With several years now passing since the USPSTF issued its grade D recommendation discouraging PSA-based prostate cancer screening, researchers are reporting conflicting findings on its impact on clinical practice.
Chicago-With several years now passing since the U.S. Preventive Services Task Force (USPSTF) issued its grade D recommendation discouraging PSA-based prostate cancer screening, researchers are reporting conflicting findings on its impact on clinical practice.
While a handful of studies show a significant decline in screening since the recommendation was released in 2012, two abstracts presented at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago arrived at essentially opposite conclusions. One paper, using insurance claims data, showed no significant change in screening in men who are most likely benefit from it. The second, based on self-reported data, found screening rates significantly declined in all subgroups of men, but to a lesser extent in men over age 75 years.
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“I realize that the two abstracts use two different databases, but they found diametrically opposed findings on the effects of the USPSTF recommendation in older men,” said J. Brantley Thrasher, MD, professor and chair of urology at the University of Kansas Medical Center, Kansas City, and a Urology Times editorial consultant.
A number of studies presented at the AUA annual meeting in New Orleans and a recently published paper in the Journal of Urology suggest prostate cancer screening is trending downward (see, “New data show shifts in PSA screening”).
At the ASCO meeting, a study conducted by researchers at Case Western Reserve University in Cleveland analyzed private health insurance claims data (Optum Labs Data Warehouse) from 2008 to 2013 for men ages 40 to 80 years. It identified 11.6 million men who met eligibility criteria for inclusion in the study, of whom 2.9 million (25%) underwent PSA screening. Men ages 50-59 years represented the plurality (~43%), while just over 20% of the men were 40-49 years of age and just under 20% were in the 60-64 year age bracket.
The analyses showed PSA screening rates fluctuated monthly throughout the study period.
However, between 2008 and 2013, there was no significant change in the rate of men undergoing PSA screening for the overall population (190.4/1,000 member-years vs. 196.4/1,000 member-years) or when stratifying men by age (40-49, 50-59, 60-64, 65-69, 70-74, and 75-80 years), except in the oldest cohort.
Dr. KimAmong men ages 75-80 years, the PSA screening rate was almost 50% lower in 2013 than in 2008 (124.1/1,000 member-years vs. 201.5/1,000 member-years), although the decline really occurred by 2010, and the PSA screening rate was stable thereafter.
“By showing no appreciable drop in PSA screening for men who should be considered for screening, meaning those 55 to 69, but a significant drop in the advanced age group, our findings could be considered good news that we are not screening older men who are unlikely to benefit,” said Simon P. Kim, MD, MPH, assistant professor of urology at Case Western Reserve University School of Medicine.
In contrast, investigators using self-reported data on PSA screening from men ages 40 years and older who participated in the 2010 and 2013 National Health Interview Survey found screening significantly declined from 2010 to 2013 among all subgroups of men ages 50 years and older. The study was presented at the ASCO annual meeting and published online in theJournal of Clinical Oncology (June 8, 2015).
First author Michael W. Drazer, MD, noted the findings are consistent with those emerging from studies based on more limited populations, including one using data from a regional health system in Chicago.
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Most striking to Dr. Drazer and colleagues, however, was their finding that the absolute declines in PSA-based screening were bigger in the 50-59 and 60-74-year subgroups (33.2% to 24.8% and 51.2% to 43.6%, respectively) than in men ages 75 years and older (43.9% to 37.1%). In addition, they were disappointed by the fact that in 2013, more than one-third of men ≥75 years of age and nearly the same proportion of men age >65 years with a high predicted risk of 9-year mortality (defined as >52% calculated with an externally validated index) had PSA screening.
“Work from researchers at the University of California, San Francisco showed that the USPSTF recommendations have the strongest influence on PSA screening ordered by primary care physicians [Prostate Cancer Prostatic Dis 2012; 15:189-94], and our findings are consistent with that information,” said Dr. Drazer, an internal medicine resident at the University of Chicago Medical Center, Chicago.
“Unfortunately, our findings are the opposite of what we hoped to see, which is that men who are less likely to benefit from early detection of prostate cancer because they are advanced in age and less healthy would be screened less often than younger, healthier men. In our study, 1.4 million men at high risk of dying with prostate cancer but not from it underwent PSA screening in 2013,” said Dr. Drazer, who worked on the study with Scott Eggener, MD, and Dezheng Huo, MD, PhD.
In a study published in 2012 that used the same methodology, Dr. Drazer and colleagues found no evidence that the 2008 USPSTF recommendations affected prostate cancer screening rates (JAMA 2012; 307:1692-4).
Dr. Drazer said that their studies have limitations associated with use of patient self-reported data. However, he noted that patient recall of PSA screening has been shown to be reasonably reliable, and responses from survey participants on PSA screening were only included in the analysis if the man first correctly answered a question asking if he knew what a PSA test was.
On the other hand, Dr. Drazer mentioned there is evidence that physicians don’t discuss PSA screening with patients in a way that would support the accuracy of self-reported information.
“A man’s knowledge of his PSA screening probably depends on his having the right discussion with his physician. However, we recently published research showing that a lot of men are not having this conversation,” he said, citing a study appearing in Cancer (2014; 120:1491-8).
“Overall, it seems there needs to be a lot of improvement in patient and physician education on PSA screening.”
Discussing the strengths and limitations of the Case Western research, Dr. Kim told Urology Times that the study is novel because it provides a look at PSA screening 1 year after the 2012 USPSTF recommendations in a nationwide population of privately insured men, including a large sample of “younger” men who are most likely to benefit from screening. However, he acknowledged it is subject to the limitations of using insurance claims data. Furthermore, the analysis is based on a single private payer’s database and it cannot be assumed that its findings reflect screening rates for men in other insurance plans.
“It will be important to look again in a few years using more contemporary data and to investigate this question in other patient populations,” Dr. Kim said.
A recently published paper and studies presented at the 2015 AUA annual meeting suggest the rate of prostate cancer screening is falling.
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