Correspondence
Assessing the Risk of Breast Cancer
N Engl J Med 2000; 342:2002-2003June 29, 2000
- Article
To the Editor:
Armstrong et al. (Feb. 24 issue)1 discuss many of the potential benefits of using risk-prediction models to assess the risk of breast cancer for individual women and to guide care. However, there are also some risks associated with risk assessment that should be considered. For example, women identified as having a low risk according to risk-prediction models may be falsely reassured and then be less likely to pursue breast-cancer screening. It would be helpful to know how individual risk assessment affects women's decisions about screening.
There is also a need for accurate information about the risks and benefits of screening in women who are at high risk. These women may be more sensitive to ionizing radiation, particularly when screening is initiated at a younger age.2 Interpretation of mammograms is open to bias, and radiologists may be more likely to recommend further testing for women with high-risk histories, a practice that could lead to more false positive results.3 It would be helpful to know the extent to which mammography is more efficacious in women at high risk than in women at average risk. Unfortunately, there is little information on this topic.
3 ReferencesCaroline S. Rhoads, M.D.
Joann G. Elmore, M.D.
Harborview Medical Center, Seattle, WA 98104Suzanne Fletcher, M.D.
Harvard Pilgrim Health Care, Boston, MA 022151
Armstrong K, Eisen A, Weber B. Assessing the risk of breast cancer.N Engl J Med 2000;342:564-71.
2
Burke W ,Daly M ,Garber J , et al. Recommendations for follow-up care of individuals with an inherited predisposition to cancer. II. BRCA1 and BRCA2. JAMA 1997;277:997-1003
CrossRef | Web of Science | Medline3
Elmore JG ,Wells CK ,Howard DH ,Feinstein AR . The impact of clinical history on mammographic interpretations. JAMA 1997;277:49-52
CrossRef | Web of Science | Medline
To the Editor:
Armstrong et al. include a discussion of mammography in women 40 to 49 years of age but they do not mention that the density of the breast varies during the menstrual cycle, affecting both the sensitivity and the specificity of mammography. During the first week after menses, the breasts are the least dense and least tender.1
In addition, the ductal cells of the breast cycle with the menstrual period, and the percentage of ductal cells in the G2 phase is lowest during the first week after menses.2 Radiation can induce ductal cancer by striking the cells while they are in the G2 phase.3 The breasts are also least tender during the first week after the menstrual period. Thus, if mammograms are to be performed in women 40 to 49 years of age, the studies should be done during the first week after menstruation.
3 ReferencesJohn S. Spratt, M.D.
University of Louisville Health Sciences Center, Louisville, KY 40202-16711
White F ,Velentgas P ,Mandelson MT , et al. Variation in mammographic breast density by time in menstrual cycle among women aged 40-49 years. J Natl Cancer Inst 1998;90:906-910
CrossRef | Web of Science | Medline2
Meyer JS . Cell proliferation in normal human breast ducts, fibroadenomas, and other ductal hyperplasias measured by nuclear labeling with tritiated thymidine: effects of menstrual phase, age, and oral contraceptive hormones. Hum Pathol 1977;8:67-81
CrossRef | Web of Science | Medline3
Spratt JS . Re: Variation in mammographic breast density by time in menstrual cycle among women aged 40-49 years. J Natl Cancer Inst 1999;91:90-90
CrossRef | Web of Science | Medline
To the Editor:
By the end of this decade, about 0.4 percent of the population between the ages of 20 and 40 years will be survivors of childhood cancer.1 Many of these patients will have received ionizing radiation to the chest as part of their treatment. Women whose breasts were irradiated before the age of 18 have a much higher risk of carcinoma of the breast within the radiation field than age-matched controls. This has been demonstrated best in long-term survivors of Hodgkin's disease.2,3 Thus, survivors of childhood cancer should have been included as a recognized high-risk group in the review by Armstrong et al. Unfortunately, data-based guidelines for effective screening in this susceptible population are not available, although one group has suggested the use of screening mammography starting at the age of 25.4 Since most long-term survivors of childhood cancer do not continue to receive care in specialized clinics, it is vital that primary care practitioners become aware of this susceptible population of women.
4 ReferencesPhilip M. Rosoff, M.D.
Duke University Medical Center, Durham, NC 277101
Bleyer WA . The impact of childhood cancer on the United States and the world. CA Cancer J Clin 1990;40:355-367
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Bhatia S ,Robison LL ,Oberlin O , et al. Breast cancer and other second neoplasms after childhood Hodgkin's disease. N Engl J Med 1996;334:745-751
Full Text | Web of Science | Medline3
Hudson MM ,Poquette CA ,Lee J , et al. Increased mortality after successful treatment for Hodgkin's disease. J Clin Oncol 1998;16:3592-3600
Web of Science | Medline4
Kaste SC ,Hudson MM ,Jones DJ , et al. Breast masses in women treated for childhood cancer: incidence and screening guidelines. Cancer 1998;82:784-792
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Author/Editor Response
The authors reply:
To the Editor: We appreciate the comments of Rhoads and colleagues on the risks of assessment of breast-cancer risk. However, we believe that the benefits far outweigh any potential risks. Communicating the risk of breast cancer accurately to all women is important. We find that most women, and frequently their physicians, do not have an accurate perception of their risk of breast cancer. Women who misinterpret their risk, whether it is high or low, may be less likely to make good decisions about breast-cancer screening, breast-cancer prevention, and postmenopausal hormone-replacement therapy. We do not believe that telling women who are at low risk that they are at low risk represents a false reassurance. We strongly encourage adherence to age-appropriate recommendations for the use of screening mammography in all women, irrespective of risk. If women choose not to undergo screening, the fault lies in our inability to communicate accurately the benefits of this procedure, and not in risk assessment. In addition, women at high risk are likely to gain the greatest absolute benefit from mammography, with little if any documented risk. Routine screening should be encouraged for eligible women who are at high risk.
Spratt highlights the potential importance of the menstrual cycle in the timing of mammography among premenopausal women. The opportunity to screen young women early in the menstrual cycle, when their breasts are less dense than later in the cycle, is often missed. However, little is known about the mechanism of induction of DNA damage after breast irradiation, particularly the low-dose exposure used in mammography. Thus, we urge caution in extrapolating from the results of laboratory studies. We look forward to further work in this area.
Finally, we thank Rosoff for highlighting the importance of mantle irradiation as a risk factor for breast cancer. Young women treated for Hodgkin's disease in this way have a very high risk of breast cancer. These women certainly require intensive surveillance and further study.
Katrina Armstrong, M.D.
Andrea Eisen, M.D.
Barbara Weber, M.D.
University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6021
