Links Found Between Exposure to Carcinogens and Aromatics from Fossil Fuels and Breast Cancer Risk

Editor's Note: Supported in part by the Renewable Fuels Association, this research project was carried out by The Hormel Institute, University of Minnesota; and the Energy Resources Center, University of Illinois Chicago.

ELLISVILLE, Mo., May 20, 2025 /PRNewswire/ -- How early can exposure to carcinogens (cancer-causing compounds) from burning fossil fuels have an effect? The answer may surprise you: in the womb.

"Aromatics from fossil fuels and breast cancer," a recent paper appearing in the scientific journal iScience, explores fossil fuels' polycyclic aromatic hydrocarbons (PAHs) and benzene, toluene, ethylbenzene and xylene (BTEX) aromatics in relation to breast cancer risk in humans.

"It is essential to reduce exposure to the products from burning fossil fuels to prevent breast cancer. We are studying if reducing BTEX exposure will reduce susceptibility to PAH induced breast cancer. One way to reduce BTEX compounds is to reduce exposure by adding ethanol to gasoline," said the author of the paper, Leena Hilakivi-Clarke, PhD, professor at The Hormel Institute, University of Minnesota.

In utero exposures to PAHs are shown to increase a daughter's later susceptibility to breast cancer. The exposure may:

• Cause an increase in the number of structures in which breast cancer initiation takes place. 
• Inhibit expression of tumor suppressor genes.
• Cause persistent gut dysbiosis, which then impacts immune cells in the tumor microenvironment. 

Among the early life environmental pollutants that may increase PAH-initiated breast cancer susceptibility are volatile aromatic BTEX compounds. As such, aromatics from fossil fuels are likely to be involved in causing breast cancer. Findings by The Hormel Institute and other investigators show that BTEX exposure levels can be significantly reduced by adding ethanol to gasoline. This demonstrates ethanol is a healthier alternative to volatile aromatic BTEX compounds. Implementing solutions is imperative to reversing breast cancer rate trends.

Breast cancer rates continue to rise annually, especially in young women. While familial risk plays a role, more than 80% of breast cancers develop sporadically, without any inherited mutations like BRCA1 and BRCA2.

The paper proposes two factors are needed for sporadic breast cancer to develop.

• Events that increase susceptibility for cancer initiation and progression.
• Exposure to compounds that can lead to DNA mutations. 

The paper also proposes for those with familial breast cancer, the two factors may be:

• Events that increase susceptibility for cancer initiation and progression.
• Inheritance of the germline mutation.

Breast cancer risk factors include, timing of puberty onset and menopause, age at first pregnancy, diet, and lifetime exposure to estrogens. These alone do not cause breast cancer. These factors can create vulnerability to environmental carcinogens that can lead to DNA mutations, including PAHs from fossil fuels, which can cause breast cancer.

You can read full the paper here:
https://www.cell.com/iscience/fulltext/S2589-0042(25)00465-1 

The paper is authored by Leena Hilakivi-Clarke, PhD, professor at The Hormel Institute, University of Minnesota, and Hormel Institute researchers Theresa Jolejole, PhD candidate; Joas Lucas da Silva, PhD, post-doctoral associate; and Fabia de Oliveira Andrade, PhD, senior scientist, are among the authors of the paper.

The research project is supported by 15 different ethanol and biofuels funding agencies and R01 #CA276775 from the National Cancer Institute.

About The Hormel Institute
The Hormel Institute is an independent biomedical research department within the University of Minnesota's Office of the Vice President for Research. Collaborative research partners include Masonic Cancer Center UMN (a Comprehensive Cancer Center as designated by the National Cancer Institute, NIH), Mayo Clinic, and many other leading research centers worldwide. The Hormel Institute, which tripled in size in 2008 and doubled again in size in 2016, is home to some of the world's most cutting-edge research technologies and expert scientists. Over the next few years, The Hormel Institute will broaden its impact through innovative, world-class research in its quest to improve human health.

About Leena Hilakivi-Clarke, PhD, professor at The Hormel Institute, University of Minnesota
Dr. Leena Hilakivi-Clarke's research involves studying breast cancer risk and mortality. She investigates how maternal diet, obesity and exposure to carcinogens and aromatics during pregnancy can pre-program offspring's risk of developing breast cancer. She also studies possible interventions that could be implemented either during pregnancy or to adult offspring to prevent their increased breast cancer risk and risk of breast cancer recurrence. Dr. Hilakivi-Clarke collaborates closely with computational modeling experts and has collaborated with epidemiologists to translate her preclinical findings to the clinic.

About the Research
The Hormel Institute has conducted and continues to conduct research regarding cancer risk and mortality, including related to gasoline, diesel and other fossil fuels, and current and potential solutions to lower cancer risk. In addition to Dr. Leena Hilakivi-Clarke's paper, this work includes An Assessment on Ethanol-Blended Gasoline/Diesel Fuels on Cancer Risk and Mortality and other ongoing research projects.

Contact:
BIOFUELS RESEARCH PROJECT Managers
Gail Dennison, MA CFRE
gaildenn@umn.edu
507-351-0957

Steffen Mueller, PhD
muellers@uic.edu
312-316-3498

SOURCE RENEWABLE FUELS ASSOCIATION