Why Cancer's Gaining on Us

For all the pink ribbons, breast-cancer awareness events, fund-raisers, and celebrations of "survivorship," the facts remain grim. In this country, a woman's lifetime risk of breast cancer is one in eight. In 1975, the risk was about one in 11.

Outside of skin cancer, breast cancer is the most frequently diagnosed cancer in women. It is estimated that in 2008 there will be 250,230 new cases of breast cancer among women. An estimated 41,000 women will die of metastatic breast cancer in 2008. Because we still do not know what the causes of breast cancer are, primary prevention remains an elusive goal while mammography and early detection are the focus of attention.

Since World War II, the proliferation of synthetic chemicals has gone hand-in-hand with the increased incidence of breast cancer. About 80,000 synthetic chemicals are used today in the United States, and their number increases by about 1,000 each year. Only about 7 percent of them have been screened for their health effects. These chemicals can persist in the environment and accumulate in our bodies. According to a recent review by the Silent Spring Institute in Newton, 216 chemicals and radiation sources cause breast cancer in animals.

Nearly all of the chemicals cause mutations, and most cause tumors in multiple organs and animal species, findings that are generally believed to indicate they likely cause cancer in humans. Yet few have been closely studied by regulatory bodies. There is concern about benzene, which is in gasoline; polycyclic aromatic hydrocarbons, which are in air pollution from vehicle exhaust, tobacco smoke, and charred foods; ethylene oxide, which is widely used in medical settings; and methylene chloride, a common solvent in paint strippers and glues.

There is also broad agreement that exposure over time to natural estrogens in the body increases the risk of breast cancer, so it is important to consider the role of synthetic estrogens in breast cancer development. Many other chemicals, especially endocrine-disrupting compounds -- chemicals that affect hormones, such as the ubiquitous bisphenol A, which is found in plastic bottles and cans -- are also thought to raise breast cancer risk. Endocrine-disrupting compounds are present in many pesticides, fuels, plastics, air pollution, detergents, industrial solvents, tobacco smoke, prescription drugs, food additives, metals, and personal-care products including sunscreens.

Is there definitive evidence that these substances cause breast cancer? Have they been sufficiently studied? Well, no. We need to know more about the timing, duration, and patterns of exposure, which may be as important as dosage. But shouldn't we do everything possible to reduce exposure to the suspected chemicals? Shouldn't we take precautionary measures, as we continue and deepen the research? In Massachusetts, the leading cause of death in 2006 was cancer. It is time for action.

In our state, the Alliance for a Healthy Tomorrow, a coalition of more than 160 organizations, has worked for the passage of the Safer Alternatives Bill, which would create a program to replace toxic chemicals with safer alternatives when feasible. The bill would establish a pragmatic, gradual approach to reducing health impacts from many of the toxic chemicals that we are exposed to in everyday life. The bill passed the Senate unanimously this year, but was not voted on by the House. The alliance will introduce it again in the 2009 legislative session.

Yes, we need early detection but also primary prevention, and, of course, effective treatments for those of us with extended disease. Rachel Carson, who herself died of breast cancer in 1964, said it best: "For those in whom [cancer] is already a hidden or a visible presence, efforts to find cures must of course continue. But for those not yet touched by the disease and certainly for the generations as yet unborn, prevention is the imperative need."