The effect of race on progression-free survival in patients with metastatic hormone-refractory prostate cancer (HRPC): a pooled analysis of CALGB studies.

4573 Background: To determine if African-American (AA) men have different progression-free survival (PFS) than non-African-American (non-AA) patients with hormone refractory prostate cancer (HRPC). METHODS: Data from eight multicenter trials (four phase II and four randomized phase III studies) conducted by the Cancer and Leukemia Group B (CALGB) from 1992-2002 were combined. Eligible patients had progressive adenocarcinoma of the prostate after androgen ablation (with castrate testosterone levels), an ECOG performance status of 0-2, and adequate hematologic, renal and hepatic function. PFS was defined as the time to objective progression, PSA progression using the PSA consensus criteria, or death, whichever occurred first. A proportional hazards model was used to assess the prognostic importance of race adjusting for important baseline factors. RESULTS: Of the 1216 patients, 173 (14%) patients were AA and 1043 (86%) were non-AA. AA men were younger [median: in AA= 69 years, inter-quartile range (IQR) 63-75; in non-AA=71 years, IQR=65-76; p-value =0.01], had shorter interval between diagnosis and study entry (median=3 years, IQR=2-5, vs. 4 years, IQR=2-6; p-value=0.03), higher PSA levels (median=190, IQR=44-524, vs. median=100, IQR=36-286; p-value<0.01), and lower hemoglobin levels (median=11.7, IQR= 10.4-12.5 vs. 12.6, IQR=11.4-13.5; p-value<0.01). There was no statistical difference between the two groups in the proportion of patients with Gleason sum of 8 or higher (51% vs. 44%, p-value=0.10). The median time to progression was 3.44 months (95% Confidence Interval (CI)= 2.66-4.01) for AA compared to 2.69 months (95% CI= 2.54-2.86, p-value=0.58). In the multivariate analysis, adjusting for age, years since diagnosis, performance status, PSA, LDH, Gleason sum, and hemoglobin, the hazard ratio was 0.86 (95% CI= 0.73-1.03; p-value = 0.10) for AA compared to non-AA men. CONCLUSIONS: There was no statistical significance difference in PFS between AA and non-AA men with HRPC enrolled on these clinical trials. It is unknown if these results would hold true in a less selected patient population. No significant financial relationships to disclose.

Duke Scholars

Author Susan Halabi Biostatistics & Bioinformatics, Division of Biostatistics