Background: Exposures to arsenic (As) and cadmium (Cd) have been associated with higher prostate cancer (PC) mortality; however, these associations have been inconsistent. The authors investigated whether higher ambient air concentrations of As and Cd are associated with lower overall and PC-specific survival among PC cases in Pennsylvania.
Methods: Incident PC cases of patients, aged 40 years or older, with a clinical diagnosis and nonmetastatic disease were identified in the 2004 to 2014 Pennsylvania Cancer Registry. Demographic, clinical, and pathologic information were extracted from the Pennsylvania Cancer Registry. The 3- and 5-year average and cumulative air concentrations of As and Cd were extracted from the Environmental Protection Agency’s Toxics Release Inventory database. Spatial-temporal hierarchical accelerated failure time models were used to examine the associations between air concentrations of As and Cd and overall and PC-specific survival for the total population and stratified by geographical region defined by rurality and Appalachia status, after adjusting for confounders.
Results: There were 78,914 PC cases included. Increasing 3- and 5-year average and cumulative air concentrations of As and Cd were significantly associated with lower overall and PC-specific survival among cases, after adjusting for confounders, for the total population, and stratified by geographical region for most of the estimates.
Conclusions: Data suggest that increasing ambient air exposures to As and Cd may play a role in overall and PC-specific mortality risk among PC cases. Exposures to As and Cd are modifiable and may provide insight into potential strategies to improve PC health outcomes.
Lay summary: Arsenic and cadmium exposures linked to increased prostate cancer deaths remain unclear. We investigated whether air levels of arsenic and cadmium reported to be released from industries decrease overall and prostate cancer-specific survival among prostate cancer cases identified in the 2004 to 2014 Pennsylvania Cancer Registry. Among the 78,914 prostate cancer cases, increasing air levels of arsenic and cadmium are found to be associated with lower overall and prostate cancer-specific survival for the total population and within rural and urban Appalachia and urban non-Appalachia counties in Pennsylvania. Reducing exposures to arsenic and cadmium have the potential to decrease prostate cancer deaths.
Keywords: air exposures; arsenic; cadmium; overall survival; prostate cancer-specific survival.