At a unique session during the Society of Toxicology’s 40th annual meeting in March, toxicologists evaluated new techniques for identifying breast carcinogens. The scientists also expressed hope that these techniques could help lead to breast cancer risk reduction. Speakers at the session, “Breast Cancer: Issues in Screening and Testing of Potential Human Carcinogens,” reviewed the importance of a girl’s or woman’s developmental stage at the time of an environmental exposure and differences in individual susceptibility to chemical exposures. They also emphasized the most urgent needs in gender-specific risk assessments.
Based on evidence from animal models, some of the compounds the speakers identified as prime suspects for human studies included common solvents such as benzene and methylene chloride and pesticides such as dichlorvos and dichloroethane. Other chemical suspects that they reviewed are found in textiles, dyes, paint removers, antiknock agents, flame retardants, and air pollutants.
Among the speakers was Christine Ambrosone of the Mt. Sinai School of Medicine, who urged new epidemiologic studies to take into account common genetic variations that affect the metabolism of pollutants. In a discussion about the timing of exposures, Sue Fenton of the U.S. Environmental Protection Agency presented studies showing that prenatal dioxin exposure permanently affects mammary gland development in rats, leaving the animals more susceptible to tumors in response to other chemical exposures.
The session was co-chaired by Ruthann Rudel, senior scientist at Silent Spring Institute, and Barbara Davis, director of the Laboratory of Women’s Health Research at the National Institute for Environmental Health Sciences. Rudel’s presentation pointed out that although chemical exposures may account for only a small percentage of new diagnoses, controlling exposures to carcinogens could provide women with one of their only means to prevent breast cancer. She also noted that many of the 65 chemicals that are classified as known human carcinogens were identified from occupational studies. Because worker studies have rarely included women, she said, breast carcinogens have not yet been identified in this way. “This session provided new direction for the development of more sensitive and efficient methods to identify breast carcinogens,” Rudel added. ■
Just a few weeks after being diagnosed with breast cancer, Pat Hunt attended a Silent Spring Institute information session at her church on Cape Cod and immediately became involved, first as a volunteer and then as a member of the Institute’s Board of Directors. Her passionate activism was coupled with a quiet grace and elegance. Pat died of breast cancer in May 2001. She was one of a kind, and she will be sorely missed.
—Julia Brody, PhD
SILENT SPRING REVIEW