June 8, 2021

Delivered via email. Also available in PDF format


Dr. Norman E. Sharpless
Director, National Cancer Institute
9609 Medical Center Drive Rockville, MD 20850


Dr. Francis Collins
Director, National Institute of Health
10 Center Drive, Bethesda, MD 20892

Xavier Becerra

Secretary, Health and Human Services

200 Independence Avenue, S.W. Washington, D.C. 20201


Dear Dr. Sharpless,

This letter provides comment on the National Cancer Institute’s (NCI) revisions to the Breast Cancer Prevention Patient and Provider Physician Data Queries (PDQs) made on January 8, 2021, following our recommendations to the agency to include better, more accurate information about environmental exposures specific to cancer-causing chemicals. We appreciate the agency taking action to address our initial concern that the patient and health professional PDQs significantly underrepresented the importance of reducing breast cancer risk related to environmental exposures.1 However, the revised updates reveal the agency’s renewed commitment to withholding information on the growing body of evidence regarding the potential links between chemical exposure and breast cancer, further harming those at risk of the disease.

The agency’s lack of accountability and transparency has led to a failure to produce and disseminate the most up-to-date and effective information about the environmental impacts on breast cancer. This not only affects the ability of individuals and healthcare providers to identify health protective measures, but also impedes important national efforts to create systemic change that supports breast cancer prevention. The undersigned organizations and individuals are discontented with the NCI’s tepid attempt to address environmental impacts on breast cancer.

As the nation’s leading cancer agency, we expect the NCI to adopt the precautionary principle as the gold standard of prevention. The recent revision to the Breast Cancer Prevention Patient and Provider PDQs continues to dismiss the evidence about environmental chemicals. The revisions highlight limitations in research methods without describing what we do know and offering a sensible framework for evaluating the evidence to protect health.

For instance, the revised Breast Cancer Prevention Patient PDQ states, “Even if a chemical is shown in a laboratory test to cause cancer, this does not necessarily mean it will cause cancer in people exposed to that chemical in the environment.” However, it fails to note that many chemicals that cause cancer in animals do cause cancer in people. The outcomes in animal results are an important and widely accepted red flag signifying the need for further investigation, not dismissal. Currently, all chemicals that cause cancer in humans have also been shown to cause cancer in animal studies, and animal studies remain the best method for identifying potential human carcinogens in order to make rational decisions about exposures.

Another concern in the Patient PDQ is the addition of “individual chemicals are likely to cause only a small increase in risk.” This blatantly minimizes risks that may be relatively small for an individual and does not take into consideration the cumulative impact of ongoing exposures. When exposures are ubiquitous, small increments in individual risk represent large public health risks that will cause health harms for many people.

A similar mindset undermines the Health Professional PDQ as a resource for clinicians to have meaningful conversations with patients. References to the Institute of Medicine (IOM) and Interagency Breast Cancer and Environmental Coordinating Committee (IBCERCC) reports are appreciated. However, the PDQ statement that these panels found the evidence to be inconclusive is incomplete and misleading without also stating that the IOM report recommends prudent actions to reduce exposure to chemicals with biological evidence of links to breast cancer. In addition, the IBCERCC report is focused on research gaps and not on translational recommendations. However, it does recommend integrating animal as well as human evidence about environmental chemicals. Most people don’t want to wait for “definitive evidence” or proof of harm before acting to reduce and eliminate practices that we suspect do harm to human health.

In short, the revision doubles down on a bad approach that fails to acknowledge the evidence that certain environmental chemicals increase the risk of breast cancer. There is an urgent need for fundamental change in how we understand breast cancer prevention. As opposed to uplifting the importance of reducing breast cancer risk related to environmental exposures, the revisions of both PDQs defend a bad approach and leave us to wonder about the agency’s rationale for undermining the science. The revisions provided not only fail to provide industry-leading information to individuals and providers, the lax approach to chemical exposures also greenlights industry polluters to continue to produce these relevant chemical exposures in the first place. Given the evidence that links certain pesticides, air pollutants, workplace exposures, and consumer product chemicals to breast cancer, people deserve better information from NCI to inform their personal decisions and facilitate policy discussions from the local to national level.

If the NCI is going to untangle the complex intersection of environmental exposures and risk for breast cancer, we encourage you to review our original request supported by over 100+ signatories, and to meet with a selected group of signatories of this letter to develop an action plan for implementing solutions to address our concerns by Friday, June 11th.

