Why Many Women Opt for a Double Mastectomy

Susan Derwin saw a call coming in. She had turned 60 that day, but this would not be a celebratory message. 

It was her doctor’s office calling, with results from her routine screening mammogram. Derwin was told the scan had picked up something in her left breast, and she would need to come back in for more tests.

“In my gut, I just felt sure it was cancer,” Derwin said.

She was right. 

On a Monday evening about 2 weeks later, Derwin received a call from her doctor confirming she had cancer in her left breast. The next day she met her breast surgeon. 

“It was all very fast,” she said.

Surgery would be the first step — an option she knew intimately, after her sister’s breast cancer surgery 13 years prior. 

Derwin’s surgeon told her that a mastectomy was the best approach, but it was up to her to decide between removing one breast or both.

For most women with cancer in one breast, double mastectomy has never been shown to lower the likelihood of dying from the disease. 

A recent study published in JAMA Oncology hammered that point home. For patients with cancer in only one breast, their choice of surgery — whether lumpectomy or single or double mastectomy — made no difference in their risk of dying of the disease over the next 20 years.

Derwin also knew that a double mastectomy would not prevent the cancer from coming back; adjuvant chemotherapy and hormonal therapy were her best chances at that.

But Derwin made the call to go with double mastectomy with flat closure, just like her sister had done.

“Once the decision was made, I never second-guessed it,” she said.

Derwin is hardly alone. Many women with cancer in one breast opt to remove both. 

Double mastectomy rates began rising in this population in the late 1990s and have remained high, even after research in the late 2010s began to show that the more extreme surgery did not improve survival rates. 

Why the apparent disconnect?

The decision to have a unilateral or bilateral mastectomy is more complicated than simply weighing the survival stats.

Despite the survival data, a double mastectomy may offer some women a greater feeling of safety. For others, there’s the physical, mental, and financial toll of ongoing screenings and possible biopsies. And some women also prefer the aesthetic symmetry of removing both breasts. 

It can be hard to understand why a patient would want more surgery if it’s not necessary to treat the cancer, said Seema Ahsan Khan, MD, professor of breast surgery, Northwestern University Feinberg School of Medicine, Chicago. But “I do think we really underestimate the burden of screening” and other issues, she said. 

Overestimating Benefit

One major reason that average-risk patients with cancer in one breast opt for a double mastectomy is that many of them overestimate their risk of developing cancer in the other breast. 

“It’s something we spend a lot of time talking about with people,” Laura Dominici, MD, breast surgical oncologist at Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston.

Women who have had breast cancer do face a higher-than-average risk of getting cancer again, and that includes breast cancer. But overall, the risk of developing a new cancer in the other breast is quite low: between 0.1% and 0.6% per year. 

A bilateral mastectomy does cut that already low risk. The recent JAMA Oncology study found that the 20-year cumulative incidence of contralateral breast cancer was just 0.7% after a bilateral mastectomy, vs 7.8% after lumpectomy and 6.1% after unilateral mastectomy. 

Patients also often overestimate the potential life-saving benefits of a double mastectomy. Although double mastectomy reduces the risk of a new cancer developing in the other breast, the JAMA Oncology study revealed that this surgery does not impact breast cancer mortality. At 20 years, the cumulative breast cancer mortality rate was 16.7% after bilateral or unilateral mastectomy, and 16.3% after lumpectomy. 

Explaining to patients that, even with a lower risk for contralateral breast cancer, a double mastectomy doesn’t ultimately improve survival is key to laying out the pros and cons, said Puneet Singh, MD, assistant professor of breast surgical oncology at the University of Texas MD Anderson Cancer Center, Houston. Improving survival depends on other factors, including the use of hormone therapy, which has been shown to reduce the risk for recurrence and death from breast cancer in women with early-stage estrogen receptor–positive disease.

There are also potential risks associated with undergoing the more invasive procedure, with some data indicating that bilateral mastectomies come with higher rates of adverse events.

“The longer the procedure, the longer the recovery, and there’s the possibility of increased complications like flap necrosis and infection,” Khan noted.

Still, the data on this remain mixed, and other research has found no significant differences between the complication rates. It’s ultimately the breast reconstruction surgery that more definitively bumps up a patient’s risks for complications.

The Burdens of Screening

Outside of survival outcomes, double mastectomy does come with some notable benefits for patients.

Many patients consider double mastectomy as a way to free themselves from years of regular imaging. For women with dense breasts, that may include supplemental screening with MRI or ultrasound.

