Breast Cancer Risk Factors
Breast cancer is the most common invasive cancer in women worldwide. This year about 200,000 women in the U.S. will be diagnosed and 40,000 will die. The average woman living in the U.S. has a 12.1%, or a 1 in 8, lifetime risk of being diagnosed with breast cancer. Not only is breast cancer extremely prevalent, it is a complex disease with many risk factors. A family history of breast cancer or a genetic predisposition (such as BRCA 1 or 2 mutations) can significantly increase your risk for breast cancer. Personal reproductive history (such as age of menstruation and age at first childbirth) and lifestyle factors (such as weight, physical activity and alcohol consumption) also influence risk for developing breast cancer. About 75% of the women who develop breast cancer have no significant family history, and do not carry any of the known genetic risk factors. So, a large portion of breast cancer can be attributed to lifestyle factors and environmental exposures.
Environmental Risk Factors
Exposure to certain chemicals in the environment can potentially increase the risk of developing breast cancer. This includes chemicals in the air, water, food, in household products, and in everyday items such as plastics. The impacts of exposure to environmental toxins on cancer development are complicated. The effects are dose related but in some cases with unexpected and profound changes at very low doses. The response to environmental toxins may also be age-related with exposure during pregnancy resulting in different outcomes than exposure during puberty or during menopause.
An emerging public health concern is the environmental influence of the large number of either naturally occurring or man-made chemicals that may interfere with normal cellular functioning and hormone balance. These toxins are called endocrine disrupting chemicals or EDCs. They are similar to (or mimic) naturally occurring hormones in the body. They can interfere with growth and development, metabolism, and reproduction among other normal processes.
EDCs as well as other environmental factors may have profound effects on birth outcomes, development, and predisposition to diseases in adulthood. Exposure to EDCs have been associated with changes in the breast and reproductive organ development in both males and females, inappropriate brain development, inappropriate pubertal development, and increased sensitivity to carcinogens as adults. Exposure during puberty is associated with altered metabolism and with altered sensitivity to carcinogens and EDCs.
Some naturally occurring chemicals that may disrupt normal endocrine or hormone function include phytoestrogens found in soybeans, coffee, and other plants. Other man-made chemicals of concern are found in household goods, cosmetics, medicines, synthetic hormones, food additives, pesticides and industrial products such as plastics. For example, breakdown byproducts of detergents, cosmetics, plastics, and flame-retardants include dioxins, phthalates, PCBs, and bisphenol A (BPA). Many of these byproducts reach streams through runoff, industrial effluent, atmospheric deposition, and municipal sewage treatment effluent as well as direct human exposure.
Environmental Exposures and Breast Cancer Risk
We are learning more every day about how environmental exposures might interact to cause breast cancer and understanding who might be most susceptible to the effects of these chemicals. More work is needed to understand which environmental agents or combinations of agents are associated with breast cancer risk and how that risk can be prevented.
For more information on this topic check out The Breast Cancer Fund’s State of the Evidence 2010: The Connection Between Breast Cancer and the Environment. This report summarizes the scientific evidence linking exposures to chemicals and radiation in our everyday environments to increased breast cancer risk.
Learn More: Attend the Annual Breast Cancer Conference in Burlington on October 15
If you want to learn more about the link between breast cancer and the environment, check out the Annual Breast Cancer Conference here in Burlington on October 15th. The theme of this year’s Annual Breast Cancer Conference focuses on the link between breast cancer and the environment. The conference will include over 50 educational sessions and interactive workshops conducted by breast cancer experts and health care professionals from throughout the region. Specific talks relating to breast cancer and the environment include:
- Cancer and the Environment— What is the Connection?
Speaker: Patricia O’Brien, M.D.
- Gene-Environment Interactions and the Development of Cancer
Speaker: Barry Finette, M.D., Ph.D.
- Bench to Bedside Translational Research
Speaker: Frances Carr, Ph.D.
The Annual Breast Cancer Conference is presented by the Vermont Cancer Center at UVM/the UVM Medical Center and will be held at the Sheraton Hotel and Conference Center in South Burlington on Friday, October 15th. This is a free community event open to the public and targeted for survivors, caregivers, and those whose lives have been touched by breast cancer.
For more information about the Annual Breast Cancer Conference visit or call 802-656-2292. Walk-ins are welcome however, space is limited and some sessions may be closed after the registration deadline on October 11th.
Marie E. Wood, MD, is a medical oncologist and is currently interim director of Hematology/Oncology at the UVM Medical Center. Her areas of expertise are breast cancer, cancer genetics, melanoma and oncology.