Clinical outcomes in Caucasian (C), African American (AA) and Asian men with metastatic castration-resistant prostate cancer (mCRPC).

Abstract

186 Background: We have previously shown in multivariable analysis that African American (AA) men had 19% lower risk of death than Caucasian (C) men with metastatic castration resistant prostate cancer (mCRPC) treated with a docetaxel (D) prednisone (P) based regimen. The primary goal of this analysis was to compare progression-free survival (PFS) and PSA PFS in C men, AA men, and Asian men with mCRPC treated with a DP based regimen. Methods: Individual patient data from 8,820 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. The endpoints were PFS and PSA PFS. Per protocol definition of PFS was used in the analysis while PSA PFS was defined per PCWG3 criteria. The proportional hazards model was used to assess the prognostic importance of race in predicting PFS and PSA PFS, adjusting for treatment arm and prognostic factors that were common across the trials (performance status, and sites of metastases). Results: Of 8,820 patients, 7,528 (85%) were C, 500 (6%) were AA, 424 (5%) were Asian and 368 (4%) had race unspecified. Men with race unspecified were excluded from the analysis, leaving 8,452 men. Median PFS was 8.3 months (m) (95% CI = 8.1-8.5), 8.2 m (95% CI = 7.4-8.8), and 8.3 m (95% CI = 7.6-8.8) in C, AA and Asian men, respectively. In multivariable analysis adjusting for risk factors, the pooled hazard ratios for AA vs. C was 1.04 (95% CI = 0.94-1.15, p-value = 0.461) and 1.08 (95% CI = 0.96-1.21, p-value = 0.192) for Asian vs. C. PSA data were available for 6,685 (89%) C, 456 (91%) AA and 412 (97%) Asian men. Median PSA PFS were 9.7 m (95% CI = 9.4-10), 8.5 m (95% CI = 7.6-10) and 10.0 m (95% CI = 9.5-11.8) in C, AA and Asian, respectively. In multivariable analysis, the pooled hazard ratios were 1.05 (95% CI = 0.94-1.16, p-value = 0.408) for AA vs. C and 1.00 (95% CI = 0.82-1.22, p-value = 0.996) for Asian vs. C. Conclusions: There were no differences in PFS and PSA PFS outcomes in C, AA, or Asian men with mCRPC enrolled on these phase III clinical trials with DP. Clinical trial information: NCT00004001.