Despite the fact that a major U.S. panel has recommended against prostate-specific antigen blood testing for prostate cancer in older men, a new study shows that many continue to get the testing. The findings, researchers say, cast doubt on the direct impact of previous recommendations.
"When these guidelines come out, they certainly make a lot of waves and get a lot of coverage," said Dr. Scott Eggener, assistant professor of surgery and urology at the University of Chicago Medical Center and one of the authors of the study, published Tuesday in the Journal of the American Medical Association.
"This really calls into question the impact and downstream effect," he continued.
Relying on data from the 2005 and 2010 National Health Interview Surveys, Eggener and his co-authors studied how patient practice was influenced by 2008 guidelines from The U.S. Preventive Services Task Force that recommended against PSA screening in men 75 and older.
They found virtually no change: 43 percent of men aged 75 and older underwent screening in 2005, versus 43.9 percent in 2010.
In an interview, Eggener stressed that the aim of the new study was not to weigh in on the merits of the 2008 recommendation, which concluded that there is "moderate certainty that among those men, the harms of screening outweigh the benefits."
Nor was the goal of the new research to answer why there seems to be such a disconnect between the panel's recommendation and widespread practice. However, the authors did hypothesize that "lack of guideline awareness, financial incentives or patient or physician confidence in PSA screening" may all play a role.
"Early detection is something that we in the U.S. have gravitated toward over the last 75 years," said Dr. Otis Webb Brawley, who is chief medical officer of the American Cancer Society and was not involved in the study. "There is an inherent prejudice that it is always a good thing. It usually, it frequently is, but 'always' is too strong a word."
Different groups get different recommendations when it comes to screening, Brawley said. The American Cancer Society recommends that starting at age 50, men have a conversation with their doctors about the pros and cons of getting tested for prostate cancer. The disease is currently the most common cancer among men in the U.S., and more than 64 percent of all cases are diagnosed in men over 65.
To better understand how guidelines in general may change clinical practice, the authors call for the continued monitoring of patterns, particularly after the draft 2011 recommendations from the U.S. Preventive Services Task Force that were issued last fall. Those guidelines, which have been a subject of debate, recommend against routine testing for prostate cancer regardless of age.
And experts say that while the impact of panel guidelines on PSA screening may be negligible at present, that could change in the coming years.
"Just as it took a while to promote screening in the U.S.," said Dr. Christopher Logothetis, chair of the Department of Genitourinary Medical Oncology at the MD Anderson Cancer Center, "it will take a while to refine the use of screening."