There is a growing trend of women choosing to have both of their breasts removed when they are diagnosed with breast cancer in one breast. The technical term for removing a breast without breast cancer is called a prophylactic mastectomy or risk reducing mastectomy . When a patient chooses to have their breast with cancer removed (mastectomy), if their other breast that does not have breast cancer is also removed it is called a contralateral prophylactic mastectomy (CPM). One study notes that the rate of CPM more than tripled between 1998 and 2012. (1)
There are several reasons behind this trend. Reconstruction following mastectomy has become readily available. For those choosing reconstruction, a desire for symmetry is an important driver of CPM.
Awareness of family history and genetic defects may lead others to choose CPM. These patients may elect to have a CPM to reduce their risk for developing future breast cancer. The “Angelina Jolie effect” occurred after she publicized her bilateral mastectomy in 2013, many women following her lead.
Experts from the American Society of Breast Surgeons (ASBrS) developed a consensus statement on CPM. They noted that women who are at average risk for developing breast cancer have a risk of developing a contralateral breast cancer of 0.1 to 0.6% a year. This is much lower than the expected risk of recurrence of most breast cancer patients, many of whom believe it will be inevitable that they will develop a second breast cancer.
And the ASBrS did not notice a survival benefit for average-risk women who underwent CPM. So women do not live longer if they choose to have both breasts removed. Those who carry a genetic defect that predisposes them to developing breast cancer are in a different group than average-risk women. Depending on the mutation, a primary reason why mutation carriers should consider risk reducing mastectomy of the other side should be to avoid the higher chance of a second cancer in that breast which is greater than 50% for mutation carriers.
Double the surgery, double the complications. CPM carries the risk of significant complications, including bleeding, infection, and skin loss. CPM extends the length of the operation, so anesthesia problems accordingly increase. (2)
For women who choose reconstruction, the reconstructed breast will not be identical to the natural breast. Many mastectomies will involve removal of the nipple. For those who have nipple sparing mastectomies (where the patient’s nipple is saved), there will be loss of nipple sensation and sexual function. CPM will cause loss of sensation to the skin, which often is permanent.
For patients whose breast reconstruction involves implants, there is usually a series of operations. The implants are often heavier than the natural breasts. Implants may need to be replaced from time to time. And rarely, implants may be associated with an unusual lymphoma (anaplastic large cell lymphoma). (3)
The American Board of Internal Medicine, through their Choosing Wisely campaign, advises women: “Don’t routinely perform a double mastectomy in patients who have a single breast with cancer.” (4)
The ASBrS did recommend CPM for high risk patients. These include BRCA genetic carriers, patients with a very significant family history of breast cancer and women who have had chest wall radiation prior to turning 30 (usually from Hodgkin’s lymphoma treatment). There are other good reasons that patients choose CPM as noted by ASBrS.
“The (ASBrS) consensus group agreed that CPM should be discouraged for an average-risk woman with unilateral breast cancer. However, patient’s values, goals and preferences should be included to optimize shared decision making when discussing CPM. The final decision whether or not to proceed with a CPM is a result of the balance between benefits and risks of CPM and patient preference.”
Wong SM, et al. Growing Use of Contralateral Prophylactic Mastectomy Despite no Improvement in Long-Term Survival for Invasive Breast Cancer. Ann Surg. 2016 Mar 8
Boughey J, et al. Contralateral Prophylactic Mastectomy (CPM) Consensus Statement from the American Society of Breast Surgeons: Data on CPM Outcomes and Risks. Annals of Surgical Oncology. 2016 Oct;23(10):3100-3105.
Gidengil CA, et al. Breast Implant-associated Anaplastic Large Cell Lymphoma: A Systemic Review. Plast Reconstr Surg. 2015 Mar;135(3):713-20.
- American Board of Medicine. Choosing Wisely. https://www.choosingwisely.org