Men aged 55 to 69 should talk with their doctors about the possibility of taking a blood-based prostate cancer test. The test comes with many potential problems but brings the benefit of ever so slightly reducing the chance of dying from the cancer. That’s according to a new draft guidance out Tuesday from the US Preventive Services Task Force, an independent panel of experts appointed by the government to make evidence-based medical recommendations.

The new guidance is a bit of a walk-back from the USPSTF’s 2012 recommendation that all men take a hard pass on the blood screening, called a PSA test. Men 70 or older are still advised to skip. While the USPSTF doesn't address men younger than 55, that group is generally considered at low risk and not in need screening either. But, the new guidance opens the door to screening on a case-by-case basis for the 55 to 69 age group.

For that group, the task force writes in its draft guidance: “the USPSTF recommends individualized decision-making about screening for prostate cancer after discussion with a clinician, so that each man has an opportunity to understand the potential benefits and harms of screening and to incorporate his values and preferences into his decision.”

Those potential harms include over-diagnosis—getting a positive test result back that is later found to be false, causing stress and/or unnecessary treatments in between. There are also over-treatments, as well as complications that arise from normal treatments. For many men with prostate cancer, their disease will progress so slowly that they would not die from it if it were left untreated. However, doctors can’t tell the sluggish cancers from the killer ones. This spurs many men to opt for radiation and surgery right off the bat, which can cause urinary incontinence and impotence.

The upside, of course, is the potential to not die from cancer. The calculations to weigh those risks and benefits are tricky and inevitably controversial.

In crunching the latest numbers on the matter, the USPSTF came up with this statistical run-down:

Let’s say 1,000 men get a blood test for prostate cancer, which runs about $40 and measures the prostate-specific antigen (PSA), a protein made by the prostate gland. PSA levels become elevated in cases of cancer—but also benign prostate problems. Of the 1,000 getting a PSA test, 240 will get a positive result back (meaning their PSA levels appear elevated).

Of those 240, biopsies would find that only 100 have prostate cancer. The other 140 were false-positives.

Of the 100 with prostate cancer, 80 would typically choose surgery or radiation—either right away or after a period of “active surveillance” or mild treatment options. In those 80, at least 60 would have to suffer from the complications of urinary incontinence and/or impotence.

Of those 80, three men would be spared from having their cancer spread. And one or two would be kept from dying of prostate cancer over a 10- to 15-year period.

The new calculation of the one to two lives spared tipped the scales for the USPSTF to recommend that men 55 to 69 talk with their doctor and think about it.

“The balance of benefits and harms is still close,” Kirsten Bibbins-Domingo, an internist at the University of California at San Francisco and task force chair, told The Washington Post. “This is not a recommendation that says men should go get screened. This is a complex decision. Some men will want to avoid the chance of dying of prostate cancer no matter what, while others, given the side effects, will not think the benefits are worth it.”

The American Cancer Society and the American Urological Association are also on board with the "informed" or "shared" decision-making plan for screening.

The new guidance from the USPSTF is just a draft. The task force is taking public comments on it until May 8.

Editor's Note: The post has been updated to clarify the age groups that USPSTF examined.