Our world is full of man-made chemicals and pollutants, and some experts and women have long suspected that routine exposure can raise breast cancer risk.
Preliminary research has been troubling: One study on mice showed that exposure to BPA, a chemical commonly found in plastics, promotes cancerous changes in cells.
But late last year, the nonprofit Institute of Medicine (IOM ) performed an exhaustive review of the available research and was unable to confirm a link between breast cancer and environmental toxins.
How concerned should we be?
Debbie Saslow, Ph.D., director of breast and gynecologic cancer for the American Cancer Society: "While the IOM review was well done, there's a big difference between not having enough evidence to prove a connection and having enough evidence to prove there isn't a connection."
Susan Love, M.D., founder and president of the Dr. Susan Love Research Foundation and clinical professor of surgery at the David Geffen School of Medicine at UCLA: "To date, almost all of these studies have been performed on animals. Until more research is done on women, we can't rule out an environmental link. This is something we're investigating now at the Dr. Susan Love Research Foundation, including ways to set up virtual human models to study the effect of potential carcinogens in the milk duct. That's the kind of research that will help clarify this complex issue."
Larry Norton, M.D., deputy physician-in-chief for breast cancer programs at Memorial Sloan-Kettering Cancer Center, New York: "Reading the IOM report reminds me of how hard it was to prove the link between smoking and lung cancer back when smoking was so common: There was no good control group of unexposed individuals! Most people have some level of exposure to toxins every day, so where can we find the control group for this issue? If there is an environmental link, we may need to look for it in the laboratory, not in observational data."
Marisa Weiss, M.D., president and founder of Breastcancer.org and director of breast radiation oncology and breast health outreach for Lankenau Medical Center, Pennsylvania: "The majority of breast cancers aren't caused by inherited genetics, which suggests that environmental factors do play a role. Even without conclusive evidence, I believe it makes sense to reduce your chemical exposure: Buy foods grown without pesticides and added hormones, store foods in glass containers or BPA-free plastic, regularly change air filters inside your home for better air quality, use natural cleaning products like vinegar and baking soda, and purchase paint and carpet labeled 'low VOC,' meaning they emit low levels of volatile organic compounds. These measures can't hurt—and might very well help."