Patients at increased risk of breast cancer have a range of treatment options available to decrease their risk of breast cancer development. The absolute risk reduction by any of these strategies is dependent on the individual woman's actual risk of breast cancer development. Statistical models for risk stratification, as well as the availability of genetic testing, enable women and their physicians to evaluate the risk of breast cancer. A number of risk-reducing treatment options exist for these women, and they vary in efficacy. Options include frequent surveillance with clinical examination and imaging, chemoprevention, prophylactic salpingo- oophorectomy (PSO), and prophylactic mastectomy (PM). The individuals most likely to benefit from bilateral PM are those with the highest risk—BRCA carriers and those with a strong family history of breast cancer. Women with a personal history of breast cancer are also at higher risk for a second primary breast cancer in the contralateral breast and may choose to pursue contralateral prophylactic mastectomy (CPM) to decrease this risk as well as for cosmetic and psychological reasons. As a preventive measure PM remains controversial. There are no randomized controlled trials (and likely will not be in the future) to substantiate the potential benefit or harm associated with PM. Since PM is an irreversible procedure, providers and patients must understand its consequences, benefits, limitations, and available alternatives. This chapter discusses which patients may consider prophylactic surgery and summarizes data on the efficacy of PM for the prevention of breast cancer and its effect on survival.
No Prior History of Breast Cancer
The absolute risk reduction afforded by PM is greatest in the women at highest risk of breast cancer development. The average lifetime risk of breast cancer for women in the United States is 12.7% with a lifespan of 85 years. This risk is greatest after the sixth decade of life.1 Most women, however, tend to overestimate their risk of breast cancer.2 It is important that women have realistic risk estimates in order to help them make informed decisions regarding risk reduction. For women without a personal or family history of breast cancer, the Gail model is the most commonly used tool to predict risk of breast cancer in women, and is viewed 20,000 to 30,000 times per month.3 The Gail model is accurate for predicting breast cancer incidence in populations of women; however, its major limitation in terms of clinical use is its poor accuracy when used for risk prediction in individuals.4 Also, the Gail model does not apply to women with a history of lobular carcinoma in situ (LCIS) or ductal carcinoma in situ (DCIS) and has been shown to underpredict risk for women with atypical hyperplasia.5
Factors associated with a generalized increased risk of breast cancer above the population average include LCIS, atypical hyperplasia, and increased breast density. Atypical ductal or lobular hyperplasia found at breast biopsy (preferably confirmed by a breast pathologist) is associated ...