Reduced Racial Disparity as a Result of Survival Improvement in Prostate Cancer.

Prostate cancer is a cancer type associated with a high level of racial and socioeconomic disparities as reported by many previous studies. However, the changes in these disparities in the past two decades have not been systematically studied. In this study, we investigated the Surveillance Epidemiology End Results (SEER) data for prostate cancer patients diagnosed during 2004-2018. African Americans and Asians showed significantly better and worse cancer-specific survival (CSS), respectively, compared to non-Hispanic white individuals after adjusting for confounding factors such as age and cancer stage. Importantly, the data indicated that racial disparities fluctuated and reached the highest level during 2009-2013, and thereafter, it showed a substantial improvement. Such a change cannot be explained by the improvement in early diagnosis but is mainly driven by the differential improvement in CSS between races. Compared with Asians and non-Hispanic whites, African American patients achieved a more significant survival improvement during 2014-2018, while no significant improvement was observed for Hispanics. In addition, the SEER data showed that high-income patients had significantly longer CSS than low-income patients. Such a socioeconomic disparity was continuously increasing during 2004-2018, which was caused by the increased survival benefits of the high-income patients with respect to the low-income patients. Our study suggests that more efforts and resources should be allocated to improve the treatment of patients with low socioeconomic status.