University of Toronto

Funded By: 

Canadian Institutes of Health Research


Data Collection Complete


Women with a BRCA1 or BRCA2 mutation have one of the highest known risks for the development of breast and ovarian cancers.  The average lifetime risk of breast cancer is up to 87% and the lifetime risk of ovarian cancer is up to 39%.  Fortunately, there are options available for women to lower their risk of both breast and ovarian cancers.  Thus, the value of genetic testing for BRCA1 and BRCA2 is to identify high-risk women, and ultimately reduce the number of cancers occurring, and in-turn, reduce the number of women dying of the disease.  However, this goal can only be achieved if women do elect for a cancer prevention option.  In Canada, we have observed marked differences in uptake depending on where in the country a woman received her genetic counseling and testing.  The ranges in uptake of the options were quite substantial, ranging from 8 to 46% for prophylactic mastectomy, 39 to 67% for prophylactic oophorectomy, and 4 to 16% for tamoxifen. We do not currently understand why these differences exist.  In this study, the aims were to determine the reasons for the differences in uptake of preventive options in Canadian women with a BRCA1 or BRCA2 mutation.  By understanding the reasons for the differences, we can aim to address the differences to ensure that all Canadian women who undergo genetic testing for BRCA1 and BRCA2 receive consistent care.