Young women who elect contralateral prophylactic mastectomy do so, in part, because they want to improve their chances for survival, even though they realize there is no convincing evidence of a survival benefit, based on results from a survey.
Moreover, many women, particularly those without a known BRCA mutation, substantially overestimate their risk of developing cancer in the unaffected breast, Shoshana M. Rosenberg, Sc.D., of the Dana-Farber Cancer Institute and the Harvard School of Public Health, both in Boston, and her colleagues reported in the Sept. 17 issue of Annals of Internal Medicine.
The findings suggest "some degree of cognitive dissonance," since almost all respondents cited both the desire to improve survival or extend life and a desire to prevent metastatic disease as extremely or very important reasons for choosing contralateral prophylactic mastectomy, while also demonstrating awareness that bilateral mastectomy would not extend survival, the researchers said. Anxiety and fear of recurrence likely influenced the decision-making process and led women to identify their desire to extend life and prevent metastatic disease as among the most important reasons for having contralateral prophylactic mastectomy.
Of 550 women diagnosed at age 40 years or younger with breast cancer in one breast, 123 (22%) who underwent bilateral mastectomy were included in the analysis. Of those women, 94% said the desire to improve survival was an extremely or very important factor in their decision to undergo contralateral prophylactic mastectomy. Yet 74% of mutation carriers and 84% of noncarriers acknowledged that most women who are diagnosed with early-stage breast cancer and undergo treatment will ultimately die of something other than breast cancer.
Also, 98% cited a desire to decrease their risk of contralateral breast cancer and 95% cited a desire for peace of mind as extremely or very important factors in their decision (Ann. Intern. Med. 2013;17:373-81).
Mutation carriers estimated their risk of developing cancer in the contralateral breast in the 5 years after unilateral treatment at 20%, noncarriers estimated that risk at 10%. The risk for women with BRCA mutations is estimated to be 24%-31%. The group without mutations overestimated their risk, which is actually about 2%-4% over 5 years. Women in both groups estimated the risk of chest wall recurrence after bilateral mastectomy at 5%, which is actually estimated at less than 1%, the researchers noted.
Survey participants were women whose median age was 37 years at cancer diagnosis and who were recruited from four academic and five community hospitals in Massachusetts, and from one academic site in Toronto between November 2006 and November 2010. The participants were recruited as part of the Helping Ourselves, Helping Others: Young Women’s Breast Cancer Study. Most had stage I or stage II breast cancer, and all were believed to have breast cancer only in one breast. About 60% of tumors were estrogen receptor–positive, and about 25% of the women were BRCAmutation carriers.
The survey was a one-time supplement to the ongoing prospective cohort study. It is one of the largest surveys to date to examine decision-making, risk perceptions, and psychosocial aspects of contralateral prophylactic mastectomy among young women with breast cancer, the investigators said. The survey findings are important, given that the rates of contralateral prophylactic mastectomy have increased dramatically in recent years, from 4%-6% in the late 1990s to 11%-25% in more recent reports, even though "the value of the procedure for most women with unilateral early-stage breast cancer is unclear," the researchers said.
The study was limited by the lack of validation of the survey, the possibility of recall bias (since the women were surveyed an average of 2 years following surgery), and the possibility of limited generalizability of the findings because the study population was primarily white, non-Hispanic, and college educated. Yet, the findings highlight a need for improved communication with patients, they said.
Although 96%-97% of participants believed they were clear about benefits and risks, and which mattered most, many women reported that several outcomes associated with surgery were worse than they had expected. For example, 33% reported needing a higher-than-expected number of operations or procedures, and 28% said that numbness or tingling in the chest was worse than expected.
"With respect to QOL outcomes, 42% reported that their sense of sexuality was worse than they expected after surgery, and nearly one-third indicated that self-consciousness about appearance was also worse than expected," the researchers reported.
Only about half of the participants indicated that their physicians had talked at least to some degree about reasons not to have contralateral prophylactic mastectomy, suggesting a potential role for "interventions that ensure women are sufficiently informed and the actual risk for contralateral disease is effectively communicated," the investigators said.