Prostate-specific antigen (PSA) screening rates declined between 2008 and 2019 at the U.S. Veterans Healthcare Administration (VHA), according to a study at the American Society for Radiation Oncology (ASTRO) 2022 annual meeting in San Antonio.
Researchers led by Dr. Alex Bryant from the University of Michigan also found in their study of nearly 5.5 million men that long-term nonscreening rates increased in the VHA system. Additionally, they found ties between lower facility-level PSA screening rates and higher subsequent rates of metastatic prostate cancer.
"These data can be used to inform shared decision-making about the potential benefits of PSA screening in men who wish to reduce their risk of prostate cancer metastases," Bryant and colleagues wrote.
The jury is out on whether PSA screening's benefits outweigh the potential harms. Advocates say such testing can help detect prostate cancer early. But detractors argue that although these tests detect cancer, often described as slow growing, it's tricky to determine whether these detected cancers would have caused symptoms or harm during a man's lifetime. They add that men who are overdiagnosed and overtreated carry emotional and physical burden.
PSA screening rates have declined since 2008. The researchers noted that this trend is led by changing practice guidelines and clinical trial results that conflict with one another when it comes to screening benefits. Previous research also shows that the incidence of metastatic prostate cancer has risen since then.
However, the study authors pointed out a lack of direct epidemiologic evidence that ties these two trends together. Bryant and colleagues wanted to add to the literature, analyzing data from a study population that included 4.7 million men in 2005 and increased to 5.4 million in 2019.
They used VHA data to calculate PSA screening rates, long-term non-screening rates where no PSA was measured in the prior three years, and age-adjusted metastatic prostate cancer incidence rates from 2005 to 2019.
| PSA screening, metastatic prostate cancer incidence rates between 2008 and 2019 | ||
| 2008 | 2019 | |
| PSA screening rate | 50.8% | 37% |
| Metastatic prostate cancer incidence rate (per 100,000) | 4.6 | 7.9 |
The researchers noted declines for PSA screening in all age and race groups. Also, the long-term nonscreening rate similarly increased in this period. The team added that metastatic prostate cancer incidence trends were driven by increases in age groups for men aged 55 to 69, as well as those 70 and over.
Among other findings, lower facility-level PSA screening rates were linked to higher subsequent cancer incidence. This includes a 0.87-unit increase in the 2014-2019 metastatic prostate cancer incidence rate per 10% decrease in the 2010-2013 PSA screening rate (p < 0.001).
Furthermore, higher long-term nonscreening rates were also significantly associated with higher subsequent cancer incidence. This includes a 1.61-unit increase in the 2014-2019 metastatic prostate cancer incidence rate per 10% increase in the 2010-2013 long-term nonscreening rate (p < 0.001).