Becky Barber, 65, says “scanxiety” was top of mind when she opted for a double mastectomy about 2 years ago. Her cancer had come back in the same breast, following a lumpectomy and radiation more than 20 years ago. 

Her initial cancer was ductal carcinoma in situ (DCIS). But the new one was invasive.

“A single mastectomy would’ve been an option,” said Barber, who lives near Raleigh, North Carolina. “But after many years of [benign] things showing up on scans — and I’ll tell you, a stereotactic biopsy is like torture — I just thought, I don’t want that again. I was done.”

Barber says her surgical oncologist did not try to push her in any direction. Barber opted for a double mastectomy, and she’s happy with her decision.

“I think imaging can create a lot of anxiety for women,” Singh said, “even if they know there’s a low risk that we’re going to find something in the other breast.” 

Providers probably underestimate the burden of screening, especially for women who need supplemental screening, Khan said. There’s a heavy “investment of time and energy, the anxiety of anticipation, and out-of-pocket costs,” she said.

Cost is a major part of the equation for Tarah Brown, a 42-year-old from Ventura, California, who recently underwent surgery for DCIS and stage 1 invasive ductal carcinoma. Instead of having “a very big” lumpectomy, followed by radiation, Brown opted for a single mastectomy. 

But now she’s considering removing the other breast.

For Brown, the decision will hinge on her screening outlook. She has very dense breasts and says her cancer was not detected during her routine screening mammogram; it was only diagnosed after she felt a lump and underwent diagnostic mammography and ultrasound. 

“I think the decision is going to come down to, if mammograms can’t tell me if I have cancer, then am I going for an MRI every year?” Brown said. “How expensive is that? Will insurance pay for it?”

She has already had one biopsy of her remaining breast, after an MRI of both breasts following her diagnosis detected an abnormality. 

The biopsy “turned up nothing,” Brown said, but she’s concerned about subjecting herself — and her husband and child — to that screening waiting game for years to come.

Other Key Factors

For Derwin, symmetry was a big concern when choosing between removing one or both breasts.

Derwin said her surgeon “remained very objective,” never trying to steer her in either direction. 

Initially, she wanted to wait for her BRCA test results before deciding. 

A patient’s BRCA status does make a difference. For known BRCA1/2 mutation carriers, studies have shown a 30%-40% increased risk for contralateral breast cancer at 10 years, and the risk appears to continue beyond that point. A 2016 consensus statement from the American Society of Breast Surgeons recommends that women with a BRCA mutation consider contralateral mastectomy, given their elevated risk for contralateral breast cancer.

But Derwin’s test results were delayed, which meant she’d have to make a choice about her surgery before knowing her BRCA status.

Derwin made the call to go with double mastectomy with flat closure because she wanted the symmetry.

Symmetry is an important consideration for many women — whether patients opt for reconstruction or a flat closure.

“I’ve definitely had patients who’ve expressed similar preferences and values,” Singh said.

Ultimately, Derwin’s decision to have a double mastectomy was a fortunate one. When her genetic test results did eventually come in, she found that she carried a BRCA1 mutation.

Tailoring the Conversation

When Dominici talks to patients, she begins by discussing how to treat the existing cancer. 

But for women with cancer in one breast, Dominici will ultimately shift the conversation to the other breast and walk them through the data on a double vs single mastectomy.

“A lot of women come in knowing what they want,” said Dominici. But sometimes understanding the evidence will sway a patient in a different direction. 

“There are some who say, ‘I didn’t know all of that,’ and think they no longer want a double mastectomy,” she said. And there are others who listen but ultimately decide a double mastectomy is the right choice for them.

To Singh, what matters is that the back-and-forth happens. “There’s a lot of information that I can provide, based on my experience and the data out there,” she said. “But what’s really important is listening to the patient, trying to understand where they’re coming from, and tailoring the conversation to that.”

Dominici agreed, adding that it’s important to make the scientific evidence not only digestible, but also relevant to the individual — considering their personal values and preferences. 

Beyond the hard numbers, Dominici also shares different approaches for achieving symmetry, outside of a double mastectomy, which include a breast lift or breast reduction for the opposite breast.

“I really do see our role as being the steward of information,” Dominici said. “And I think it’s important that women are heavily involved in figuring out what the right choice is.”

At the same time, it’s a lot of information for women to process while they’re grappling with a new cancer diagnosis.

“One thing I try to leave people with is that it’s OK if things need to slow down a little,” Dominici said. If patients feel torn about the right surgical option for them, “we can give women space to let things settle and give them a chance to breathe,” she said.