May 23, 2014
News Review From Harvard Medical School -- Study: Removing 2nd Breast Often Not Needed
Most women with breast cancer who also have the second breast removed don't really need to take that precaution, a new study finds. The study looked at information on 1,447 women treated for newly diagnosed cancer in a single breast. The women reported information to breast cancer registries for 3 to 5 years after treatment. Nearly 19% said they had strongly considered having both breasts removed. About 8% actually had double mastectomies. But researchers concluded that 69% of those who had both breasts removed actually had a low risk of developing cancer in the other breast. They did not have a strong family risk of cancer. They also did not have any gene mutations linked with increased risk of breast cancer. Women who had more detailed imaging of their breasts using MRI were more likely to have a double mastectomy. Researchers said MRI can often show spots that turn out to be nothing but do trigger worry. The journal JAMA Surgery published the study. HealthDay News wrote about it May 21.
By Mary Pickett, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Four months ago, I sat in a meeting with other doctors at my hospital. The name of this weekly conference was "Breast Cancer Tumor Board." Doctors from multiple specialties (including cancer specialists and primary care doctors like me) reviewed several patients with new breast cancer. I was at the meeting because one of my patients was planning treatment for breast cancer. It had been a surprise to find cancer on her mammogram. She is young, and she has no family history of cancer.
"This patient gives us a wonderful opportunity," the breast surgeon said after reviewing her small cancer on a mammogram. "Her cancer was caught early, and she is a perfect candidate for breast conserving surgery."
The surgeon described the small amount of tissue that he would need to remove along with her cancer. This procedure is called lumpectomy. She would have an excellent prognosis. The other doctors in the room were enthusiastic.
But my patient did not want breast-conserving surgery. She said that she feared getting a second cancer too much to keep her breasts. She asked for -- and she soon afterwards got -- a double (bilateral) mastectomy.
A review of 1,447 breast cancer patients was just published in the journal JAMA Surgery. This report tells us that among breast cancer patients, 19% of women strongly consider having both breasts removed. About 8% go on to have this procedure.
But most of these women are at remarkably low risk for breast cancer in their opposite breast. A family history of breast cancer can predict a higher breast cancer risk. So can having a specific BRCA gene mutation. But in this study, 69% of the women did not have either of those risk factors.
It is possible to get a second cancer, but breast cancer patients are commonly treated with medicines such as tamoxifen that reduce the risk. In fact, the chance that a woman with breast cancer will get a second cancer in her opposite breast is less than 5% in 8 years. This risk is lowered almost by half if a drug like tamoxifen is used. The risk for a second cancer in the opposite breast is about 14% in 25 years. These numbers are too low for a double mastectomy to increase survival.
Many women with newly diagnosed breast cancer request removal of both breasts even after receiving accurate information about their future risk. Breast MRI appears to contribute to fears. This imaging test shows a detailed view of breast tissue. It may reveal nodules that are of uncertain significance.
Are doctors advising women well enough during this highly emotional time? It is hard to say. Fears are real, and experience with cancer influences decision-making in a very personal way. For my patient, having both breasts removed was comforting. It made her feel liberated from her cancer. But ideally, we would be able to reassure women who have cancer without using unnecessary surgery.
What Changes Can I Make Now?
Two groups of women have a very high risk for a second breast cancer. For these women, having a double mastectomy could improve survival, compared with a single mastectomy or a lumpectomy:
- Women with a BRCA1 or BRCA2 mutation have a 65% to 85% lifetime risk of developing breast cancer. About 40% of women with a BRCA gene choose to have both breasts removed. Many also choose to have their ovaries removed because the gene can also promote ovarian cancer. Most women who have relatives with breast cancer do not carry these genes.
- A strong family history also increases risk. Breast cancer patients who have 2 first- or second-degree relatives with breast or ovarian cancer may benefit from having a bilateral mastectomy. First-degree relatives include parents, sisters and children. Second-degree relative include aunts, grandmothers and nieces. Other things that can signify high risk include a relative with cancer in both breasts, cancer in young relatives (less than 45 years old) or breast cancer in a male relative.
We have recently learned that extremely dense breast tissue may increase risk. This is something that can be seen on a mammogram. It can roughly double the risk for breast cancer. By itself, having extremely dense breasts is not a strong enough worry to make mastectomy advisable. But combined with a family history of cancer, it may add up to a serious risk.
If you have had a mastectomy on one side, you should have mammograms on the opposite breast every one to two years. Your doctor also should examine the side with cancer to check for cancer along the surgical scar.
What Can I Expect Looking to the Future?
Choosing to have surgery on both breasts to prevent breast cancer is difficult, courageous and quite personal. Take time with this decision. Talk with your family and your doctor. There is no need to decide quickly.
Having both breasts removed can reduce fears, but it creates its own psychological stress. In one study, 39% of women who had a risk-reducing mastectomy reported negative effects on their relationship with a spouse because of decreased sensation and changed body appearance.