Double mastectomy doesn’t improve breast cancer survival rate
Countless women who have been diagnosed with breast cancer have opted for aggressive treatments, like having a double mastectomy even though the tumor was confined to one breast. A large new study published in JAMA Oncology indicates that extra precaution may not be warranted.
The study included data on more than 661,000 women in the U.S. over 20 years. It concluded that there is no survival advantage to removing the healthy breast.
The results were not a surprise to breast surgeon Jill Oxley, MD, FACS, who is the medical director of breast care services for Cape Cod Healthcare.
“This is just another study that proves what we’ve known for years, but is still a very common misconception,” she said. “A lot of the reasons that women will choose to have the opposite unaffected breast removed are to reduce what they think is a high risk of getting a contralateral breast cancer. But this risk is actually fairly low. It’s less than half of a percent per year and so the 20-year risk is now shown to be about 7 percent.”
The push to avoid what is termed as “contralateral prophylactic mastectomy” really started with the Choosing Wisely campaign, Dr. Oxley said. The campaign was part of the American Board of Internal Medicine’s recommendations that began in 2012 with nine national specialty societies and then grew to more than 80 today. Its goal was to develop strategies to reduce overuse and unnecessary medical services to improve patient outcomes.
“The breast-related ones were adopted by the American Society of Breast Surgeons back in 2016 and one of the breast cancer-related ones says ‘don’t routinely perform a double mastectomy in patients who have a single-breast cancer,’” Dr. Oxley said. “This study just really reinforces what we know – that there is no survival benefit from removing the other breast.”
Some Women Opt for It Anyway
But Dr. Oxley pointed out that there are some reasons women choose to have a double mastectomy. For some women, the anxiety about getting a second cancer and ongoing screening is overwhelming enough that a double mastectomy is warranted. Other women chose a double mastectomy for reasons of symmetry. That is true regardless of whether the patient decides to have reconstruction surgery. Also, a double mastectomy can be beneficial to women who are carriers of the BRCA gene.
One of the common and unfortunate misconceptions women have is that they think if they have a mastectomy, they don’t need further treatment with radiation, medication or chemotherapy, which is not the case, Dr. Oxley said.
“The treatment recommendations are going to be made based on the characteristics of the cancer itself, not what we’ve done to the breast,” she said.
For every breast cancer, Dr. Oxley tells patients there are two issues that need to be addressed:
- How to get the cancer out of the breast and give the patient the best chance for it not coming back. That becomes a decision between a lumpectomy, usually with radiation, or a mastectomy.
- How much of a worry it is that the cancer will show up elsewhere in the body down the road. That is determined by the staging of the breast cancer, not what surgery is done. Staging is about the actual characteristics of the cancer itself.
“The important difference is between stage 1 and stage 2 or 3, because stage 1 breast cancer is highly unlikely to be the cause of death, but stage 2 or stage 3 is going to need more aggressive medical treatment,” Dr. Oxley said.
“These women might need mastectomy and radiation for treatment. But with the earlier stage cancer there’s no survival benefit for removing the breast. Those women are going to do well pretty much regardless of what surgery they do because modern systemic therapy is so effective.”
