Unlocking the breast cancer puzzle

One in eight American women will be diagnosed with breast cancer.

Of these, one in five will die from the disease. Yet 70% of breast cancers are not associated with any known breast cancer risk factors. Why?

Chemicals can act like hormones

Scientists now believe that at least part of the answer may lie with chemicals called endocrine disruptors that are able to mimic the hormones our bodies produce. New research in the emerging field of epigenetics – literally “beyond genetics” – suggests that these chemicals interact with our genes to disrupt  our normal biological processes.  For women, these chemicals may play a role in the development of breast cancer.

Unfortunately, endocrine disruptors are everywhere—in detergents, antibacterial soaps, plastic containers, air freshener sprays and flame-resistant furniture. We take in these chemicals through our skin, the air we breathe, the food we eat. One of them, bisphenol A (BPA), is present in the bodies of some 90% of Americans, according to the Centers for Disease Control.

Chemicals affect young girls

Another class of chemicals, called phthalates, is used in everything from shower curtains to paints, intravenous tubing and blood bags. Several of them are known endocrine disruptors, linked to premature puberty and breast development in girls. These are risk factors for development of breast cancer later in life.

Chemicals can harm fetuses

Epigenetics research shows that prenatal and early childhood exposures can cause lifelong problems. Developing fetuses are especially vulnerable to endocrine disruptors. In studies on mice, prenatal and pubescent exposure to BPA led to harmful effects that persisted over a lifetime. Such increased sensitivity may elevate the risk of developing breast cancer.

Fighting cancer gets harder

For women who already have breast cancer, toxic chemicals can do further damage. For example, BPA and a number of alkylphenols—chemicals found in detergents and cleaners—have been shown to stimulate faster division and growth of breast cancer cells. BPA may also confer “chemoresistance” on breast cancer cells, reducing the efficacy of anti-cancer drugs.

We need stronger protection

The most important thing we can do to combat this troubling trend is to help reform America's outdated and ineffective chemical safety law and ensure that chemicals are tested for toxicity before they are used in products we buy.