DEAR MAYO CLINIC: I recently was diagnosed with early stage breast cancer in one breast. I’m planning to have a mastectomy and breast reconstruction. What are the chances I’ll get cancer in my other breast? I’m trying to decide if I should go ahead with a double mastectomy now. I don’t really want to, but I don’t want to go through this whole process twice, either.
ANSWER: In general, for someone in your situation the risk of developing a new cancer in the other breast is typically quite low. Removing the normal breast is not required as part of the treatment for your breast cancer. The decision to have a mastectomy on the cancer side and also remove a breast that does not have cancer (the other side) is a very personal one. There are valid reasons some women choose to pursue this surgery. But it will have a long-term effect on your body, so you need to be comfortable with the decision you make.
A mastectomy is surgery that involves removing the majority of breast tissue from a breast as a way to treat or prevent cancer. For cancer prevention, this surgery reduces the risk of developing breast cancer by about 90 to 95 percent. It is not 100 percent because some areas of breast tissue do remain after a mastectomy. Those areas of tissue could develop breast cancer, although the chances of that happening are very small.
When you have a mastectomy to treat cancer in one breast, you could have the breast that does not have cancer removed at the same time. Some women opt to do this because they are anxious about developing cancer in the other breast. But you can also keep the normal breast. Research shows that this decision does not have an impact on overall survival.
Current medical evidence indicates the risk of developing a cancer in the other breast to be reasonably low at about half a percent a year. For women who have hormone therapy after a mastectomy because their tumors are hormone receptor positive, this risk is reduced by about 50 percent.
Certain factors can make a difference in your risk, though. If you have a strong family history of breast cancer or if you have tested positive for a mutation in one of the breast cancer genes, then the chances you will develop cancer in your other breast are significantly higher. Before you make a decision about having a double mastectomy, carefully review your personal risk of breast cancer with your doctor.
If you do not have other factors that raise your risk, there are additional questions to consider. First, if you do have a double mastectomy, are you comfortable with the risks of a more complex and longer operation? Having both breasts removed, rather than just one, increases the possibility of surgical complications such as bleeding and infection.
Second, if you do not have a double mastectomy, are you willing to participate in ongoing monitoring for cancer in your other breast? If you do not have both breasts removed, you will still need regular mammograms once a year on the breast that remains.
Third, how important is it to you that your breasts look similar? If you have one breast reconstructed after a mastectomy, it is unlikely that your remaining breast will match its appearance without some type of cosmetic surgery on the natural breast.
Talk with your doctor about these topics, along with any other concerns or questions you may have. Also, discuss what will happen before, during and after surgery, so you can set your expectations accordingly. Choosing to have a double mastectomy is a big decision. Make sure you are well informed about all the possible benefits and drawbacks for your situation before you move forward. — Judy C. Boughey, M.D., Surgery, Mayo Clinic, Rochester, Minn.