U.S. Prostate Cancer Incidence Falls after Change in Screening Recommendations
U.S. Prostate Cancer Incidence Falls after Change in Screening RecommendationsSoon after an independent task force recommended against routine screening of men aged 75 and older for prostate cancer with the prostate-specific antigen (PSA) test, the incidence of early-stage prostate tumors in that population declined, a new analysis shows. The findings suggest that the revised recommendations led to a reduction in prostate cancer screening rates in older men.
The U.S. Preventive Services Task Force (USPSTF) conducted a systematic review of the medical literature and issued the recommendations in August 2008.
"There's a lot of skepticism that these types of recommendations will have an impact on practice patterns, but at least in this case it looks like there has been some [impact]," said study author Dr. David Howard of Emory University in an interview posted online.
For his analysis, published July 23 in Archives of Internal Medicine, Dr. Howard used data from more than 254,000 men with prostate cancer from NCI's Surveillance, Epidemiology, and End Results registry.
He hypothesized that if screening rates in men aged 75 and older fell, the incidence of early-stage prostate tumors, which are detected primarily by PSA-based screening, would also fall relative to the incidence of late-stage tumors and of early-stage tumors in younger men. "And that's exactly what I found," he said in the online interview.
Between 2007 and 2009, the incidence rate for early- and late-stage prostate tumors fell 25.4 percent and 14.3 percent, respectively, among men aged 75 and older. By contrast, the incidence rate for early-stage tumors dropped 15.2 percent among men aged 65 to 74, and 11 percent among men aged 30 to 64, over the same period.
Dr. Howard's conclusions differ from those of an earlier report that found that self-reported PSA screening rates in men aged 75 and older did not change between 2005 and 2010. Several factors may explain the discrepancy. For instance, "patients do not [always] accurately report receipt of PSA testing," he explained via e-mail, noting that physicians who stopped screening older men may not have discussed this decision with their patients.
Over time, a clearer picture should emerge of physicians' responses to revised screening recommendations.
"Dr. Howard's data are interesting and relevant," commented Dr. Scott Eggener of the University of Chicago, senior author of the earlier study. "As with all self-reported or population-based data, it's important to replicate using multiple sources."
In a study that is still under review for publication, Dr. Howard also examined PSA testing rates directly using Medicare claims, which he noted are more reliable than patient self reports. He expects the findings from that study to be published soon.
Further reading: "U.S. Preventive Services Task Force Advises against PSA Screening"