Some women who've been diagnosed with early-stage breast cancer in one breast choose to have that breast and the other healthy breast removed. Removing the other healthy breast is called contralateral prophylactic mastectomy.
The healthy breast typically is removed because of understandable fear that a new, second breast cancer might develop in that breast. Some doctors are concerned that too many women are choosing the very aggressive step of contralateral prophylactic mastectomy during or shortly after breast cancer surgery because they overestimate their risk of future breast cancer.
A very small study found that women considering contralateral prophylactic mastectomy overestimated their risk of developing breast cancer in the healthy breast. Once the women took time to carefully consider their actual risk of developing a new breast cancer, they usually decided against removing the healthy breast. These results were presented at the 2010 European Breast Cancer Symposium.
The study involved 27 women diagnosed with early-stage breast cancer who wanted to have the healthy breast removed at the same time or shortly after breast cancer surgery. All the women believed their risk of developing a new, second breast cancer in the healthy breast was very high. Also, none of the women thought they would be alive 5 years after diagnosis.
All the women agreed to wait 1 year to make their decision about contralateral prophylactic mastectomy. During the 1-year waiting period, the women were given detailed information on their individual risk of developing a new cancer in the healthy breast. After the waiting period, only four women decided to have contralateral prophylactic mastectomy.
When you're first diagnosed with breast cancer, fears about the future can affect how you make decisions. It's understandable that many women would want to eliminate any risk of another breast cancer developing in the healthy breast by choosing contralateral prophylactic mastectomy. Still, the actual risk of a new breast cancer developing in the healthy breast is likely to be much lower than many women estimate. Especially if they're making risk estimates when breast cancer is first diagnosed and treated.
A 2009 study on contralateral prophylactic mastectomy found that that a small group of women with a specific breast cancer risk profile or who had been diagnosed with breast cancer with certain characteristics got the most benefits from prophylactic mastectomy. The women who got the most benefits had any of three factors:
- A Breast Cancer Risk Assessment Tool score (also called a Gail score) of more than 1.67% risk. The Gail score is based on a series of specific personal health questions that women and their doctors answer together. The score estimates the risk of a woman developing invasive breast cancer in the next 5 years.
- A pathology report that showed invasive lobular breast cancer (ILC), which is less common than invasive ductal breast cancer (IDC).
- Breast cancer in more than one location in the breast.
Women with any one of these three factors were more than 3 times more likely than women who did not have any of these factors to develop breast cancer in the opposite breast. Prophylactic mastectomy may make the most sense for women with any one of these three factors.
Based on this study, most women considering contralateral prophylactic mastectomy might want to wait to make a final decision. With their doctors, they can learn more about their unique situations and their actual risk of developing a new cancer in the opposite breast and explore all of their options to reduce that risk.
If you've been diagnosed with early-stage breast cancer, ask your doctor about ALL of your treatment and risk reduction options. Contralateral prophylactic mastectomy is only one of these options and is a very aggressive step. While that may be the right decision for you, give yourself the time you need to consider your decision carefully. Talk to your doctor to make sure that your decisions are based on your actual risk. Talk about your Gail score and how the cancer details in your pathology report may affect your future risk. Together, you and your doctor can make the decisions that are best for you and your unique situation.
The National Cancer Institute's Gail score page has more information about the tool.