Women who have inherited a BRCA1 or BRCA2 gene mutation will have a clearer picture of the risk of breast and ovarian cancer thanks to a study co-led by Cancer Council Victoria, the Peter MacCallum Cancer Centre, and the University of Melbourne.
Ten thousand women in Australia, the United States and Europe took part in this international study over 20-years and the data gives us much more precise information than ever before. The study found that women with BRCA1 mutations have on average a 72% risk of developing breast cancer by 80 years of age. For BRCA2 mutation carriers, the risk of breast cancer is 69%. The average lifetime risk of ovarian cancer is 44% for BRCA1 and 17% for BRCA2.
The study also found that the cancer risk peaked for women in their 30s with BRCA1 and 40s for carriers of BRCA2 gene mutations, but both types remained at the same high risk later in life.
Co-author and Head of the Cancer Epidemiology & Intelligence Division at Cancer Council Victoria, Associate Professor Roger Milne said the findings gave women greater knowledge to help them make some pretty tough decisions.
“The message we’d like women to consider is this; if you have a family history of breast cancer but don’t know if you’re a carrier and would like to know, it’s important to get tested at a younger age than previously thought,” he said. “That way you’re better able to explore personalised prevention options such as medication, surgery and lifestyle changes.”
Further analysis is taking place to determine how modifiable lifestyle factors such pregnancy, contraceptive and hormone replacement medication, or alcohol and smoking influence cancer risk for these women at already high genetic risk.
Researchers believe that the data will show that it’s not solely a woman’s genes or environment that cause cancer, but rather a combination of the two. Having a better understanding of these modifiable factors will allow for improved prevention strategies that can be tailored to individuals.
It was only because of our supporters that Cancer Council Victoria was able to help conduct this game-changing research. Thank you.