Mediating Racial Disparities in Prostate MRI

Racial disparities have been identified in prostate MRI and may affect outcomes for Black men with prostate cancer. Researchers sought to identify mediators of racial disparities in prostate MRI use in diagnosing prostate cancer. The results were presented during the 2021 ASCO Annual Meeting.

The researchers queried the Surveillance, Epidemiology, and End Results (SEER) Medicare database to identify patients with localized prostate cancer between January 2008 and December 2015, looking for claims for prostate MRI during the six months before or after a patient’s prostate cancer diagnosis. They identified candidate clinical and sociodemographic mediators by their correlation with race and prostate MRI; this included the Index of Concentrations at the Extremes. Non-linear Multiple Additive Regression Trees (MART) models were implemented to determine what the direct and indirect relative effects were of the mediators.

Final analysis included 71,597 patients. Black patients with prostate cancer had a lower likelihood of undergoing prostate MRI than white patients (5.3% vs. 7%; unadjusted odds ratio, 0.75; 95% confidence interval, 0.67-0.84; P<0.001). Racial disparity in receipt of prostate MRI was due to variation in SEER region (33.1%), residence in a high poverty area (22.5%), residential segregation (ICE group, 17.2%), and dual eligibility for Medicaid (13.2%). Clinical and pathologic factors did not play a significant role.

“After accounting for the mediators, the direct effects of race accounted for 6.2% of the observed disparity in prostate MRI use,” the researchers stated.

They concluded, “Sociodemographic factors including geographic region, and area-level measures of income and residential segregation explain the majority of the observed racial disparity in the use of prostate MRI among older Americans with prostate cancer. The findings underscore that measurable structural factors can be readily identified that underlie racial disparity in access to emerging diagnostic tools for patients with cancer.”