Over the last 10 years, the number of women with early stage breast cancer in the U.S. choosing to have both breasts removed in a preventive but aggressive procedure known as contralateral prophylactic mastectomy (CPM) has more than doubled. A research team from the University of California, San Diego (UCSD), searching for reasons for this trend through an online breast cancer community, found that fear of recurrence was the driving force.
The results were presented at the 2016 Clinical Congress of the American College of Surgeons, which took place Oct. 16–20 in Washington, D.C.
Researchers also looked at community postings to see what information was being shared between patients.
CPM is increasingly being used by patients at all stages of breast cancer, the researchers noted, even those with the earliest and lowest-risk cancers — Stage 0 ductal carcinoma in-situ, a non-invasive cancer of the lining of the breast milk duct usually treated by lumpectomy plus radiation therapy.
Recent data suggests that up to 25 percent of newly diagnosed patients are undergoing CPM, representing about half of women undergoing mastectomies, the researchers also noted in a press release. In 2006, in contrast, only about 5 percent of breast cancer patients had CPM, accounting for 10% to 15% of mastectomy procedures performed that year.
The research team searched for specific keywords, including “contralateral,” “prophylactic,” and “double mastectomy,” to identify relevant posts. Of the 20,189 posts on that breast cancer community, 1,120 related and, of these, 541 from 286 posters were found to be relevant. Of those posters, 226 were patients and 197 of them had previously made the decision to undergo CPM, while 29 were still undecided.
In addition to fear of recurrence, another main reason for choosing the procedure was the perception that CPM is the best treatment available for breast cancer, the researchers found. Some patients wrote of having already experienced a recurrence of the disease, and opted for CPM to prevent another return. Others also mentioned CPM being recommended by plastic surgeons to optimize cosmetic reconstruction outcomes.
Rebecca Marmor, the study’s lead author, thought the growing rate of CPM was curious, given the historical context of breast cancer treatment. Until 1980s, mastectomy was the standard of care, but “as large trials came out demonstrating the efficacy of breast conservation, I think a lot of surgeons assumed that breast conservation would be patient’s preference,” said Marmor, a general surgery resident in UCSD’s Department of Surgery and a Division of Biomedical Informatics’ clinical informatics fellow. “We want to understand what is motivating some women who are choosing CPM, and sometimes even demanding it in the face of resistance from their own surgeons and oncologists.”
Marmor added that while earlier studies had looked at the increase in CPM, her team was able to follow communication between patients themselves.
“Now we have a better understanding of what beliefs some patients hold, which is that CPM is the best treatment for breast cancer. We also were able to study what patients are saying to each other about CPM. Now that we have a sense of what they’re saying to each other, we want to work to correct their misconceptions,” she said.
Researchers are now performing the same analysis on another health community to test the results’ consistency.