Association between environmental quality and prostate cancer stage at diagnosis

Prostate cancer (PC) etiology is up to 57% heritable, with the remainder attributed to environmental exposures. There are limited studies regarding national level environmental exposures and PC aggressiveness, which was the focus of this study METHODS: SEER was queried to identify PC cases between 2010 and 2014. The environmental quality index (EQI) is a county-level metric for 2000-2005 combining data from 18 sources and reports an overall ambient environmental quality index, as well as 5 environmental quality sub-domains (air, water, land, built, and sociodemographic) with higher values representing lower environmental quality. PC stage at diagnosis was determined and, multivariable logistic regression models which adjusted for age at diagnosis (years) and self-reported race (White, Black, Other, Unknown) were used to test associations between quintiles of EQI scores and advanced PC stage at diagnosis.

The study cohort included 252,164 PC cases, of which 92% were localized and 8% metastatic at diagnosis. In the adjusted regression models, overall environmental quality EQI (OR 1.20, CI 1.15-1.26), water EQI (OR: 1.34, CI: 1.27-1.40), land EQI (OR: 1.35, CI: 1.29-1.42) and sociodemographic EQI (OR: 1.29, CI: 1.23-1.35) were associated with metastatic PC at diagnosis. For these domains there was a dose response increase in the OR from the lowest to the highest quintiles of EQI. Black race was found to be an independent predictor of metastatic PC at diagnosis (OR: 1.36, CI: 1.30-1.42) and in stratified analysis by race; overall EQI was more strongly associated with metastatic PC in Black men (OR: 1.53, CI: 1.35-1.72) compared to White men (OR: 1.18, CI: 1.12-1.24).

Lower environmental quality was associated with advanced stage PC at diagnosis. The water, land and sociodemographic domains showed the strongest associations. More work should be done to elucidate specific modifiable environmental factors associated with aggressive PC.