Researchers at Fox Chase Cancer Center and Lewis Katz School of Medicine at Temple University have identified factors that, if addressed, could decrease incidence of aggressive prostate cancer in areas where rates are highest — often Black communities with high rates of poverty.
“This study is meant to give us clues as to how we can do a better job of reducing the prostate cancer burden at a population level — what factors we can address, beyond screening, to reduce the cancer burden,” said Shannon Lynch, PhD, MPH, Assistant Director of the Office of Community Outreach and Engagement at Fox Chase, Co-Director of the Center for Biostatistics and Epidemiology at the Lewis Katz School of Medicine, and the study’s principal investigator.
Prostate cancer is the second leading cause of cancer deaths among men in the United States, and it disproportionally affects Black men, who are twice as likely to be diagnosed with and die of the disease. Catching this cancer in its early stages is key, as the five-year survival rate for an early-stage prostate cancer diagnosis is 98%, versus 31% for later-stage diagnosis, termed “aggressive prostate cancer” in this study.
Lynch and colleagues analyzed Pennsylvania Cancer Registry records of more than 97,000 men diagnosed with prostate cancer in the state between 2005 and 2017 to identify geographic clusters or neighborhoods where cancer burden was highest.
They then linked patient cancer registry data with data from the U.S. Census and the Environmental Protection Agency that included social determinant of health (SDOH) exposures in areas where those men lived related to poverty, access, and environmental exposures. They wanted to explore which area-level SDOH exposures were most closely associated with higher rates of aggressive prostate cancer.
From 37 area-level and four patient-level SDOH variables, the researchers coupled machine learning with geospatial modeling to narrow the list to the following variable domains that could largely explain the geographic disparities in aggressive prostate cancer in Pennsylvania:
- access (insurance);
- economic stability (poverty and employment);
- and built environment (related to environmental water quality).
In Philadelphia, for example, if the researchers adjusted for insurance or poverty in their models, aggressive prostate cancer clusters shrank or even disappeared. This suggests that improving access to care for patients and addressing SDOH could help eliminate the burden of aggressive prostate cancer in Philadelphia.
However, these findings were not uniform across the state. Unlike in Philadelphia, poverty and insurance didn’t account for clusters in Pittsburgh. There, prostate cancer disparities could only be accounted for by a water quality summary score. Lynch noted that they cannot say that water quality is causing clusters of aggressive prostate cancer because they are using area-level, more general measures of environment in this single-state study. However, what the findings could suggest, Lynch said, is that “even within the same state, our approach to addressing aggressive prostate cancer could potentially change depending on where you live.”
In Philadelphia, Fox Chase and Temple are already putting findings from this and similar studies into practice.
“We’re already starting to use mapping data like this to determine where and how to focus some of our prevention efforts. And we’re also utilizing this information to figure out, within our patients that come to the center, who may need some extra resources because they’re more at risk for poor outcomes because of where they live,” said Lynch. “We’re starting to not just identify where the burden may be, but how we can intervene to begin to make a difference.”
The paper, “An Exploratory Analysis of the Impact of Area-Level Exposome on Geographic Disparities in Aggressive Prostate Cancer,” was published in Scientific Reports.