In a new initiative aimed at breast cancer risk reduction, Susan G. Komen for the Cure funded the Environment and Breast Cancer: Science Review to assess scientific research on environmental exposures and nonhereditary factors that may increase breast cancer risk. Finding risk factors we can change is particularly important as breast cancer is the leading cause of death for American women from their late 30's through their early 50's.

The series of five articles was published in a supplement of the journal Cancer on May 14, 2007. The studies were done by Silent Spring Institute, with additional researchers from Harvard University, Roswell Park Cancer Institute and the University of Southern California.

The researchers synthesized national and international data sources and identified 216 chemicals that caused breast tumors in animal studies, and several chemicals that have been linked to breast cancer in humans. They used this information to create a comprehensive, searchable online database with details on potential breast carcinogens.

The database shows that among the 216 compounds that cause breast tumors in animal tests:

• 73 have been present in consumer products or as contaminants in food
• 35 are air pollutants
• 25 have been associated with occupational exposures affecting more than 5,000 women a year
• 29 are produced in the U.S. in large amounts, exceeding 1 million pounds per year

The database are accessible free of charge and include references to 900 studies, 460 of which are human breast cancer studies that were critically evaluated by the research team.

Silent Spring Institute's analysis also shows that the overwhelming majority of chemicals people are exposed to have never been tested for cancer risk; they concluded that more research is needed to expand and improve chemicals testing. Komen for the Cure has embraced the position that because breast cancer is common and the environmental chemical exposures that may affect risk are so widespread, reducing such exposures may help a significant number of women.

The Silent Spring Institute study also examined lifestyle influences on breast cancer, such as physical activity and diet. Results underscore the importance of regular, life-long physical activity to lower a woman's risk of developing breast cancer. Reducing alcohol consumption and avoiding weight gain or being overweight after menopause also lower risk. The study concluded that further research is needed to determine the relationship between dietary factors and breast cancer risk.

go to the databases