Rates of prostate cancer screening and early-stage prostate cancer diagnoses are down, especially in men ages 75 and older, according to a new study from the American Cancer Society. Researchers attribute the decline, in part, to the 2008 and 2012 U.S. Preventive Services Task Force (USPSTF) recommendations against routine prostate cancer screening.
“I’m happy that screening is down – if the reason is because men have been able to make informed decisions about whether to be screened. Evidence of harm from prostate cancer screening is stronger than evidence of benefit,” says Otis Brawley, MD, chief medical officer at the American Cancer Society. “Though there is some data to suggest that it saves lives, we had been curing a lot of people that didn’t need to be cured, who were never going to die from prostate cancer.”
Brawley, a co-author of the study that was recently published in JAMA, adds that whether the drop in screening and detection is good news won’t be known for years, when there is enough data to examine mortality rates.
The Case Against Routine PSA Screening
Prostate cancer screening was once routinely recommended as part of regular checkups for men older than 50. That meant an average-risk man with no signs of prostate trouble would get a blood test looking for elevated levels of PSA, or prostate-specific antigen, a marker for possible prostate cancer. If cancer was found, treatment often followed.
The problem is that treatment, which is often not necessary, can reduce quality of life: Incontinence and impotence are two common side effects. That’s why in 2008 the USPSTF recommended against routine prostate cancer screening for men ages 75 and older – and why the panel expanded their recommendation in 2012 to include average-risk men of all ages.
Society researchers set out to examine prostate cancer trends in the wake of these recommendations against routine PSA-based screening.
“Previous research showed that prostate cancer incidence rates in men 75 years and older substantially decreased following the 2008 recommendation. Our study extended this analysis by examining changes in incidence rates and PSA screening after the 2012 recommendation against screening for all men,” says lead author Ahmedin Jemal, DVM, PhD, vice president of the surveillance and health services research program at the American Cancer Society.
Jemal, Brawley and colleagues examined newly diagnosed prostate cancer cases using 18 national Surveillance, Epidemiology, and End Results (SEER) registries. They also looked at PSA screening “in the past year” among men ages 50 and older who responded to the 2005, 2008, 2010 and 2013 National Health Interview Survey (NHIS).
From the SEER data, it was clear that rates of early-stage prostate cancer diagnoses began decreasing with the first USPSTF recommendation. In 2008, there were 540.8 new cases diagnosed per 100,000 men ages 50 and up. In 2012, the year with the most recent available data, there were 416.2 new cases per 100,000 men ages 50 and up.
From the NHIS data, researchers found that in 2013, 31% of men ages 50 and older said they’d had a PSA test in the past year. That’s down from 2010, when the number was 38%, and from 2008, when it was nearly 41%.
Making Sense of the Numbers
This study contributes to the evidence that the 2008 recommendation led to a significant drop in prostate cancer screening and incidence among those 75 and older. But what could account for similar declines among men ages 50-74 before the USPSTF recommendation applied to them?
“The decrease may be due to changes in perception of the importance of PSA screening among providers and the general public following the 2008 recommendation,” Jemal says.
Another possible reason, he adds, is an increased emphasis on informed decision making over the past several years – something the American Cancer Society has long advocated. Society guidelines for prostate cancer detection state that men in certain age groups should get screened only after they have weighed the possible risks and possible benefits with their health care providers.