We look forward to supporting the agency as it takes immediate action to update the patient and provider PDQs in the most accurate way. Further communication on this important matter can be directed to Dr. Krystal Redman, Executive Director at Breast Cancer Action and Jayla Burton, MPH, MS Program Manager at Breast Cancer Action.



1. Breast Cancer Action

2. Silent Spring

3. Environmental & Public Health Consulting

4. Alaska Community Action on Toxics

5. Zero Breast Cancer

6. Women’s Voices of the Earth

7. Clearya

8. Concerned Health Professionals of New York

9. Worksafe

10. Fight For Zero

11. Toxic Free NC

12. Breast Cancer Prevention Partners

13. Project Coffeehouse

14. Friends of the Earth

15. DES Action USA

16. Sierra Club

17. San Francisco Bay Physicians for Social Responsibility

18. Center on Race, Poverty and the Environment

19. Latinas Contra Cancer

20. Black Women for Wellness

21. Our Bodies Ourselves

22. The Center for Black Health & Equity

23. Alliance of Nurses for Healthy Environments

24. Children’s Environmental Health Network

25. Social Science Environmental Health Research Institute

26. Dr. Yolanda Whyte Pediatrics

27. Breast Implant Safety Alliance

28. WomenCARE

29. The Oliver Foundation

30. Center for Biological Diversity

31. TOUCH, The Black Breast Cancer Alliance

32. National LGBTQ Network


1. Linda S. Birnbaum, PhD, DABT, ATS; Scientist Emeritus, NIEHS/NTP and Scholar-in-Residence, Duke University*

2. Karuna Jagger, MA; former Executive Director, Breast Cancer Action*

3. Marj Plumb, DrPH; Community-based breast cancer research consultant, Omaha, NE*

4. Krystal Redman, DrPH; Executive Director, Breast Cancer Action*

5. Jayla Burton, MPH, MS; Program Manager, Breast Cancer Action*

6. Janet Gray, PhD; Professor Emerita, Vassar College*

7. Eve Shapiro, MD; Physicians for Social Responsibility

8. Iona Cheng, PhD, MPH; Professor, University of California, San Francisco*

9. Catherine DeLorey, RN, DrPH; President, Women’s Health Institute*

10. Heather Sarantis, MS; Environmental Health Consultant*

11. Ruthann Rudel; Research Director, Silent Spring Institute*

12. Carol F. Kwiatkowski, PhD; Senior Science and Policy Associate, Green Science Policy Institute

13. Laura N. Vandenberg, PhD; Associate Professor, University of Massachusetts, Amherst*

14. Lauren C. Heberle, PhD; Associate Professor and Director, Center for Environmental Policy and Management, University of Louisville*

15. Adrian A. Franke, PhD; Professor, University of Hawaii*

16. Kathryn Rodgers, MPH; Staff Scientist, Silent Spring Institute*

17. Julia Brody, PhD; Executive Director and Senior Scientist, Silent Spring Institute*

18. Margaret L Kripke, PhD; Professor Emerita at MD Anderson Cancer Center and former member of the President’s Cancer Panel*

19. Sora Park Tanjasiri, DrPH, MPH; Professor, University of California, Irvine*

20. Kathy Attar, MPH; Program Manager, Children’s Environmental Health Network*

21. Barbara A. Cohn, MCP MPH PhD; Director and Senior Research Scientist, Child Health and Development Studies, Public Health Institute*

22. Lauren C. Heberle, PhD; Associate Professor and Director, Center for Environmental Policy and Management, University of Louisville*

23. Marion H. E. Kavanaugh-Lynch, MD, MPH; Director, California Breast Cancer Research Program*

24. Ngina Lythcott, RN, MSW, DrPH; Intercultural Cancer Council (ICC)*

25. Richard Clapp, DSc, MPH; Professor Emeritus, Lowell Center for Sustainable Production*

26. Robert A. Hiatt, MD, PhD; Professor of Epidemiology & Biostatistics, Associate Director for Population Sciences, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco*

27. Sarah Gehlert, MA, MSW, PhD; Dean and Professor, School of Social Work, The University of Southern California*

28. Scarlett Lin Gomez, MPH, PhD; Professor, Department of Epidemiology and Biostatistics, University of California, San Francisco*

29. Julie Morgan, RN; Former Board, Breast Cancer Action*

30. Tracy Kolian, MPH; Board, Breast Cancer Action*

31. Gail Kaufman; Board, Breast Cancer Action*

32. Alicia Justice, MPH; Board, Breast Cancer Action*

33. Lee Ann Slinkard; Board, Breast Cancer Action Board*