Race Does Not Affect Survival in Patients With Prostate Cancer Treated With Radiation Therapy

Recent evidence has shown that African American men with prostate cancer may have more radiosensitive disease with greater overall survival (OS) with radiotherapy compared to Caucasian men. We compared OS in African American and Caucasian men receiving radiotherapy utilizing the National Cancer Database.

African American or Caucasian men with N0M0 prostate adenocarcinoma diagnosed between 2004 and 2013 were selected and grouped into favorable and unfavorable risk based on clinical T-stage, clinical Gleason score, and prostate-specific antigen. Patients with favorable risk received brachytherapy or dose-escalated external beam radiation (EBRT); those with unfavorable risk received EBRT plus anti-androgen therapy with/without brachytherapy. African American and Caucasian men in each subgroup were propensity score-matched and analyzed for survival. Sensitivity analysis used treatment-race and age-race interaction terms.

27,150 patients met the inclusion criteria, with a median age of 68 (range=38-90) years and median follow-up of 59.93 (range=48-142.62) months. OS was equivalent between African American and Caucasian race in favorable risk [log-rank p=0.82; hazard ratio (HR)=0.928; 95% confidence intervaI (CI)=0.583-1.477, p=0.753] and unfavorable-risk subgroups (log-rank p=0.87, HR=1.078, 95% CI=0.843-1.379, p=0.550). No significant interaction existed between treatment and race for either cohort but there was a significant interaction between race and age in those with unfavorable risk (HR=1.046, 95% CI=1.009-1.084, p=0.015), with greater OS in those of Caucasian race ≤60 years (HR=0.320, 95% CI=0.137-0.752, p=0.009).

African American and Caucasian men have similar survival when treated with risk-appropriate definitive radiotherapy. However, younger (age ≤60 years) African American men with unfavorable risk have poorer survival than their Caucasian counterparts and may harbor a significantly different biology of disease.