Breast cancer rates had been steadily climbing since the 1940s until about 2002  but breast cancer rates decreased by about 2% between 1998 and 2007 in the U.S. However, this decrease was only among women aged 50 and older. One of the more news worthy items has been a significant decline in breast cancer in US women in 2003. According to data from the National Cancer Institute (NCI) registries, the incidence fell by 6.7%. Data from 2004 showed a leveling off with no real additional decrease. The decrease, which started in mid-2003, was seen only in women 50 years of age or older and was 2 to 3 times more evident in estrogen-receptor-positive cancers. The decreases were similar for localized disease and more advanced disease, and were more evident in primary breast cancers but not in contralateral second primary or later breast cancers. 
A woman’s lifetime risk of breast cancer has nearly tripled during the past four decades. After lung cancer, breast cancer is the second leading cause of cancer deaths in U.S. women today. About 1.3 million women will be diagnosed with breast cancer annually, and throughout the world, about one half million will die each year from the disease. Deaths from breast cancer have decreased sine 1990, and it is suspected that this is largely due to earlier detection and advances in treatment.
One of the most well known risk factors for breast cancer is having a first degree relative with the disease, but, less than one out of every 10 cases of breast cancer occurs in women born with a genetic predisposition. At least half of all breast cancers occur in women with no known risk factor.
We have increased understanding that breast cancer arises from a mix of multiple factors— some inherited and some acquired, that lead to genetic mutations, alterations in gene expression or damage to genes. It is now thought that there is not any single exposure or event that is responsible for this affect on genes but rather the timing, duration and pattern of exposure, as well as the dose of a damaging agent. Even a small dose of a carcinogenic agent can have a devastating effect if it is during a critical window of a body system/organ development.
More than 100,000 synthetic chemicals are in use in the U.S. today with another 1,000 or so added each year,  and more than 90% of them have never been tested for their effects on human health. 
Evidence that environmental factors cause breast cancer runs from published studies showing a lack of evidence such as the Long Island Breast Cancer Study Report,  to multiple laboratory, animal and human studies covering a wide array of implications including ionizing radiation, xenoestrogens, hormone replacement therapy, oral contraceptives, polycyclic aromatic hydrocarbons, DDT, solvents, polyvinyl chloride, bisphenol-A, polychlorinated biphenyls, dioxin, flame retardants, ethylene oxide, insecticides, phthalates, food additives, methyl mercury, nicotine , hormones used in cattle feed and more items each year.
Scientists, physicians, public health officials, politicians, activists and consumers of all walks of life have called for wide ranging changes in industry, the work place, our households and our personal habits in order to reduce the production of, use of and disposal of chemicals and exposures that are or may be associated with the increased risk of breast cancer. Unfortunately, there has been a large failure to act and change in all sectors–the personal, commercial and governmental. Too many individuals, for profit companies, politicians and government officials appear to base their decisions on the need for action based on absolute proof and a 95 percent certainty of cause and effect. While this may serve commercial interests and a short sighted view of the economy of a community, it is not the standard by which we should conduct ourselves when it comes to public health. It is time to make decisions based on possible harm rather than conclusive proof and follow the physician’s core principle of “do no harm”. Others might call this better safe than sorry or the precautionary principle. Whatever we call it, at the very least, we should require proof of the lack of negative health consequences before toxic chemicals are introduced into our bodies and our environment.
The “Breast Cancer Fund” and “Breast Cancer Action” have proposed a 10 point plan for reducing the risk of breast cancer:
- Establish environmental health tracking programs at state and federal levels
- Practice healthy purchasing by adopting precautionary purchasing laws at local, state and federal lands.
- Protect workers from hazardous exposures
- Educate the public about the health effects of radiation and how to reduce exposure to both ionizing and non-ionizing radiation
- Hold corporations accountable for hazardous practices
- Offer local, state and federal incentives for clean green practices
- Strengthen right-to-know legislation and public participation in decisions about toxic exposures
- Enforce existing environmental protection laws
- Require greater transparency in funding of scientific and medical training, research and publications
- Create a comprehensive chemicals policy based on the precautionary principle
Yes, there are known “environmental” lifestyle risk factors that we are easily in charge of— hi fiber/low saturated fat/high fruits and vegetables diets, low alcohol, increased regular exercise, stop smoking and optimal weight management.
We can each do more ourselves to reduce our risk from these environmental exposures and reduce the impact on ourselves, our family members, our friends, our community and Mother Nature that surrounds us. I recommend a personal action plan: use non-toxic cosmetics, health and body care items and home cleaning items. Do business with a “green” dry cleaner. Grow and/or purchase organic and pesticide free foods. Recycle more and use less— less plastic, wood, cardboard, metal, etc. It often comes down to awareness and then making simpler/safer choices for ourselves and regarding our impact on the environment around us.
 Parkin D, Bray F, Ferlay J, Pisani P. Global cancer statistics, 2002;CA: A Cancer Journal for Clinicians 1005;55:74-108.
 American Cancer Society Breast Cancer Facts and Figures 2008-2009
 Ravdin P, Cronin K, Howlander N, Chlebowski R, Berry D. A sharp decrease in breast ancer incidence in the United States in 2003. Breast Cancer Res Treat 2006; 100: Suppl: S2, a abstract.
 National Cancer Institute. Cancer and the Environment: What you need to know, what you can do. National Institutes of Health. 2003
 Bennett M, Davis B. The identification of mammary carcinogens in rodent bioassays. Environmental and Molectular Mutagenesis. 2002;39(2-3):150-157.
 Winn D. The Long Island Breast Cancer Study Project. Nature Reviews Cancer 2005 Dec;5(12):986-94.
 Gray, J. Breast Cancer Fund; State of the Evidence- The connection between the environment and breast cancer. 2010, 6th edition.