• Preventive Surgery Reduces Cancer Risk in Women with BRCA1 or BRCA2 Mutations

    Among women with a BRCA1 or BRCA2 gene mutation, prophylactic mastectomy (preventive removal of the breasts) reduces the risk of getting breast cancer. Prophylactic salpingo-oophorectomy (preventive removal of the fallopian tubes and ovaries) reduces the risk of both breast and ovarian cancer. These results were published in the Journal of the American Medical Association.

    Inherited mutations in two genes—BRCA1 and BRCA2—have been found to greatly increase the lifetime risk of developing breast and ovarian cancer. Mutations in these genes can be passed down through either the mother’s or the father’s side of the family.

    Women with a BRCA mutation have a 54% to 86% lifetime risk of developing breast cancer. Risk of ovarian cancer ranges from 36% to 63% among women with a BRCA1 mutation, and from 10% to 27% among women with a BRCA2 mutation.

    Options to manage this increased cancer risk include regular cancer screening, chemoprevention (use of medications to reduce risk), or preventive surgery (surgery before cancer is diagnosed).

    Preventive surgery may involve removal of the breasts (prophylactic mastectomy) and/or removal of the ovaries and fallopian tubes (prophylactic salpingo-oophorectomy). Because available screening tests do not appear to reduce ovarian cancer mortality, prophylactic salpingo-oophorectomy is often recommended for BRCA1 and BRCA2 carriers who have completed childbearing.

    To explore the effectiveness of prophylactic mastectomy and prophylactic salpingo-oophorectomy, researchers collected information about 2,482 women with a BRCA1 or BRCA2 mutation. The study was conducted at 22 centers in Europe and North America.

    • During roughly three years of follow-up, there were no breast cancer diagnoses among the 247 women who underwent prophylactic mastectomy. By comparison, among women who did not undergo prophylactic mastectomy, 7% (98 out of 1372) were diagnosed with breast cancer over a similar follow-up period.
    • Risk of ovarian cancer was 1%-2% among women who underwent prophylactic salpingo-oophorectomy, compared with 6% among women who did not undergo prophylactic salpingo-oophorectomy.
    • Among women with a BRCA1 mutation and no prior breast cancer, risk of breast cancer was 14% among women who underwent prophylactic salpingo-oophorectomy, and 20% among women who did not undergo prophylactic salpingo-oophorectomy.
    • Among women with a BRCA2 mutation and no prior breast cancer, risk of breast cancer was 7% among women who underwent prophylactic salpingo-oophorectomy, and 23% among women who did not undergo prophylactic salpingo-oophorectomy.
    • Three percent of women who underwent prophylactic salpingo-oophorectomy died of any cause during follow-up, compared with 10% of women who did not undergo prophylactic salpingo-oophorectomy. Prophylactic salpingo-oophorectomy also reduced the likelihood of dying from breast or ovarian cancer.

    The results provide additional evidence that prophylactic mastectomy and prophylactic salpingo-oophorectomy reduce the risk of breast and ovarian cancer among women with a BRCA1 or BRCA2 mutation. Prophylactic salpingo-oophorectomy also reduced overall mortality.

    The information provided by this study may help women with a BRCA1 or BRCA2 mutation make a more informed decision about prophylactic surgery. Women are advised to talk with their doctor about the options available for preventing breast and ovarian cancer or for detecting these cancers at an early stage.

    Reference: Domchek SM, Friebel TM, Singer CF et al. Association of risk-reducing surgery in BRCA1 or BRCA2 mutation carriers with cancer risk and mortality. JAMA. 2010;304:967-975.