In a large study of men receiving care at Veterans Health Administration (VHA) medical centers, investigators found that facilities with higher PSA screening rates had lower subsequent rates of metastatic prostate cancer.
Metastatic prostate cancer incidence within the VHA system rose from 4.6 cases per 100,000 men in 2008 to 7.9 per 100,000 in 2019. Each 10% increase in PSA screening rate was significantly associated with a 9% decrease in the incidence of metastatic prostate cancer 5 years later, Alex K. Bryant, MD, a radiation oncology resident physician at the University Michigan Rogel Cancer Center in Ann Arbor, and colleagues reported at the 2022 American Society for Radiation Oncology (ASTRO) annual meeting in San Antonio, Texas. Each 10% increase in long-term non-screening rates (the percentage of patients who missed screenings 3 years in a row) was significantly associated with an 11% increase in the incidence of metastatic prostate cancer 5 years later. Study results were published concomitantly in JAMA Oncology.
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 metastatic prostate cancer, Dr Bryant and colleagues concluded.
Over the past 12 years, conflicting data and changes in clinical practice guidelines have led to a drop in PSA screening rates across the country, the investigators noted. Dr Bryant and colleagues analyzed data from all men aged 40 years or older receiving care at 128 facilities in the VHA health system from January 1, 2005 to December 31, 2019.
The cohort grew from 4,678,412 men in 2005 to 5,371,701 men in 2019. PSA screening rates declined system-wide from 47% in 2005 to 37% in 2019. Investigators observed declines across all ages and races. During this same period, long-term non-screening rates increased across the VA health care system.
Douglas M. Dahl, MD, Chief of the Division of Urologic Oncology at Massachusetts General Hospital Cancer Center and Associate Professor of Surgery at Harvard Medical School, both in Boston, said the VHA population is a good way to capture evidence across a national health system in the United States. The results are consistent with other data showing the detrimental impact of the US Preventive Services Task Force (USPSTF) 2012 grade D recommendation against PSA screening.
“Metastatic [prostate cancer] rates have been on the rise since then after decades of progress,” Dr Dahl said. “I think a new and really important finding is the 3-year gap in screening also being tied to increased metastatic rate. This is so relevant to the COVID-related disruptions in early detection which will also likely show downstream negative effects. We are seeing so many men with aggressive tumors who unfortunately did not get routine medical care due to the pandemic.”
While the USPSTF changed back to a grade C recommendation, Dr Dahl said significant damage occurred. “Much of the foundation for recommendations against screening are no longer valid,” Dr Dahl said. “It used to be that any abnormal PSA automatically meant a biopsy. Now, we have MRI done prior to biopsy, which results in differentiating very well between those who need biopsy and those who don’t.”
The use of transperineal biopsy has nearly eliminated the risk of serious infections or bleeding due to biopsy, according to Dr Dahl. With MRI guidance, he said biopsies are substantially more accurate in making a diagnosis so appropriate treatment or surveillance can be tailored to the situation. “It used to be any diagnosis of prostate cancer automatically meant aggressive treatment,” he said. “Now, a large cohort of our patients are monitored instead of having treatment. This is widely accepted and found to be safe.”
Philipp Dahm, MD, Professor of Urology and Program Director & Urology Vice-Chair of Education and Veterans Affairs at the University of Minnesota in Minneapolis, said he does not think any guidelines will be changed because of this study. The study was uncontrolled and observational, so the data from it is not the type to prove or disprove the benefits and harms of screening.
“It is noteworthy that this study focused on the incidence of metastatic prostate cancer, which is not the same as death from prostate cancer,” Dr Dahm said. “I’d be curious to learn what happened to mortality. It may not have changed. My biggest issue with this and several other studies is the one-sidedness of the presentation that focuses only on select outcomes.”
Bryant K, Lee KM, Alba PR, et al. Association of prostate-specific antigen screening rates and subsequent metastatic prostate cancer incidence in a national healthcare system. Presented at: ASTRO 2022 annual meeting, October 23-26, 2022, San Antonio, Texas. Abstract 298.
Bryant K, Lee KM, Alba PR, et al. Association of prostate-specific antigen screening rates with subsequent metastatic prostate cancer incidence at US Veterans Health Administration facilities. JAMA Oncol. Published online October 24, 2022. doi:10.1001/jamaoncol.2022.4319