An increasing number of women in the United States who have breast cancer diagnosed in one breast are opting to have both breasts removed. The rate of contralateral prophylactic mastectomy has increased 5-fold in the past 10 years, even though there is no evidence that this improves survival.
A new study, the largest of its kind to date, outlines the downsides of this decision. It shows that undergoing a double (bilateral) mastectomy is associated with a significantly higher risk for certain complications when compared with a single (unilateral) mastectomy. These include a higher risk for implant loss, a higher risk of needing a blood transfusion and a reoperation, and a longer hospital stay, although the rate of complications for both types of procedure remains very low.
Women who are considering having a double mastectomy should be educated about these risk, commented lead author Mark Sisco, MD, a clinical assistant professor of surgery at the University of Chicago Pritzker School of Medicine.
Dr. Sisco was speaking at a presscast held by the American Society of Clinical Oncology ahead of the 2014 Breast Cancer Symposium in San Francisco, where the study will be presented.
"This is really some of the first data that we have seen that allows the surgical team to quantify for a woman who is contemplating surgery what exactly are the risks of the larger operation of double mastectomy," commented Harold Burstein, MD, from the Dana-Farber Cancer Institute in Boston, who moderated the presscast.
In a statement, Julie Margenthaler, MD, from the Breast Cancer Symposium news planning team, commented: "For the average-risk woman with breast cancer who does not have an inherited mutation, there is often an estimation of future risk, which may result in more extensive surgical procedures than are warranted."
Around 20,000 Women Each Year
Our best estimates suggest about 20,000 women in the United States each year, maybe even as many as 30,000 per year, opt for a double mastectomy when they are diagnosed with breast cancer, Dr. Sisco said. There are many reasons that a woman may choose this option, including increased peace of mind, wanting to achieve better symmetry, being able to forgo mammograms or additional surveillance, and there still is a perception among women that the cancer will be less likely to return, he commented. However, he added, "these women will not live longer by having a double mastectomy."
But what about the downsides of the procedure? Here the data are lacking, as there have been only a few small studies with inconsistent findings, he said. So the team set out to collect these data so that they could be provided to women who are contemplating this procedure and to improve the process of informed consent.
For their study, Dr. Sisco and colleagues looked at 30-day postsurgery complications for 18,229 women who had undergone either single or double mastectomy, using records from the American College of Surgeons National Surgery Quality Improvement Program Participant User Files (2005 to 2012).
Dr. Sisco emphasized that all the women had been diagnosed with breast cancer.
More than half these women had a single mastectomy (n = 11,727; 64.3%) and the others had a double mastectomy (n = 6502; 35.7%).
Most women had an implant-based reconstruction (79.6% of those who had a single mastectomy and 88.6% of those who underwent a double mastectomy).
Among the women who underwent an implant-based reconstruction, there was a significantly higher rate of 3 complications in women who had a double mastectomy compared with those who had a single mastectomy, as follows:
implant loss (1% vs 0.7%; adjusted odds ratio [aOR], 1.55; P = .02)
blood transfusion due to bleeding-related complications (0.8% vs 0.3%; aOR, 2.20; P < .001)
reoperation — i.e., a second operation within 30 days (7.6% vs 6.8%; aOR, 1.14; P = .05).
Among the women who underwent autologous reconstruction (a less common but more complicated procedure involving the woman's own tissue, Dr. Sisco explained), the risk of needing a blood transfusion was raised even more — the rates for blood transfusion were 7.9% for double vs 3.4% for single mastectomy (aOR, 2.34; P < .001).
And in both cases, women who underwent a double mastectomy had a significanty longer hospital stay than those who opted for a single mastectomy (2 days vs 1 day for implant-based reconstruction, and 5 days vs 4 days for autologous reconstruction; P < .001).
There were no significant differences in rates of medical complications (heart attacks, pneumonia, etc.), surgical-site infection, or wound disruption between the 2 procedures for either type of reconstruction, the researchers note.
Summarizing the take-home messages, Dr. Sisco said that both procedures are generally very safe and have a low rate of complications, but there are several complications that are more likely with a double vs a single mastectomy.
It is critical that this information is discussed and considered by women as they contemplate surgery for breast cancer, he concluded.
The study was funded by the section of plastic surgery at the University of Chicago Pritzker School of Medicine. Dr. Sisco reports having a consultancy with Gerson Lehrman Group, and patents/royalties/intellectual properties with Pfizer. Dr. Burstein has disclosed no relevant financial relationships.
2014 Breast Cancer Symposium (BCS): Abstract 62. To be presented September 4, 2014.
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Cite this: Downsides of Double Mastectomy for Single Breast Cancer - Medscape - Sep 04, 2014.