In a striking trend, the rate of contralateral prophylactic mastectomy (CPM) has risen by 30% over the last 10 years in the United States.1 Many women undergo CPM because of the fear and anxiety of cancer recurrence and their perceived risk of contralateral breast cancer; however, few women have a medical condition that necessitates removal of the contralateral breast. The medical indications for CPM include having a pathogenic genetic mutation (eg, BRCA1 and BRCA2), a strong family history of breast cancer, or prior mediastina chest radiation.
The actual risk of contralateral breast cancer is much lower than perceived. In women without a genetic mutation, the 10-year risk of contralateral breast cancer is only 3% to 5%.1 Also, CPM does not prevent the development of metastatic disease and offers no survival benefit over breast conservation or unilateral mastectomy.2 Furthermore, compared with unilateral therapeutic mastectomy, the “upgrade” to a CPM carries a 2.7-fold risk of a major surgical complication.3 It is therefore important that patients receive appropriate counseling regarding CPM, and that this counseling include cancer stage at diagnosis, family history and genetic risk, and cancer versus surgical risk (see “Counseling patients on contralateral prophylactic mastectomy” for key points to cover in patient discussions).
Counseling patients on contralateral prophylactic mastectomy
Commonly, patients diagnosed with breast cancer consider having their contralateral healthy breast removed as part of a bilateral mastectomy. They often experience severe anxiety about the cancer coming back and believe that removing both breasts will enable them to live longer. Keep the following key facts in mind when discussing treatment options with breast cancer patients.
Cancer stage at diagnosis. How long a patient lives from the time of her breast cancer diagnosis depends on the stage of the cancer at diagnosis, not the type of surgery performed. A woman with early stage I or stage II breast cancer has an 80% to 90% chance of being cancer free in 5 years.1 The chance of cancer recurring in the bones, liver, or lungs (metastatic breast cancer) will not be changed by removing the healthy breast. The risk of metastatic recurrence can be reduced, however, with chemotherapy and/or with hormone-blocker therapy.
Family history and genetic risk. Few women have a strong family history of breast and/or ovarian and other cancers, and this issue should be addressed with genetic counseling and testing prior to surgery. Those who carry a cancer-causing gene, such as BRCA1 or BRCA2, are at increased risk (40% to 60%) for a second or third breast cancer, especially if they are diagnosed at a young age (<50 years).2,3 In women who have a genetic mutation, removing both breasts and sometimes the ovaries can prevent development of another breast cancer. But this will not prevent spread of the cancer that is already present. Only chemotherapy and hormone blockers can prevent the spread of cancer.
Cancer risk versus surgical risk. For women with no family history of breast cancer, no genetic mutation, and no prior chest wall radiation, the risk of developing a new breast cancer in their other breast is only 3% to 5% every 10 years.3,4 This means that they have a 95% chance of not developing a new breast cancer in their healthy breast. Notably, removing the healthy breast can double the risk of postsurgical complications, including bleeding, infection, and loss of tissue and implant. The mastectomy site will be numb and the skin and nipple areola will not have any function other than cosmetic. Finally, wound complications from surgery could delay the start of important cancer treatment, such as chemotherapy or radiation.
The bottom line. Unless a woman has a strong family history of breast cancer, is diagnosed at a very young age, or has a genetic cancer-causing mutation, removing the contralateral healthy breast is not medically necessary and is not routinely recommended.
- Hennigs A, Riedel F, Gondos A, et al. Prognosis of breast cancer molecular subtypes in routine clinical care: a large prospective cohort study. BMC Cancer. 2016;16(1):734.
- Graeser MK, Engel C, Rhiem K, et al. Contralateral breast cancer risk in BRCA1 and BRCA2 mutation carriers. J Clin Oncol. 2009;27(35):5887–5992.
- Curtis RE, Ron E, Hankey BF, Hoover RN. New malignancies following breast cancer. In: Curtis RE, Freedman DM, Ron E, et al, eds. New Malignancies Among Cancer Survivors: SEER Cancer Registries, 1973-2000. Bethesda, MD: National Cancer Institute. NIH Publ. No. 05-5302. 2006:181–205. http://seer.cancer.gov/archive/publications/mpmono. Accessed September 18, 2016.
- Nichols HB, Berrington de Gonzalez A, Lacey JV Jr, Rosenberg PS, Anderson WF. Declining incidence of contralateral breast cancer in the United States from 1975 to 2006. J Clin Oncol. 2011;29(12):1564–1569.
Women should be made aware that there are alternatives to mastectomy that have similar, or even better, outcomes with improved quality of life. Furthermore, a multi‑disciplinary, team-oriented approach with emphasis on minimally invasive biopsy and better cosmetic outcomes has enhanced quality of care. Knowledge of this team approach and of modern breast cancer treatments is essential for general ObGyns as this understanding improves the overall care and guidance—specifically regarding referral to expert, high-volume breast surgeons—provided to those women most in need.