A new study has analysing nearly 10,000 women with the mutations found that they have a 70 per cent chance of developing breast cancer during their life. This is in comparison to the average Australian woman who has a 12% chance of developing the disease in their lifetime.
They also found that the risk was influenced by both specific mutations within their genes and the occurrence of the disease in close close family members.
Women with the genetic mutation found at specific locations in the two BRCA1 or BRCA2 genes were around twice as likely to get breast cancer. Those with close relatives who had breast cancer (like a mum, sister or aunt) were also found to be twice as likely to develop the disease before they turned 70, than those who didn’t.
Researchers say this new information could be beneficial for health professionals who council women about their risk factor.
Experts say the BRCA1 and BRCA2 gene mutations are relatively rare, so testing for them only usually occurs when the person's family history suggests it might be present.
These factors associated with a higher risk of carrying the mutation include:
- Breast cancer diagnosed before age 50 years
- Cancer in both breasts in the same woman
- Both breast and ovarian cancers in either the same woman or the same family
- Multiple breast cancers
- Two or more primary types of BRCA1- or BRCA2-related cancers in a single family member
- Cases of male breast cancer
- Ashkenazi Jewish ethnicity
Always speak to a doctor if you are concerned about your risk factor.