Prophylactic or optional mastectomies

Diana Zuckerman, PhD, and Brandel France de Bravo, MPH

Every year, thousands of women choose to undergo a mastectomy (surgery to remove the breast tissue) when lumpectomy (removal of only a small part of the breast) would be an equally effective option for them. Some women choose a bilateral mastectomy (removal of both breasts, also called a double mastectomy) when there is cancer in only one breast. Even women who do not have breast cancer may undergo mastectomies as a preventive measure because of their high risk of breast cancer, as was the situation with Angelina Jolie. If either one or two breasts without cancer are removed, the surgery is called a “prophylactic mastectomy.”

Helping patients make an informed decision about whether to have a mastectomy is an important aspect of the physician-patient relationship. Unfortunately, many patients are not able to get the information they need from their physicians. A patient who is seriously considering a mastectomy or bilateral mastectomy that is not medically necessary may be basing her decision more on fear than on information. They may benefit from unbiased information, counseling, or from a second opinion before making a final decision.

The purpose of this article is to provide information that patients and family members can use to help them discuss their options with their physicians.

Should I remove one breast or both?

 Women in the U.S. who are diagnosed with early-stage breast cancer sometimes remove both breasts even if only one has cancer.  However, new research indicates that having a healthy breast removed in addition to the breast with cancer increases the chances of medical complications.  Even though removing a healthy breast lowers the risk of getting cancer in that breast in the future, the risk of cancer in that healthy breast was already less than 1% per year unless the woman has a BRCA gene or some other very high risk factor.¹ Hormone pills such as tamoxifen or aromatase inhibitors can further reduce that already low risk. In a study of more than 4,000 women, removing the healthy breast (“contralateral breast”) doubled the chances of having wound complications in the first month after surgery: from about 3% for women who had only the breast with cancer removed to about 6% for women who also had the healthy breast removed. About 4% of women who had a single mastectomy experienced some kind of complication (not necessarily wound-related) in the 30 days after surgery, compared to 8% of women who had both breasts removed. Dr. Fahima Osman of the University of Toronto presented these findings at the 2013 meeting of the American Society of Breast Surgeons.²

What if I have a breast cancer gene (BRCA1 and BRCA2)?

Women with known mutations in the BRCA1 and BRCA2 genes have a lifetime risk of breast cancer ranging from 40% to 65% on average, compared to 12% for women in the general population. Women with BRCA1 or BRCA2 mutations often develop breast cancer before age 50 and have a high risk of bilateral breast cancer and ovarian cancer.³ Removing breasts with no sign of cancer is called a prophylactic (preventive) mastectomy. Prophylactic mastectomy and prophylactic oophorectomy (removal of the ovaries) have both been shown to greatly reduce – but not eliminate – the risk of breast cancer in BRCA mutation carriers.³  Among women with strong family histories of breast cancer, individuals of Ashkenazi Jewish descent have an 8 times greater frequency of carrying these mutations in BRCA1 or BRCA2 compared with other women.⁴

Lumpectomy with radiation therapy is just as effective for preventing same-breast tumor recurrence in breast cancer patients with BRCA mutations as it is for other women. Questions remain, however, about how other adjuvant treatments (such as chemotherapy) affect survival of women with these gene mutations.⁴

For women with the BRCA1 or BRCA2 genes, it is important to remember that the risk of breast cancer in the next 5 or 10 years is much lower than the lifetime risk of breast cancer. For example, the risk of breast cancer in her 20s is very low, even with BRCA1 (less than 3%) or BRCA2 (approximately 1%). For a 30-year old woman, the risk by age 39 is higher (10% for women with BRCA1 and 8% for BRCA2). For a 40-year-old woman, the risk by age 49 is 16% for women with BRCA1 and 13% for women with BRCA2.⁴ Although these 10-year risk levels are much higher than for most women, they are much lower than the life-time risk that is so frightening. It is also important to remember that cancer treatments and prevention strategies are improving, so the risks of cancer may decrease and the survival rates are improving.

Is there something I can do other than Prophylactic Mastectomies?

Prophylactic mastectomies can prevent breast cancer, but many women who undergo prophylactic mastectomies would never have developed breast cancer, even without the surgery.  To make an informed decision about whether to undergo a prophylactic mastectomy, women need a clear understanding of the risks and benefits as well as other strategies that also reduce risk.

Tamoxifen and raloxifene have both been shown to reduce the risk of breast cancer for women who have not had cancer but are at greater risk. These drugs can also reduce the risk of breast cancer for women with BRCA1 or BRCA2 mutations.

For women at high risk of breast cancer for any reason, routine screening starting at a young age can be an alternative to prophylactic mastectomy. Options include clinical breast exams, mammograms, ultrasounds, and MRIs. MRIs are much more accurate than mammograms for young women and women with dense breast tissue, and avoid the additional risks associated with radiation — risks that should be avoided by women who already are susceptible to breast cancer. A 2012 study of women with BRCA1/2 mutations who were under 30 years old showed that the increased radiation they were exposed to from early, frequent mammograms increased their risk of breast cancer. Women with the most radiation exposure had the highest risk of breast cancer, compared to other women with the same gene mutations.⁵ Those risks can be avoided by replacing early mammograms with MRIs instead. However, it is important to note that MRIs used for screening tend to result in overtreatment, including unnecessary biopsies and mastectomies.⁶

Research indicates that a low-fat diet, weight control, and exercise may reduce the risk of breast cancer for all women, including women at high risk and women who previously were treated for breast cancer.⁷⁸