Young women overestimate cancer risk in second breast

Many women with breast cancer overestimate their risk for developing the disease in the unaffected breast and undergo contralateral prophylactic mastectomy (CPM) despite knowing that this procedure does not clearly improve survival.

The cross-sectional survey yielding these findings was conducted by a group led by Shoshana Rosenberg, ScD, MPH, of the Susan F. Smith Center for Women’s Cancers at Dana-Farber Cancer Institute in Boston, Massachusetts.

“An increasing percentage of women treated for early-stage breast cancer are choosing to have CPM,” pointed out Rosenberg in a statement issued by Dana-Farber to accompany the release of the survey findings in Annals of Internal Medicine (2013;159[6]:373-381). “The trend is particularly notable among younger women.”

To examine preferences, knowledge, decision making, and experiences of young women with breast cancer who choose CPM, Rosenberg and fellow investigators surveyed 123 women from eight academic and community medical centers who had received a diagnosis of breast cancer at age 40 years or younger between November 2006 and November 2010. None of the survey respondents had bilateral breast cancer, but all had undergone bilateral mastectomy a median of 2 years before being surveyed.

The 23-item survey included items related to decision making, knowledge, risk perception, and breast cancer worry. The results revealed the following:

• Most women indicated that desires to reduce their risk for contralateral breast cancer (cited by 98% of respondents) and improve survival (cited by 94% of respondents) were extremely important or very important factors in their decision to have CPM.
• Nevertheless, only 18% of the respondents indicated that women with breast cancer who undergo CPM live longer than those who do not; most respondents expressed understanding that removing both breasts would not extend survival for women who do not have a genetic predisposition to breast cancer.
• Women who carried the BRCA1 or BRCA2 mutation more accurately perceived their risk for contralateral breast cancer, whereas women without a known mutation substantially overestimated this risk.

“Most women acknowledge that CPM does not improve survival, but anxiety and fear of recurrence probably influence them during the decision-making process,” explained Rosenberg and colleagues in their report. They noted that interventions are needed to improve risk communication and promote evidence-based decision making.