New study of US military veterans indicates effects of PSA testing policy

A new study presented to the American Society for Radiation Oncology (ASTRO) throws further weight behind arguments for prostate cancer screening.  The large longitudinal analysis, involving five million American military veterans, found that in health centres where screening was encouraged, later diagnosis of advanced malignancies was less likely.

“Screening rates were significant predictors of metastatic cancer rates,” said study leader Brent Rose of the University of California, San Diego at the annual ASTRO meeting in San Antonio, Texas.

The study found that, because of concerns about overdiagnosis of prostate cancer, overall rates of PSA test screening in men over 40 at Department of Veteran Affairs facilities dropped from 47.2% in 2005 to 37.0% in 2019.

During that period, metastatic prostate cancer rates rose from 5.2 per 100,000 men to 7.9 per 100,000, the researchers said. At individual centres, higher rates of screening were linked with lower rates of subsequent diagnoses of advanced cancers. For every 10% decrease in screening, there was a corresponding 10% increase in metastatic prostate cancer incidence five years later.

In the United States, health regulatory bodies have been wary of recommending prostate cancer screening because of the risk of diagnosing tumours that would ultimately do no harm, but Rose noted that their advice had resulted in rates of metastatic cancer rising “more dramatically” than overdiagnosis rates.