The National Cancer Institute needs to publish information about chemical exposure and cancer risk

Our government should take the steps it can to protect Americans from a public health crisis that is claiming thousands of lives. We aren’t just talking about Covid-19 here. We are talking about breast cancer.

Research has linked more than 200 commercial chemicals to the risk of developing breast cancer. This work is from observational studies in people and the ability of these chemicals to cause mammary gland tumors in animal studies. Yet the country’s premier cancer organization, the National Cancer Institute, does not include chemical cancer hazards in breast cancer information on its website.

Despite this extensive evidence, the NCI’s page on breast cancer prevention claims that “[s]tudies have not proven that being exposed to certain substances in the environment, such as chemicals, increases the risk of breast cancer.” This statement is misleading because it doesn’t convey that many chemicals likely increase breast cancer risk given that they do this in animals. It is unethical, and in many cases impossible, to study whether exposure to these chemicals cause cancer in humans, and evidence from animals is widely used as the basis for public health policies that limit chemicals in water, air, and food.

NCI is the de facto arbiter of what is considered valid cancer science in this country. Its website should reflect that. By not sharing the existing research on links between exposure to certain chemicals and breast cancer, it creates an information void that gives policymakers, health care providers, health advocates, cancer patients, and the public the impression that there is no problem.

This year alone in the U.S., an estimated 280,000 women and 2,600 men will be diagnosed with breast cancer, and more than 42,000 women and 500 men will die from it. The majority of these individuals have no inherited risk or family history of the disease. By ignoring the science on breast carcinogens, the NCI puts all women at risk, but especially women of color and low-income women, who are disproportionately exposed to toxic chemicals and pollution.

That is why we are taking the unprecedented step of breaking our silence and joining more than 100 individuals and organizations to publicly ask the NCI to take action. Both of us have been, and continue to be, strong supporters of the National Cancer Institute, but with thousands of lives at stake, we can no longer remain silent. As biomedical scientists and public servants, we’ve dedicated our careers to health science. One of us (L.B.) is a toxicologist who served as the director of the National Institute of Environmental Health Sciences (which is one of the National Institutes of Health) and the National Toxicology Program. The other (M.K.) is a cancer researcher who, through serving multiple terms on the President’s Cancer Panel, has come to understand the extent to which cancer risk is linked to environmental exposures.

We joined Breast Cancer Action and more than 100 leading scientists, cancer specialists, health and justice organizations, and breast cancer advocates in asking the NCI to share with the public information on chemical links to breast cancer. Drawing on our experience and expertise, we believe that sharing this research would reshape the national approach to prevention-oriented public health policy for breast cancer and beyond by acknowledging the importance of evidence from studies in animals and cells as a tool to identify chemical hazards and reduce exposure to them. This is only the start of efforts to get the NCI to make public this kind of information for all cancers.

Once the NCI publishes information on chemicals linked to breast cancer, we can begin to engage in an honest debate about what should be done to protect the public’s health. Information can save lives — and failing to disclose information will continue to put thousands at risk.

Linda S. Birnbaum is scholar in residence at Duke University and former director and scientist emerita of the National Institute of Environmental Health Sciences and the National Toxicology Program. Margaret L. Kripke is professor emerita at the University of Texas MD Anderson Cancer Center.