Environmental inequities are a significant contributor to breast cancer disparities among Black women, highlighting the importance of considering those factors in screening outreach.
“Tennessee ranks the 12th highest in breast cancer mortality nationwide, with Black women bearing a disproportionately higher burden of mortality, nearly 42% higher than their white counterparts,” said Chunrong Jia, PhD, a professor of epidemiology, biostatistics and environmental health at the University of Memphis School of Public Health, in Tennessee. “We wanted to examine if the environmental factors related to where they live might play the role in their breast cancer onsets.”
Dr. Jia and her colleagues recruited 355 Black women between 20 and 88 years of age in Memphis from 2016 to 2018 (Int J Environ Health Res 2024 Sep 13. doi:10.1080/09603123.2024.2400702). Investigators were ultimately able to obtain full geographic data about 50 breast cancer cases and 157 controls, and their addresses were geocoded and linked to environmental and socioeconomic data. They focused on several potential environmental hazards, and found that proximity to high traffic and Superfund sites significantly increased breast cancer risk (odds ratio, 1.636 and 12.262, respectively).
Additional analyses also found that the women’s socioeconomic status was linked to those risk factors. “There’s a path from income level to these pollution sources and the onset of breast cancer,” Dr. Jia said. “Women with low socioeconomic status tended to live in neighborhoods closer to higher levels of traffic pollution and/or Superfund sites, and those women also have a higher risk of developing breast cancer.”
Dr. Jia noted that studies of breast cancer risk often focus on demographic or behavioral risk factors, such as age or alcohol consumption. “These factors do play a role, but often we pay less attention to environmental exposures that are largely out of people’s control,” he said. “They have no choice but to passively receive the exposure to these pollutants or environmental toxins in the neighborhoods in which they live, which are often economically disadvantaged.”
Initiatives to improve access to prevention, screening and treatment services, “coupled with pollution control efforts, are vital for reducing breast cancer burdens in such areas,” Dr. Jia told Pharmacy Practice News.
An Oncology Pharmacist’s Firsthand Experience
The study’s findings resonated with Sandra Cuellar, PharmD, BCOP, a clinical associate professor of oncology therapeutics at the University of Illinois Retzky College of Pharmacy, in Chicago. “There was a commercial medical sterilization plant called Sterigenics, located in Willowbrook, Ill., not far from where I live. It was shut down by the state in 2019, and a recent report from the CDC documented it to be a cancer hot spot because of the toxins that had been released”.
That report, released in November 2023 (bit.ly/4aVFwSa), evaluated health risks from breathing the cancer-causing gas ethylene oxide in outdoor air near the Sterigenics facility. It found that people living near the plant during the time it was in operation had an increased lifetime risk for cancer, estimated at four to 10 excess cancers per 10,000 people.
“Environmental risk factors that produce DNA-damaging toxins can contribute not only to breast cancer but to any type of cancer,” Dr. Cuellar said. “Additionally, it is well documented that industrial facilities that release harmful pollutants, and often do not disclose what is being released, are often situated near lower-income and marginalized communities.”
This phenomenon, known as environmental injustice, “disproportionately exposes these communities to higher levels of pollution and related health risks, including cancer,” she said. “When you combine these environmental factors with social determinants of health, such as access to preventive care, education and screening, this can combine to lead to diagnosis at later stages and worse outcomes.”
Given these risks, cancer education and screening programs are particularly critical in lower-income communities and those that may be at higher risk due to environmental factors, Dr. Cuellar noted. “The recommendation for mammogram screening now begins at the age of 40, and if someone may be at elevated risk because of their environment, they at minimum should be following that standard of care,” she said. “However, if someone has a family history of breast cancer, that screening and genetic counseling can and should begin much earlier.”
Drs. Cuellar and Jia reported no relevant financial disclosures.
This article is from the March 2025 print issue.