03 Jan Risk of Breast Cancer in Women With Atypical Hyperplasia Better Defined
Medical Research: What is the background for this study? What are the main findings?
Dr. Hartmann: Women with atypical hyperplasia of the breast – which is defined via breast biopsy that was done to evaluate findings on a mammogram or a palpable concern – have been considered a “high risk” group of women, but the extent of their risk has not been clearly defined. As a consequence, practice guidelines for high-risk women (eg for screening MRI) do not include them. Mayo Clinic has developed a cohort of women with atypical hyperplasia who have been followed long-term for later breast cancers and we show that their risk of developing breast cancer is about 30% at 25 years of follow-up. This same level of risk was confirmed in the other large cohort of women with atypical hyperplasia, based at Vanderbilt University (Nashville Breast Cohort). This level of risk meets the current criterion for screening MRI and should also encourage the use of anti-estrogen drugs, such as tamoxifen, which have already been shown to be efficacious in this population of women.
Medical Research: What should clinicians and patients take away from your report?
Dr. Hartmann: There are about 100,000 US women each year diagnosed with atypical hyperplasia via breast biopsy. Although strictly speaking, atypical hyperplasia is a benign finding, it is associated with a sizable risk of a later breast cancer. Physicians from numerous disciplines care for women with high-risk benign breast issues, including gynecologists, family physicians, internists, surgeons and oncologists. These practitioners, and the patients themselves, need information about the absolute risk of breast cancer occurring over time after a diagnosis of atypical hyperplasia. This information is provided in the NEJM report. Also, current guidelines should be updated to include this high-risk population and specifics about their absolute risk, and that the risk level qualifies these patients for screening MRI.
Moreover, from the standpoint of risk reduction, four previously conducted breast cancer prevention trials included women with atypical hyperplasia. These trials used hormonal therapies (anti-estrogens) and showed that, in women with atypical hyperplasia, the use of such medications could lower the risk of a later breast cancer by 50% or more. Yet, other research has shown that women are quite reluctant to take such medications, primarily because of fear of side effects. In the NEJM report, we detail specific numbers of side effects that actually occurred in women who used these anti-estrogens (as opposed to the number of side effects seen in women taking placebo) and show that most of the side effects occurred quite uncommonly. Thus, we hope that the combination of information provided in this report on (i) actual risks of breast cancer and (ii) actual risks of side effects will help patients and practitioners make informed decisions on the best treatment approaches for women with atypical hyperplasia.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Hartmann: First, women with atypical hyperplasia should be included in future prospective trials of novel imaging strategies (they were not included in trials of MRI, which had been limited to women with hereditary risk).
Second, efforts should continue to predict which women with atypical hyperplasia are at highest risk, especially in the first 5-10 years after their biopsy, so they can be cared for optimally. Our research team, and others, continue to study the underlying molecular pathways that drive the progression from atypical hyperplasia to cancer; identifying such processes would not only aid in risk prediction but also identify driving pathways that could be blocked pharmaceutically.
Lynn C. Hartmann, Amy C. Degnim, Richard J. Santen, William D. Dupont, Karthik Ghosh. Atypical Hyperplasia of the Breast — Risk Assessment and Management Options. New England Journal of Medicine, 2015; 372 (1): 78 DOI: 10.1056/NEJMsr1407164