Double Mastectomy Rates Increased

Bilateral mastectomy rates increased among breast cancer patients in California study

(RxWiki News) Double mastectomy hit the news last year when Angelina Jolie reported having the procedure. But new research suggests that the surgery has been on the rise for over a decade.

The new study looked at rates of double, or bilateral, mastectomy in California between 1998 and 2011.

During that time, rates of the procedure increased, but the study authors saw little improvement in patients' life spans.

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"This phenomenon has been seen only since 1998, which isn’t actually that long ago," said Cary Kaufman, MD, FACS, a breast surgeon and specialist at Bellingham Regional Breast Center in Washington state. "Even in 1998, young women with breast cancer were anxious and had the reflexive response to have a bilateral mastectomy. Yet, calmer advice from physicians noting no survival advantage was accepted and most young women did not opt for contralateral prophylactic mastectomy (CPM) [removal of the noncancerous breast]."

According to the authors of this new study, which was led by Allison Kurian, MD, of the Stanford University School of Medicine in California, double mastectomy — the removal of both breasts — has become more common, although much about its use is still unknown.

The procedure is sometimes used in women who only have cancer in one breast, called unilateral breast cancer, as a preventive step.

The authors wanted to better understand double mastectomy and how it compared to other treatments, including the removal of only one breast (unilateral mastectomy) and procedures that only remove part of a breast (breast-conserving surgery) combined with radiation therapy.

To do so, the authors used the California Cancer Registry to identify 189,734 women diagnosed with unilateral breast cancer in the state between 1998 and 2011. The patients were followed for an average of 7.4 years.

Dr. Kurian and team found that rates of bilateral mastectomy increased significantly — from occurring in 2 percent of patients in 1998 to 12.3 percent in 2011.

Use of double mastectomy especially increased among women younger than 40. For these patients, the rate rose from 3.6 percent of patients in 1998 to 33 percent in 2011.

"This study looking at the use of breast cancer surgery provides much data regarding these procedures," Dr. Kaufman told dailyRx News. "What is doesn’t provide is the answer as to why women choose one procedure over another when they have all options. We first look at reasons which may be related to the type of breast cancer or the likelihood that the patient will develop a second breast cancer in the future. Yet, these reasons do not seem to explain the marked increase in use of mastectomy and bilateral mastectomy in the last 10 years.

"This is a trend that has been seen across the country, not just in California. Other studies have shown that this trend is not related to the type of breast cancer that is diagnosed, not related to the likelihood of carrying the breast cancer gene (BRCA1 or BRCA2), not related to the increased use of breast MRI in diagnosing breast cancer, and most importantly, not related to the medical indications necessitating unilateral or bilateral mastectomy," Dr. Kaufman explained.

Despite the increase in double mastectomy, Dr. Kurian and team found that this procedure was not associated with lower death rates than breast-conserving surgery combined with radiation therapy. Ten years after surgery, 18.8 percent of double mastectomy patients and 16.8 percent of patients undergoing breast-conserving surgery plus radiation had died.

Both of these rates, however, were lower than the 10-year death rates for unilateral mastectomy — which were 20.1 percent.

"The underlying truth is demonstrated in this paper, that there is no survival benefit from CPM vs. breast conservation surgery (lumpectomy with radiation)," Dr. Kaufman said. "Yet women continue to be swayed by their peers to choose this more aggressive option. Like all pendulums, this trend will eventually swing back to a more medically reasonable option. We’ll just have to wait."

This study only looked at patients from one state. Further research is needed to confirm these findings and better understand why rates of double mastectomy might be increasing, the authors noted.

The study was published online Sept. 2 in JAMA.

One study author reported receiving grants (not tied to this study) from the biotech corporation Genentech. The authors cited a number of funding sources for the research, including the National Cancer Institute and the Cancer Prevention Institute of California.

Review Date: 
September 2, 2014