The Lack of Racial Survival Differences in Metastatic Prostate Cancer in National Cancer Data Base (NCDB): A Paradox Compared to Non-metastatic Disease

Abstract

Inconsistent findings have been reported in the literature regarding racial differences in survival outcomes between African American (AA) and Caucasian American (CA) patients with metastatic prostate cancer (PCa). To address the inconsistency, the current study inquired into a national database to determine whether racial differences exist among the target population. The purpose of this research is to find out if racial differences exist in the survival outcomes between AA and CA patients with metastatic PCa. This study retrospectively reviewed PCa patient data (N = 1,319,225) from the National Cancer Database (NCDB). The data were divided into three groupings based on the metastatic status: (1) no metastasis (N = 579,202) (2) bone metastasis (N = 29,639) and (3) metastases to locations other than bone, such as brain, liver, or lung (N = 952). Survival probabilities of AA and CA PCa patients with bone metastasis were examined through parametric proportional hazards Weibull models and Bayesian survival analysis. These results were compared with patients with no metastasis or other types of metastases. No statistically supported racial disparities were observed for AA and CA men with bone metastasis (p = 0.885). Similarly, there were no racial disparities in survival for those men suffering from other metastases (liver, lung, or brain). However, racial disparities in survival was observed among the two racial groups for non-metastatic group (p<0.001) or when metastasis status was not taken into account (p<0.001). The Bayesian analysis corroborates the finding. This research supports our previous finding and reveals that there are no racial differences in survival outcomes between AA and CA patients with metastatic prostate cancer. In contrast, racial disparities in the outcome continue to exist among non-metastatic PCa patients. Further research is warranted to explain this paradox.