The number of women who have a double mastectomy for breast cancer has tripled in the last 10 years, according to new research, even though this aggressive surgery has not been associated with a survival benefit.
Most women who are diagnosed with breast cancer undergo surgery as part of their treatment. There are three types: breast-conserving surgery, such as lumpectomy or partial mastectomy; unilateral mastectomy, which removes the entire breast affected by cancer; and double or bilateral mastectomy, which removes both the affected and unaffected breast.
In some cases, women opt to have breast cancer surgery even if they have not been diagnosed with breast cancer. Such was the case for Angelina Jolie, who announced in 2013 that she opted to have a double mastectomy.
In the study, researchers looked at the rates of the three types of surgery among nearly 400,000 women in a National Cancer Institute database who had been diagnosed with breast cancer and had surgery between 2002 and 2012.
The researchers found that the number of women who had bilateral mastectomy increased from 3.9% in 2002 to 12.7% in 2012, whereas the rate of unilateral mastectomy dropped from 35.8% to 28.9%. The rate of breast-conserving surgery held steady during that period of time at about 59%.
However, there is no reason, based on the current study or other studies, to think that bilateral mastectomy offers women any greater odds of survival. In the current study, researchers looked at the outcomes of more than 200,000 women in the database who had surgery prior to 2007. They estimated that the 10-year survival rates were similar for the three types of surgery: 91.8% for breast-conserving surgery, 83.8% for unilateral mastectomy and 90.3% for bilateral mastectomy.
"Despite all the data [over decades] comparing women who underwent breast-conserving surgery and mastectomy and the survival was exactly the same, the rate of bilateral mastectomy is actually picking up and not slowing down," said Dr. Mehra Golshan, distinguished chair in surgical oncology at Brigham and Women's Hospital. Golshan led the new research, which was published on Friday in Annals of Surgery.
Compared with breast-conserving surgery and unilateral mastectomy, bilateral mastectomy carries higher risk of complications associated with surgery, such as bleeding and infection, and can make recovery more difficult and cause women to lose feeling in their chests, Golshan said.
Nevertheless, it is possible that double mastectomy could be associated with a survival benefit in women who have a genetic risk factor for breast cancer, especially those who have a mutation in the BRCA genes, Golshan said. Although the researchers were not able to find out which women in the cohort had a BRCA mutation, they are probably too small a group to be responsible for the soaring rates of double mastectomy, he said.
Among women who have a BRCA mutation, even if they have not been diagnosed with breast cancer, such as Angelina Jolie, "it certainly makes sense to go the route of [double mastectomy]," Golshan said.
Even though Jolie's case was different than the women in the current study, it will probably only lead to further increases in the number of women who want to have a double mastectomy, either because they have a BRCA mutation or have been diagnosed with breast cancer, Golshan said. "I'm sure the numbers have continued to increase in the last two or three years," he said.
The reasons why women decide to have a double mastectomy instead of less extensive surgery following a breast cancer diagnosis are "very layered and complex," Golshan said.
One of the reasons is probably because of improvements in reconstructive surgery, Golshan said. Women may like the idea of having reconstructive surgery on both breasts because they think their breasts will look symmetric or better than if only one breast were removed. The current study found that rates of reconstruction increased both among women who had unilateral and bilateral mastectomy between 2002 and 2012.
Although better reconstruction techniques may have made the option of double mastectomy more appealing to women, "I think the No. 1 reason why women choose to have double mastectomy is fear of developing cancer in the opposite breast and fear of dying of breast cancer," said Dr. Todd M. Tuttle, chief of surgical oncology at the University of Minnesota, who was not involved in the current study.
In an earlier study, Tuttle and his colleagues found that the rates of double mastectomy among women who have surgery for breast cancer increased in the United States from 1.8% in 1998 to 4.5% in 2003.
Tuttle now advocates for doctors to try to discourage women who are interested in having double mastectomy as part of their breast cancer treatment.
"What I try to tell women and tell other doctors to tell women is that the risk of getting cancer [in the other breast] is low and removing it won't improve their survival and there are increased side effects of taking out your normal breast," Tuttle said.
The risk of developing cancer in the other breast is actually lower than ever, because of treatment advances, such as the use of tamoxifen and aromatase inhibitors, Golshan said. However, reductions in risk have not led to fewer women receiving double mastectomy, he added.
Nevertheless, it can be difficult for women to weigh all of this information in the little amount of time she may have to make a decision about surgery, Tuttle said. He tells women that they can always have surgery in the affected breast first and then think about whether they would like to have surgery to remove the other breast.
In the end, however, it is his patient's choice, Tuttle said.