Early Prostate Cancer Cases Fall Along With Screening

Fewer men are being screened for prostate cancer, and fewer early-stage cases are being detected, according to two studies published Tuesday in The Journal of the American Medical Association.

The number of cases has dropped not because the disease is becoming less common but because there is less effort to find it, the researchers said.

The declines in both screening and incidence “could have significant public health implications,” the authors of one of the studies wrote, but they added that it was too soon to tell whether the changes would affect death rates from the disease.

Because prostate cancer often grows slowly, the panel said, screening finds many tumors that might never have harmed the patient. But they are treated anyway. As a result, it concluded, testing saves few lives and leads too many men into unneeded surgery or radiation, which often leaves them impotent and incontinent.

An editorial accompanying the articles, by Dr. David F. Penson, the chairman of urologic surgery at Vanderbilt University Medical Center, acknowledged that too much screening could do harm but suggested that the pendulum had swung too far the other way.

Rather than issuing a blanket recommendation against screening, Dr. Penson said, it would be better to “screen smarter” by testing most men less often and focusing more on those at high risk.

One of the new studies, by researchers from the American Cancer Society, found that early-stage diagnoses of prostate cancer per 100,000 men age 50 and older dropped to 416.2 in 2012, from 540.8 cases in 2008, with the biggest decrease occurring from 2011 to 2012 - after a draft of the task force guidelines was released in October 2011. The authors estimated that the total number of diagnoses decreased to 180,043 in 2012 from 213,562 in 2011 - a difference of 33,519 cases.

That difference may indicate that many men were spared needless treatment - exactly what the task force had hoped to accomplish with its guidelines. But the authors also said, “Less screening or discontinuing screening may lead to missed opportunities for detecting biologically important lesions at an early stage and preventing deaths from prostate cancer.”

The percentage of men 50 and older who reported PSA screening in the previous 12 months dropped to 30.8 percent in 2013, from 37.8 percent in 2010.

Although the study could not prove that the drop in screening caused the drop in diagnoses, the authors said it was the most plausible explanation.

The findings were based on data from cancer registries and national surveys that asked men about prostate screening.

A second study, by researchers from several medical centers, also found a significant decline in PSA testing after the 2012 task force recommendations.