COMMENTARY: Breast Cancer’s Environmental Legacy

How Every Day Toxins Threaten Women’s Health

Breast cancer rates have nearly tripled in the U.S. over the past 60 years.© National Breast Cancer Research Institute

In 2005 it was estimated that 211,240 American women were diagnosed with breast cancer, and 40,410 women died from the disease. Breast cancer rates have nearly tripled in the United States over the last 60 years making it the second most common cancer in women. The lifetime risk for a woman to develop breast cancer in 1940 was 1 in 22. In 2006 it was up to 1 in 8, and has continued to rise. The probability of a woman contracting any form of cancer in the United States is an astonishing 1 in 3.

Similar increases can be seen in "developed" countries such as England, Japan, and Denmark. Within the European Union a woman dies of breast cancer every 7.5 minutes making it the number one killer of women between the ages of 34 and 54. These are "developed" nations, with increased screening through mammograms, breast exams, and regular doctor visits. What explains this drastic increase?

The genetic component of breast cancer (BRCA-1 and BRCA-2) plays an important role, yet how much of the recent increase in breast cancer does genetics actually account for? Ponder this: According to Harrison’s Principles of Internal Medicine, "Not more than 10% of human breast cancers can be linked directly to germline mutations" and the 2006 Current Medical Diagnosis & Treatment reports that "There is no history of breast cancer among female relatives in over 75% of patients." New research now points out that the BRCA-1gene isn’t all negative and it actually plays a role in DNA repair, protecting a woman from breast cancer. Therefore, the recent climb in breast cancer rates cannot be solely explained by genetics.

A fact worth exploring in Harrison’s Principles of Internal Medicine (2005) is "the risk [of breast cancer] is higher among women born after 1940, presumably due to promotional effects of hormonal factors." Breast tissue is estrogen-dependent, this is why the breasts will become larger when a woman takes birth control pills or becomes pregnant. Besides estrogens the body makes there is also a substantial number of estrogen mimicking, disrupting and promoting substances, both natural and manmade, that we are exposed to in our environment every day. This poses a significant question: are environmental toxins acting on the breast tissue and increasing your risk of cancer? A plausible answer is given by Colbom et. al. "because total estrogen exposure is the single most important risk factor for breast cancer, estrogenic chemicals, toxins and compounds, which would add to this lifelong exposure, are an obvious suspect when searching for the cause of rising rates (of breast cancer) over the past half century." Although no firm data correlation exists across all breast cancer cases it is certainly more than plausible that estrogen and estrogen like substances are contributing to the increase in these cancers in the modern era.

Rachel Carson"s book Silent Spring, warned about toxic chemical exposures in the 1960s.© Manhattan Rare Books

History will show us that the idea of industrial and environmental toxins inducing cancer is not a new one. We have known for over a hundred years that manmade chemicals can cause cancer. Way back in 1895 aniline dyes, made from coal tar, were proven to cause bladder cancer. Later, during the environmental movements of the 1960s, Rachel Carson wrote Silent Spring. In this book she exposed the known and proposed health hazards of the pesticide DDT while also warning us about many other chemicals that surround us every day. Since the writing of the book, research has mounted in support of her claims.

Between 1938 and 1971, an estimated 5 to 10 million pregnant women in the United States were encouraged to take DES (Diethylstilbestrol), a synthetic estrogen, which was originally prescribed by doctors for women who were at risk for miscarriage. Not coincidentally, in 1970, a rare cancer called Clear Cell Adenocarcinoma (CCA) began to show up in unprecedented numbers of young women. Studies were performed to answer the rising number of questions and in 1971 and 1972 DES was identified as a cause of this cancer in young women who had been exposed to DES in the womb. Researchers have also found that DES daughters are 40 times more likely to develop cancer of the vagina and cervix than women who were not exposed to the drug. We know estrogenic compounds can cause and promote cancer.

Medical research is mounting a huge collection of evidence showing that our environment, and the toxins we are all exposed to, increases the likelihood of breast cancer and cancer in general. Studies show that hormone (endocrine) disrupting chemicals can act together and that small, seemingly insignificant quantities of individual chemicals can have major cumulative effects on the body. Multiple estrogenic chemicals can collect in the body and act together to produce unknown effects, even when each individual component is believed to be within the considered "safe zone" set by the EPA. Endocrine disruptors are chemicals capable of disrupting the normal functioning of the endocrine system, and may pose a growing threat to human and wildlife health. These compounds can modulate both the endocrine and immune systems resulting in alteration of homeostasis, reproduction, development and behavior. The endocrine and reproductive effects of these chemicals are believed to be due to their ability to: (1) mimic the effect of endogenous (produced in the body) hormones, (2) antagonize the effect of endogenous hormones, (3) disrupt the synthesis and metabolism of endogenous hormones, and (4) disrupt the synthesis and metabolism of hormone receptors.

Synthetic estrogen taken between 1938 and 1971 led to a wave of young women with a rare form of cancer.© Getty Images

From heavy metals to industrial accidents to conventional medicine, your body is being exposed to and storing these endocrine disruptors. Studies have shown the heavy metal cadmium (Cd) mimics the effects of estradiol in estrogen-responsive breast cancer cell lines. Cadmium is found in cigarette smoke, certain art supplies, and is usually a component of air pollution produced by traffic. A study of 981 Italian women who were exposed to dioxin, from an industrial explosion in 1976, showed a significantly increased risk of breast cancer when evaluated. Antibiotics have been instrumental in our health, in certain situations, yet when over prescribed they stress the liver, create dysbiosis (imbalance of bowel flora) and leave residues or metabolites that can add to the toxic mixture in your body. According to the Journal of the American Medical Association, "When they analyzed all the information they were able to gather, the researchers found that the more antibiotics women used, the greater their breast cancer risk was."

With all of this information and research helping us to understand how our environment can be increasing our risk of breast cancer, among other diseases, it seems only logical to take steps to protect your loved ones and ourselves. The environmental medicine movement is picking up momentum and people are beginning to understand that we really do live in a toxic world. "The world that surrounds us; including the air we breathe, the food we eat, and the water we drink; is full of toxins. Many of these toxins are known carcinogens (cancer causing), and the vast majority have never been studied for their effects on humans," says the site breastcancer.org. The effects on the body are complex and are influenced by many factors, including the route and site of exposure (skin, oral, injection, inhalation etc), the timing, the duration and frequency of exposure, and the susceptibility of the individual exposed. Although, some of the pieces are still unclear, we do know that there are many chemicals in our environment that cause cancer. We also know that everyone has t

hese toxins, to some degree, stored in their body. "Our findings revealed that under the current regulatory system, toxic chemicals from consumer products and industrial pollution contaminate each of us and threaten our health," writes Erika Schreder of the Toxic-Free Legacy Coalition.

We need to start the movement of prevention in the breast cancer world, and I don’t mean things like preventive mastectomies. Find a physician who is trained in preventative medicine because breast exams and mammograms only detect, they do not prevent breast cancer. Detection without prevention is like standing on the train tracks, watching a train roll towards you, and being content that after you get hit the medical community will try to put you back together. When possible, use prevention, and step off the tracks.

DR. GARRETT WDOWIN practices naturopathic medicine in Arizona.

CONTACTS: Breastcancer.org; Toxic-Free Legacy Coalition