Racial Disparities in Prostate Cancer Outcomes Differ by Geographic Region

A study examined how race plays a different role in prostate cancer patients depending on geographic region.

“Black men are more likely than white men to be diagnosed with and die of prostate cancer. Current evidence attributes this to racial differences in both tumor biology and access to care. These differences may also be greatest in specific disease states, such as low-risk prostate cancer,” the study authors explained.

The study examined data from 17 geographic registries within the Surveillance, Epidemiology, and End Results (SEER) database between Jan. 1, 2007, and Dec. 31, 2014. Eligible patients were biopsy-confirmed prostate cancer patients aged 18 years and older. Men with missing data including cancer stage, Gleason grade group, prostate-specific antigen level, and survival follow-up data were excluded from the study. The primary exposure was race, as reported in the SEER database. Prostate cancer-specific mortality was compared between black and white men. Patients were also stratified by Gleason grade: grade group 1 and grade groups 2 through 5.

Which Geographic Regions Have the Most Significant Disparities?

The majority of the study cohort was white (n=178,204; 77.6%); 15.2% of patients (n=35,006) were black, and race was unknown for the remaining 7.2% (n=16,561). The mean (SD) age at diagnosis among the entire cohort was 64.9 (8.8) years. Among white patients, 4,773 died of prostate cancer; 1,250 black men died of prostate cancer. Overall mortality risk was higher for black men compared to white men (adjusted hazard ratio [aHR]=1.39; 95% confidence interval [CI, 1.30 to 1.48). Stratified analyses revealed that black men had poorer prostate cancer-specific survival in four registries in Gleason grade group 1 (Atlanta, Georgia: aHR=5.49; 95% CI, 2.03 to 14.87; Greater Georgia: aHR=1.88; 95% CI, 1.10 to 3.22; Louisiana: aHR=1.80; 95% CI, 1.06 to 3.07; New Jersey: aHR=2.60; 95% CI, 1.53 to 4.40) as well as Gleason grade groups 2 through 5 (Atlanta:aAHR=1.88; 95% CI, 1.46-2.45; Greater Georgia: aHR=1.29; 95% CI, 1.07 to 1.56; Louisiana: aHR=1.28; 95% CI, 1.07 to 1.54; New Jersey: aHR=1.52; 95% CI, 1.24 to 1.87). In Gleason grade group 1, the most significant race-based survival difference was observed in the Atlanta registry.

The study was published in JAMA Network Open.

“After adjusting for patient, disease, and treatment characteristics, this cohort study found that population-level differences in prostate cancer survival among black and white men in the US were associated with a small set of geographic areas and with low-risk prostate cancer,” concluded the study authors. “While the cause of racial disparities in prostate cancer survival remains a topic of ongoing study, future studies and interventions should be targeted at settings where racial disparities are most pronounced.”