Incidence and mortality trends of metastatic prostate cancer: Surveillance, Epidemiology, and End Results database analysis.

INTRODUCTION: In the past decade, prostate cancer screening decreased, raising the concern of delays in diagnosis and leading to an increase in new cases of metastatic prostate cancer. This study evaluated whether these changes may have impacted trends in metastatic prostate cancer incidence and survival. METHODS: Metastatic prostate cancer diagnoses from 2008-2016 were identified from the Surveillance, Epidemiology, and End Results (SEER) 18 registries. Age-adjusted incidence rates per 100 000 were calculated by time periods and demographic variables. Two-year all-cause and prostate cancer-specific mortality were calculated for patients diagnosed from 2008-2014, and multivariable Cox proportional hazards models were used to evaluate the impact of demographic and clinical variables. RESULTS: Incidence rates of metastatic prostate cancer increased by 18% from 2008-2009 to 2014-2016 (incidence rate ratio [IRR]=1.18, 95% confidence interval [CI] 1.14-1.21). This trend was observed across multiple subgroups but was greatest in non-Hispanic Whites and patients living in counties 0-10% below poverty level. There was an overall decreased risk of all-cause and prostate cancer-specific mortality, but unmarried men and men living in counties >20% below poverty level showed statistically significant increased risk of prostate cancer-specific mortality. CONCLUSIONS: Non-Hispanic Whites and the wealthiest subgroups had the largest increase in incidence of metastatic prostate cancer since 2008. Despite trends of decreased risk of prostate cancer-specific mortality, we found certain populations experienced increases in mortality risk. Studies exploring the role of socioeconomic factors on screening and access to newer treatments are needed.