Genetic Cancer Risks

It is estimated that about 1% of women carry the BRCA1 or BRCA2 gene for breast cancer and these genes are believed to be responsible for 3% - 8% of all breast cancers.

The topic of genetic testing and breast cancer is generating an increasing amount of attention. Although, there are many genes that are involved in the development of breast cancer, most discussion focuses on the recent discovery of the BRCA1 and the BRCA2 genes. Having the BRCA1 or BRCA2 gene may raise a women's risk of developing breast cancer from about 11% to anywhere from 50% to 85% during her lifetime.

Unlike other types of tests genetic testing only predicts the likelihood of developing breast cancer and does not mean that the disease will occur. This type of ‘predictive' testing separates high-risk family members into those truly at high risk who will likely benefit from enhanced early detection or breast cancer prevention strategies from those at the same risk as the general population. There is little known about the effectiveness of prevention strategies for those identified to be at high-risk. Additional research is required before BRCA1 or BRCA2 testing becomes recommended as part of routine practice.

Source: Health Canada