Income inequality and treatment of African American men with high-risk prostate cancer

Abstract

Purpose: Definitive treatment of high-risk prostate cancer with radical prostatectomy or radiation improves survival. We assessed whether racial disparities in the receipt of definitive therapy for prostate cancer vary by regional income.

Patients and methods: A cohort of 102,486 men (17,594 African American [AA] and 84,892 non-Hispanic white) with localized high-risk prostate cancer (prostate-specific antigen >20 ng/ml or Gleason ≥ 8 or stage ≥ cT2c) diagnosed from 2004 to 2010 was identified in the Surveillance, Epidemiology, and End Results database. Income was measured at the census-tract-level. We used multivariable logistic regression to assess patient and cancer characteristics associated with the receipt of definitive therapy for prostate cancer. Multivariable Fine and Gray competing risks analysis was used to evaluate factors associated with prostate cancer death.

Results: Overall, AA men were less likely to receive definitive therapy than white men (adjusted odds ratio [AOR] = 0.51; 95% CI: 0.49-0.54; P<0.001), and there was a significant race/income interaction (Pinteraction = 0.016) such that there was a larger racial treatment disparity in the bottom income quintile (AOR = 0.49; 95% CI: 0.45-0.55; P<0.001) than in the top income quintile (AOR = 0.60; 95% CI: 0.51-0.71; P<0.001). After a median follow-up of 35 months, AA men in the bottom income quintile suffered the greatest prostate cancer mortality (adjusted hazard ratio = 1.47; 95% CI: 1.17-1.84; P = 0.001), compared with white men in the top income quintile.

Conclusions: Racial disparities in the receipt of definitive therapy for high-risk prostate cancer are greatest in low-income communities, suggesting that interventions to reduce racial disparities should target low-income populations first.

Keywords: African Americans; Health care disparities; Income; Prostate; Prostatic neoplasms.