Traditional prognostic variables, such as increasing age, serum hemoglobin time to the development of androgen-independent disease, osseous stage, the number of organ systems with metastases, and treatment group, were independent prognostic factors for survival in men with AIPC; racial group was not.
The majority of studies evaluating the relationship of race with disease-specific survival in men with advanced (but not specifically androgen-independent) prostate cancer are consistent with our data. In a study by Brawn and coworkers based on an equalaccess military healthcare system, African-American men presented with stage-D prostate cancer at a rate of 52%, compared with 26% in Caucasian men. Although African-American men demonstrated decreased overall survival, given the advanced pathologic stage of their disease, there was no difference in mortality between African-American and Caucasian men after adjusting for tumor grade and stage. Similarly, as part of the Casodex Combination Study Group, McLeod et al. performed a double-blind, randomized, multicenter trial comparing combined androgen blockade consisting of a luteinizing hormone-releasing hormone analogue (LHRHa) plus, in 813 patients with stage-D2 prostate cancer. At a median follow-up of 160 weeks, there was no association between race or type of oral canadian antiandrogen used and time to progression or overall survival. Similar findings were reported by Fowler and colleagues in a nonrandomized study comparing serum PSA response after hormonal ablation in 217 African-American and 188 Caucasian men with prostate cancer. In this study, there were no racial differences in the time to PSA nadir or in PSA doubling time after adjusting for clinical stage and pretreatment PSA.
Similarly, the PSA response to deferred androgen blockade or antiandrogen withdrawal was the same in African-American and Caucasian men. These data contrast with those of two other studies in which African-American identity was an independent adverse prognostic factor for survival in patients undergoing therapy for distant metastases. In the National Cancer Institute Intergroup Study #0036, African-American men (n=107) were noted to have decreased survival (26.4 months) compared with Caucasian men (n=442, 33.6 months). Similar findings were reported by Thompson and colleagues as part of the Southwest Oncology Group (SWOG) Study 8894, a randomized phase III trial of 1,263 patients comparing orchiectomy with or without flutamide canadian in men with metastatic prostate cancer. African-American men (n=288) had more advanced disease and bone pain at presentation, worse performance status, higher Gleason score and serum PSA, and younger age at study entry. On multivariate analysis, African-American identity persisted as a modest independent prognostic factor for decreased survival (hazard ratio=1.23). However, the decreased survival of African-American men in these two latter studies may be accounted for by the disproportionate number of African-American patients with significantly advanced disease at presentation. In contrast to the current study, neither of these studies included the extent of metastatic disease, as determined by osseous stage or the number of bone scan areas of increased intensity, as independent factors in their multivariate model.
Subsequently, an in-depth analysis of independent prognostic factors was performed on the SWOG 8894 data set, which included variables related to the extent of disease in bone and other variables. After adjusting classification and regression tree analysis, the four factors that remained significant included the presence of appendicular (versus axial) metastases, performance status, serum PSA concentration and Gleason score. Utilizing these variables as predictors, race was no longer a significant variable affecting outcome. Of note in the present series, the presence of appendicular (osseous stage 2) metastases was also an independent prognosticator of poor survival (Table 3). canadian antibiotics
While differences in the extent of disease in bone, number of metastatic sites, treatment group assignment or time to AIPC were not detected by race, both African-American and Hispanic patients were younger than the Caucasian cohort. In the case of African-American patients, younger age at onset, as well as genetic, pathologic, molecular and socioeconomic aspects compared with other racial groups have previously been reported. While the present study found no racial difference in survival for men undergoing treatment for AIPC, it does not address differences in the biology of prostate cancer that may be related to differences in the earlier onset of the disease. This remains an important area of investigation.
The present study summarizes our experience with a consecutive series of Caucasian, African-American and Hispanic patients with AIPC and reveals the importance of utilizing relevant parameters, such as patient age, extent-of-disease (i.e., in bone as well as a number of metastatic sites), serum hemoglobin level and response to prior hormonal therapy (as reflected by the time to AIPC) as stratification variables to evaluate the efficacy of novel therapeutic agents.