Introduction:

Prostate-specific antigen (PSA) screening was associated with reductions in metastatic prostate cancer and prostate cancer mortality in a large European screening trial, but not in a similar United States screening trial. There exists ongoing debate about the benefits and harms of PSA screening. We sought to evaluate the association of county-level PSA screening rates with county-level incidence of metastatic prostate cancer and prostate cancer mortality in the United States.

Methods:

This ecological study used data from the 2004-2012 Behavioral Risk Factor Surveillance System (BRFSS) to build a multilevel mixed effects model with poststratification using US Census data to estimate county-level PSA screening rates for all 3,143 United States counties adjusted for age, race, ethnicity, and county-level poverty rates. The exposure of interest was average county-level estimated PSA screening rate from 2004-2012, defined as the proportion of men aged 40-79 who underwent PSA screening within the prior 2 years. The primary outcomes were age-adjusted incidence of regional/distant prostate cancer 2015-2019 and age-adjusted prostate cancer mortality 2016-2020, the most recently available county-level prostate cancer outcome data.

Results:

416,221 male BRFSS respondents aged 40-79 met inclusion criteria and were used in the multilevel mixed effects model. The model was post-stratified using 63.4 million men aged 40-79 from all 3,143 counties in the 2010 Decennial Census. County-level estimated PSA screening rates exhibited geographic variability (Figure 1) and were pooled at the state level for internal validation with direct BRFSS state-level estimates, showing strong correlation with Pearson correlation coefficients 0.77-0.90. A 10% higher county-level probability of PSA screening 2004-2012 was associated with 14% lower county-level incidence of regional/distant prostate cancer 2015-2019 (rate ratio 0.86, 95% CI 0.85-0.87, p<0.001, Figure 2) and 10% lower county-level prostate cancer mortality 2016-2020 (rate ratio 0.90, 95% CI 0.89-0.91, p<0.001).

Conclusion:

This population-based ecological study found that United States counties with higher rates of PSA screening had lower rates of metastatic prostate cancer and prostate cancer mortality at extended follow-up. These findings may inform shared decision-making regarding PSA screening.

Funding: N/A