Could Your ZIP Code Be a Risk Factor for Breast Cancer?

A woman’s environment may shape her health in ways science is only beginning to understand. According to researchers at Sylvester Comprehensive Cancer Center at the University of Miami, women living near Superfund sites — locations polluted by hazardous waste — were more likely to be diagnosed with aggressive breast cancers, including triple-negative breast cancer. These sites have been flagged by the EPA for cleanup due to potential threats to human health.

How the Study Came Together

The concern wasn’t abstract. It started with people in South Florida noticing troubling patterns. According to Sylvester researchers, members of their Community Advisory Committee raised alarms about the health of residents living near polluted neighborhoods. Women from these areas were speaking up, saying they felt something wasn’t right. The research team listened and got to work.

Using Sylvester’s SCAN360 data portal, they reviewed more than 21,000 breast cancer cases in Florida between 2015 and 2019. Their findings showed that women who lived in the same census tract as a Superfund site were about 30% more likely to be diagnosed with metastatic breast cancer.

In a related analysis, they found that women in these same neighborhoods were also at higher risk for developing triple-negative breast cancer—a subtype that is more aggressive, harder to treat and more likely to return after treatment. That risk climbed even higher for women exposed to elevated levels of PM2.5, a type of air pollution made up of fine particles that can get deep into the lungs.

What This Means for Breast Cancer Research

The research team, led by epidemiologist Dr. Erin Kobetz and molecular biologist Dr. Aristeidis Telonis, is pushing the conversation forward. They examined tumor tissue samples from women in the Miami area and found distinct molecular markers tied to environmental and social disadvantage. Women from areas with limited health resources — places with fewer clinics, parks, grocery stores or stable housing — were more likely to develop aggressive breast tumors. The team believes these social conditions may be “baked into” the biology of breast cancer.