Some doctors welcomed the change by the influential panel of experts, saying it would save many men from experiencing false alarms and potentially serious complications of unnecessary treatment.
Others feared the new recommendation would cause more men to die from prostate cancer because their tumors would not be found until the cancer had progressed.
But no one knew what would happen.
Two studies released Tuesday don't settle the issue, but they do shed light on the effect of the recommendation against screening: Both studies found a sharp drop in PSA testing, and one found a significant fall in the rate at which men are getting diagnosed with prostate cancer.
"The take-home message to me is that the American public actually did listen to the U.S. Preventive Services Task Force," says Dr. Otis Brawley, the chief medical officer at the American Cancer Society, which conducted one of the studies.
For years, doctors recommended that middle-age and older men routinely get the PSA test. The test is named after a protein called prostate-specific antigen, which prostate tumors produce. The level of the protein in the blood can indicate the presence of a tumor. It can also be high for other reasons, including a urinary tract infection.
But the task force concluded the testing caused unnecessary suffering and that there was insufficient evidence that annual PSA screening significantly reduced the death rate from prostate cancer. That's because many men get biopsies, surgery and radiation for tumors that never become life-threatening, the task force concluded. The treatment often leaves men impotent and incontinent. In rare cases, treatment can cause fatal complications.
In the latest research, published in JAMA, the Journal of the American Medical Association, the cancer society analyzed data from government registries and surveys that track cancer diagnoses and screening. The analysis found the percentage of men ages 50 and older who reported PSA screening in the previous year fell by 18 percent — from 38 percent of those men in 2010 to 31 percent in 2013.
The researchers also found the rate at which men were diagnosed with prostate cancer fell from 505 per 100,000 in 2010 to 416 in 2012. That means 33,519 fewer men were being diagnosed with prostate cancer each year, the researchers calculated.
A second team of researchers at the Brigham and Women's Hospital in Boston and the Henry Ford Health System in Detroit conducted a separate analysis that was published in the same issue of JAMA. That analysis found PSA screening dropped 16 percent — from 36 percent of men to 30 percent — during the same period.
The decline in screening is "very disturbing," says Vanderbilt University urologist David Penson, who wrote an editorial accompanying the papers. Penson fears that the drop in screening and diagnosis will lead to an increase in deaths from prostate cancer.
In 2015, more than 220,000 men are expected to be diagnosed with prostate cancer and more than 27,000 to die from it, according to the American Cancer Society. Prostate cancer is the most common cancer among men.
"Prostate cancer screening is certainly not perfect. But it doesn't mean we should throw the baby out with the bathwater," Penson says. "If your loved one died because there was no screening, that makes a big difference to you."
But others welcome the trend, saying it will save many men from unnecessary suffering.
It's been clear for many years that there's a "much greater chance that a PSA test would lead to preventable misery such as impotence or incontinence, compared to any chance of having one's life saved," says Dr. Howard Brody, a professor of medical humanities at the University of Texas Medical Branch in Galveston, wrote in an email.
Many experts say one key question is how the decision to screen or not screen is being made.
"I think it's a good thing if doctors and men are having a discussion so that the patient can truly make an informed decision," says the American Cancer Society's Brawley. "I think its a bad thing if the doctors are making a decision and not discussing it with the patient at all."
Doctors on both sides of the debate also agree it will take more time before anyone knows how the drop in screening and diagnoses will affect one obviously important outcome of this debate: What happens to the death rate from prostate cancer?
"I think for the most part the jury is still out," says Dr. Howard Parnes, a specialist in prostate cancer prevention at the National Cancer Institute who wasn't involved in the new research.