Background: Women affected with breast cancer who carry a BRCA1 or BRCA2 (BRCA1/2) mutation are at risk of developing contralateral breast cancer. To reduce the risk of contralateral breast cancer, some patients opt for prophylactic surgery of the unaffected breast (contralateral prophylactic mastectomy, CPM) in addition to mastectomy of the affected breast.
Methods: We conducted the present study to determine the predictors and outcomes of CPM in the year following BRCA1/2 genetic counseling and testing. Four hundred and thirty-five women affected with unilateral breast cancer who received positive or uninformative BRCA1/2 genetic test results completed assessments prior to genetic counseling and testing and 1, 6, and 12 months after receipt of results.
Results: Prior to testing, 16% had undergone CPM (in conjunction with mastectomy of the affected breast). In the year following testing, 18% with positive test results and 3% with uninformative test results opted for CPM. CPM following testing was associated with a positive genetic test result, younger age at cancer diagnosis [odds ratio (OR) = 0.94], and higher cancer-specific distress at baseline (OR = 3.28). CPM was not associated with distress outcomes at 12 months.
Conclusions: Following a positive test result, 18% of women previously affected with unilateral breast cancer had a CPM. Women affected with breast cancer at a younger age, particularly those with positive genetic test results and higher cancer-specific distress, are more likely to choose CPM than women who receive uninformative test results and who are less distressed and older at diagnosis. CPM does not appear to impact distress outcomes.