New healthcare guidelines from Canada advise men against common blood tests to screen for prostate cancer, since according to the Canadian Task Force on Preventive Health Care, the negatives aspects after prostate-specific antigen (PSA) testing outweigh the positives.

“The ratio seems to be on the harm side – not the benefit side,” Dr. Neil Bell, a member of the Task Force and chair of its prostate cancer screening working group said in a Reuters press release.

In line with Canada, the U.S. Preventive Services Task Force does not recommend PSA screening for prostate cancer, along with the American College of Physicians, which does not advice men younger than 50 years and older than 69 years to undergo PSA screening. Furthermore, this institution believes men who are between these two age groups should be advised about the limited potential, benefits and possible harms of PSA screening before they consider taking the test.

“The most typical feeling most people have is, ‘If I diagnose cancer early and I treat it, I get a better outcome,’” Dr. Bell said in the press release. “For prostate cancer, that doesn’t hold for a number of reasons.”

These new guidelines, titled “Recommendations on screening for prostate cancer with the prostate-specific antigen test” were published in the Canadian Medical Association Journal (CMAJ), and show that about 70% of men between 70 and 79 years of age are diagnosed with prostate cancer after their death. This is in part due to the fact that the majority of prostate cancers will not cause men to die or feel sick, and as such early symptoms are not easy to detect.

“Available evidence does not conclusively show that PSA screening will reduce prostate cancer mortality, but it clearly shows an increased risk of harm,” the authors write in their study. “The task force recommends that the PSA test should not be used to screen for prostate cancer.”

However, Dr. Murray Krahn from the University of Toronto discusses in an accompanying commentary that men should have the choice of doing a PSA test. “There clearly is not enough evidence to mount an organized screening program,” he writes. “However, the falling overall mortality in some countries that screen intensively, the evidence that treatment may have a very modest disease-specific mortality benefit, and the highly variable preferences for treatment outcomes suggest to me that we should not push patients out of decision-making in this area.”