimated two of every five men whose prostate cancer was caught through a PSA test had tumours too slow-growing to ever be a threat.

Yet, Moyer said, 30 per cent of men who are treated for PSA-discovered prostate cancer suffer significant side-effects, sometimes death, from the resulting treatment. 

About a third of men ages 40 to 60 have brewing prostate cancer but "the huge majority of them will never know it in their lifetime if they are not screened," she added.

The task force previously had considered the evidence for or against PSA screening inconclusive. The new recommendation says not to routinely screen. That recommendation is a draft that is open for public comment beginning next week.

"We have been long concerned, and it has been 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," said Dr. Otis Brawley of the American Cancer Society in a statement. "We need balanced, truthful information to be made widely available to physicians and patients when making important health decisions."

Varied opinions in Canada

The society had not seen the new recommendation yet, but has long advised men to consider the pros and cons of PSA screening before deciding on their own.

Moyer said the recommendation only means that doctors shouldn't bring up the option for healthy men. If a man asks for a PSA test and wants it after being informed of the evidence, he should receive it, she said. Likewise, it's appropriate to use PSA tests to examine a man with possible prostate symptoms.

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PSA screening often detects small tumours that will prove too slow-growing to be deadly. (CBC)

In Canada, there are varied opinions on PSA testing among patient and health-care professionals.

"Our Canadian approach â€¦has been to yes, do the PSA test, yes do the biopsy of those men because we want to help those who are destined to die early from the disease by finding it early, but not overtreating those men who exhibit features that suggest they don't need to be treated," said Dr. Neil Fleshner, a urologist at the University Health Network and Princess Margaret Hospital in Toronto.

The Canadian Cancer Society's website said research does not clearly show if the benefits of testing for prostate cancer outweigh the harms.

"We recommend that you talk to your doctor about your risk for prostate cancer and about the benefits and harms of early detection," the society said.

Prostate Cancer Canada said men should talk to their doctors starting at age 40 to establish a baseline PSA and then a screening schedule depending on risk level.

The Canadian Task Force on Preventive Health Care, the counterpart to the U.S. Preventive Services Task Force, last reported in 1994. At that time, it found insufficient evidence to support the need for PSA screening.

With files from CBC's Kelly Crowe