By Breast Cancer Fund Director of Science Sharima Rasanayagam, Ph.D.
A new study, published in JAMA Oncology, found that aggressive treatments (surgery followed by radiation therapy) of ductal carcinoma in situ, or DCIS, did not lead to a reduction in death. While the study sparks questions about how DCIS should be classified and treated, it also underlines the importance of primary prevention.
DCIS is a condition where abnormal cells are found on the lining of the breast milk ducts, but have not spread outside of the ducts to surrounding tissue. It is often referred to as Stage 0 cancer. The question is whether or not the condition should be identified and treated as cancer, pre-cancer or a risk factor. Surgery and radiation may be considered over treatment if it is a risk factor.
In the study, researchers analyzed data from 100,000 women diagnosed with DCIS. One key insight that emerged from the 20-year analysis, was that aggressive treatment (radiation therapy after lumpectomy) of most DCIS does not lead to a reduction in breast cancer mortality. Worse, there may be a slight increase in mortality with radiation therapy, especially if the disease is on the left side, according to an editorial published in JAMA by Dr. Laura Esserman of UCSF. The study did find aggressive treatments to be effective for women under 40 and African American women, but for others the experts disagree on the best way forward after a DCIS diagnosis. While some medical experts, including the authors of the study, conclude that DCIS should no longer be treated with surgery and radiation, others, such as the chief breast cancer surgeon at Memorial Sloan Kettering Cancer Center, argue in a New York Times article, that DCIS should continue to be treated the way it is now.
In spite of the dissonance, most people can agree that investment in primary prevention of this disease needs to be part of the conversation. If, for many women, a DCIS diagnosis does not mean they have breast cancer now, but may be at increased risk for developing the disease in the future, it may be an opportunity to proactively reduce environmental risks through diet, exercise and by avoiding toxic chemicals linked to breast cancer in their homes and workplaces. There are now thousands of scientific studies affirming the link between breast cancer and toxic exposures in our everyday lives. For example Teflon in pots and pans, endocrine-disrupting chemicals in our personal care products and pesticides in our food, could be increasing our breast cancer risk. While we know that there are actions each of us can take every day to reduce these risks, we also know that individual action is not enough and the federal laws that govern toxic chemicals need to be updated to protect all of us. Only then can we begin to change the odds so that far fewer people will have to grapple with this disease.
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As the director of science, Sharima oversees the Breast Cancer Fund’s science-related activities, including monitoring and interpreting emerging research, and developing and managing science-related program and policy initiatives. She also serves on the advisory committee of the California Breast Cancer Research Program, the largest state-funded breast cancer research effort. Sharima holds a Ph.D. in microbiology from the University of Kent at Canterbury, U.K.