Clinical outcomes in men of diverse ethnic backgrounds with metastatic castration-resistant prostate cancer

Background: We have shown previously in multivariable analysis that black men had 19% lower risk of death than white men with metastatic castration-resistant prostate cancer (mCRPC) treated with a docetaxel and prednisone (DP)-based regimen. The primary goal of this analysis was to compare progression-free survival (PFS), biochemical PFS, ≥50% decline in prostate-specific antigen (PSA) from baseline and objective response rate (ORR) in white, black and Asian men with mCRPC treated with a DP-based regimen. Patients and methods: Individual patient data from 8820 mCRPC men randomized on nine phase III trials to a DP-containing regimen were combined. Race used in the analysis was based on self-report. End points were PFS, biochemical PSA, ≥50% decline in PSA from baseline and ORR. The proportional hazards and the logistic regression models were employed to assess the prognostic importance of race in predicting outcomes adjusting for established prognostic factors. Results: Of 8820 patients, 7528 (85%) were white, 500 (6%) were black, 424 were Asian (5%) and 368 (4%) had race unspecified. Median PFS were 8.3 [95% confidence interval (CI) 8.2–8.5], 8.2 (95% CI 7.4–8.8) and 8.3 (95% CI 7.6–8.8) months in white, black and Asian men, respectively. Median PSA PFS were 9.9 (95% CI 9.7–10.4), 8.5 (95% CI 8.0–10.3) and 11.1 (95% CI 9.9–12.5) months in white, black and Asian men, respectively. Conclusions: We observed no differences in clinical outcomes by race and ethnic groups in men with mCRPC enrolled on these phase III clinical trials with DP.