It used to be that doctors made treatment decisions on behalf of patients, often leaving them feeling helpless in determining their own care. Now in certain situations that sense of helplessness may be replaced by confusion, as patients are asked to make their own choices about a course of treatment. Emotional factors can play a big role in those decisions — and may sometimes outweigh scientific evidence.
Treatment for early-stage breast cancer is a case in point. Since the late 1970s, women diagnosed with early-stage tumors have had a choice of which course to pursue: removal of the tumor and a small portion of the surrounding breast tissue (lumpectomy) followed by radiation therapy, or removal of the entire breast (mastectomy).
Women concerned about developing a second cancer may also elect to have their other, healthy breast removed, a procedure called contralateral prophylactic mastectomy (CPM). Increasingly, many women are choosing this more-extensive option, despite its greater costs and evidence that it does not provide a survival benefit.
Studies Find CPM Rates Are Increasing
In 2007, the first study to look at data on this topic found that rates of CPM had gone up 150 percent between 1998 and 2005. Several subsequent studies have shown the rates continuing to increase. A 2011 study from Memorial Sloan Kettering breast surgeon Tari King found that only 13 percent of patients who chose CPM had a known risk factor for an increased risk of cancer in the other breast. (Those risk factors include mutations in one of the BRCA genes or a history of radiation therapy to the chest wall.)
“We found that women who have a family history of breast cancer were more likely to choose this option, even if they did not have a BRCA mutation,” Dr. King says. “We also found that women who are younger tend to choose CPM more frequently.”
“We know from other studies that most women significantly overestimate their risk of developing a second cancer, so it is very important that patients understand all the potential risks and benefits of this approach,” she says. “Removing the other breast increases the length of the operation and the risk of complications. And some women may be dissatisfied with the outcome of their reconstructive surgery, either on one side or both sides.”
Dr. King estimates that today, the rate at which women with cancer in one breast choose CPM is 35 to 40 percent.
A Changing Landscape
Dr. King believes there are several reasons for the increase. “One thing we found in our study is that women who had a breast MRI as part of their preoperative evaluation were three times more likely to choose CPM,” she says. MRIs may detect additional areas of breast cancer that are missed by mammography, but the rate of false positives is quite high. “If the MRI finds something that looks suspicious, many women say, ‘I would rather just have a double mastectomy than go through the process of having biopsies on my other breast,’” she notes.
“Another factor is the advances in breast reconstruction and the availability of immediate breast reconstruction,” she says. “There are certainly improved results for these procedures today compared to a decade ago.”
Another potential reason for the increase is “more public conversation about breast cancer and the willingness of people to talk about the choices they’ve made. Increasingly, that choice is CPM,” Dr. King says. “Whether it’s a famous person or someone who lives down the street from you, hearing about other people’s treatment can have an influence on your choices, potentially creating a sense of acceptance that more-extensive surgery is preferable or necessary.”
“We treat so many truly thoughtful, educated women,” adds Mary Jane Massie, a Memorial Sloan Kettering psychiatrist who specializes in treating women with breast cancer. “Every woman who comes here has heard a story about a woman who was told by her doctor that that she didn’t need a double mastectomy and then later had cancer in both breasts.”
“The anxiety and fear that patients feel in these situations is very real,” Dr. Massie says.
Empowering Women to Make Choices
“There can sometimes be a disconnect between the information that women are receiving from friends and family and the information they receive from their physicians,” Dr. King says. “The strongest point we can make to empower women to consider less-extensive surgery is that there is no survival advantage to CPM, and that removing a healthy breast is not better treatment.”
“It’s also important to recognize that mastectomy decreases the risk of a contralateral breast cancer by 95 to 97 percent. There is no 100 percent guarantee,” she says.
“Women need to feel supported in their choices whatever they decide to do,” Dr. Massie says. “It’s our job as doctors to teach patients, but it’s not always as simple as just showing them statistics.”
Current data show that most women with breast cancer have a very small risk of developing cancer in their other breast; only about 3 to 5 percent of those women will develop a cancer in their healthy breast over the next ten years. And Dr. King points out that this risk has actually decreased over the past decade thanks to advances in hormone therapy and other systemic therapies that patients often receive as treatment for their first cancer.
“We don’t want women to choose unnecessary surgery simply because of anxiety,” Dr. Massie concludes. “No two women are the same, and every woman needs to have a conversation with her doctor about what the risks and benefits are for her own situation.”