VIENNA—Breast cancer surgeons should strongly discourage most of their patients who do not test positive for the BRCA mutation from having prophylactic mastectomy, a leading European surgeon told the 2019 St. Gallen International Breast Cancer Conference. Though, he did admit that some patients were not easily convinced.
“In general, contralateral prophylactic mastectomy (CPM) in non-mutation carriers is discouraged,” said Emiel J.T. Rutgers, MD, PhD, FRCS, of the Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital and Chair of Surgical Oncology at the University of Amsterdam. This was in spite of a “tsunami” of such procedures that had overtaken the U.S. (the “Jolie Effect”) and was also affecting European countries.
Rutgers told Oncology Times that only a small proportion of non-mutation carriers should even consider having CPM. These were patients who had “mitigating factors,” such as young age (around 30), very dense breasts, and the rare CHEK2 (1100delC) germline mutation that confers three- to four-fold increased risk of breast cancer. He said that, although the presence of these risk factors could potentially provide a reason to opt for CPM, this was “a rare situation.”
Even though the evidence against using CPM in the absence of BRCA mutation had been compelling, Rutgers' center had been dealing with growing numbers of women asking for it.
“Many, many women come. [Around] one in four come to me with an early breast cancer diagnosis—perfectly fit for breast conservation and with excellent outcomes—and they ask for a bilateral mastectomy because they really think that this is better,” he noted.
Observational data pointed to the opposite, however. “The risk of a second new primary in a [BRCA mutation-negative] woman who has been treated for breast cancer is low,” he said. “It's about 0.3-0.5 percent per life-year. So, if you follow 100 [women] for 10 years, you will find 3-4 second new breast cancers.”
He added that since these were usually at early stages—due to screening—deaths from metastasis among patients with such new cancers were likely to be “really, really rare.”
“Prophylactic mastectomy will not influence life expectancy at all. It will not add a week to life expectancy,” he stated.
To back up his recommendations, he reported data from the Cochrane Library showing that, although there had been a small benefit in survival from CPM, the survey data were from women who were younger and healthier overall. And he said that recent studies had shown no survival benefit for CPM.
Rutgers warned that prophylactic surgery brought consequences. Quality of life “appeared to be less good” in women who had CPM. Before surgery, they had higher levels of anxiety. And they also were afraid of both the cancer and the possible changes of body image.
A study published in 2017 had shown that CPM had tripled among women diagnosed with breast cancer in the U.S. between 1998 and 2012 (Ann Surg 2017;265(3):581-589). But there had been no improvement in survival. Out of 496,488 patients with unilateral invasive breast cancer, 59.6 percent were treated with breast-conserving surgery while 33.4 percent had unilateral mastectomy. The remaining 7.0 percent had CPM—an overall total that included an increase from 3.9 percent in 1998 to 12.7 percent in 2012.
Also, the additional costs of including CPM in the overall treatment package were high. Rutgers said a recent estimate found that the average total treatment cost for a woman with breast cancer in the U.S. was increased by a third when CPM was added to standard surgery—an extra $11,872.
Although there was a lack of knowledge about the benefits of CPM among patients—and discussions with surgeons were commonly “incomplete”—it was common for patients to go ahead with the procedure even in the absence of clinical indications, Rutgers explained. But patients whose surgeons advised against CPM reported a much lower rate. Rutgers said that better communication with patients and more joint decision-making were high priorities to help cut present rates of unnecessary and potentially risky operations (JAMA Surg 2017;152(3):274-282).
Fear was a key to understanding the reasons women asked for CPM, he said. “Fear of cancer is, of course, very reasonable in a woman who is diagnosed with breast cancer, but there are differences in the level of fear and anxiety between women.” He said that women with the highest levels of anxiety were more likely to ask for prophylactic mastectomy “because they think they reduce the risk of breast cancer”—which he noted is not true. “The only thing they do is to increase the risk of complications of the surgery and worsening quality of life.”
There is a “real point” in sitting down with patients and explaining the risks and potential outcomes, Rutgers said. He had succeeded in making the majority of his own patients happy with breast conservation—which for most patients gave the best clinical outcomes. “Then they come back a year later and say: ‘Doctor, I'm so happy that you did this!’”
Peter M. Goodwin is a contributing writer.