Study Finds No Survival Advantage For Bilateral Mastectomy Versus Breastconserving Surgery Plus Radiation

NEWS FROM THE NCI

Issue 24 Winter/Spring 2015

The percentage of U.S. women diagnosed with cancer in one breast who opt for the removal of both breasts continues to rise. However, a recent study found no evidence that bilateral mastectomy offers any survival benefit compared to lumpectomy followed by radiation therapy.

The study, partially funded by the U.S. National Cancer Institute, looked at California Cancer Registry data from 1998 to 2011. The data included information on the treatment choices and outcomes of almost 190,000 women diagnosed with cancer in one breast.

According to the researchers, the rate at which these patients opted for double mastectomy jumped from only 2 percent in 1998, to more than 12 percent by 2011.

The rise was especially sharp among younger women: By 2011, a full one-third of patients aged 40 and under were choosing bilateral mastectomy, the study found.

However, the researchers found no drop in mortality for women who had both breasts removed, compared to those who opted for lumpectomy plus radiation.

"We can now say that the average breast cancer patient who has bilateral mastectomy will have no better survival than the average patient who has lumpectomy plus radiation," study lead author Dr. Allison Kurian, assistant professor of medicine and of health research and policy at Stanford University, said in a Stanford news release.

"Furthermore," she noted, "a mastectomy is a major procedure that can require significant recovery time and may entail breast reconstruction, whereas a lumpectomy is much less invasive with a shorter recovery period."

The study, published in the Journal of the American Medical Association, also identified subsets of women who seemed more likely to opt for bilateral mastectomy. Kurian's team found that more affluent, white women under 50 were the group most prone to make this treatment choice.

Importantly, the study's findings don't mean that a woman with a BRCA1, BRCA2 or other gene mutation known to increase the risk of developing breast cancer, or with a strong family history of breast cancer, should not get a bilateral mastectomy. For women with a genetic predisposition, removing both breasts is an effective option.

In an accompanying journal editorial, Dr Lisa Newman, director of the Breast Care Center at the University of Michigan, said that many women may make certain assumptions about their options for breast cancer care.

"Patients presume that [bilateral mastectomy] represents their best chance for cure from the known cancerous breast, while also eliminating a perceived inevitable threat posed by the unaffected breast," Newman said.

But she cautioned that the very real concerns of women caught in the "dense fog of complex emotions" following a breast cancer diagnosis should not be dismissed.

The best course of action — to help women clearly understand the risks and benefits of various treatment options — is to give them a little bit of time, Newman believes.

"Patients should be encouraged to allow the intensity of these immediate reactions to subside before committing to mastectomy prematurely," she said.