Women who possess BRCA1 or BRCA2 genetic abnormalities are still susceptible to cancer beyond the age of 50, even if they have never been diagnosed with the disease before. Although these mutations are typically linked with an earlier onset of breast and ovarian cancer, the risk remains significant as women age.
A recent study, published in the journal Cancer, has reported its findings on over 2000 women from 16 countries, between the ages of 50 and 75. All participants were aware of their BRCA mutation status and had no history of cancer. The study concluded that the cumulative risk of developing any type of cancer after the age of 50 was 49% for those with a BRCA1 mutation and 43% for those with a BRCA2 mutation.
Kelly A. Metcalfe, PhD, who is the lead author of the study explained: “What is striking about our results is that breast and ovarian cancers were the most frequently observed cancers occurring and that is concerning, considering we know how to reduce the risk of cancer in women who have these genetic risk factors.’
Additionally, for those in the study who had not undergone cancer risk-reducing surgery, the risk was even higher at 77% for those with a BRCA1 mutation and 67% for those with a BRCA2 mutation. These results reinforce the significance of continuous cancer monitoring and genetic testing for women with BRCA mutations, particularly those who have not undergone risk-reducing surgery.
The study reports that only 15% of the women involved opted for preventive bilateral mastectomy, while 43% underwent bilateral salpingo-oophorectomy (BSO) – a procedure that involves the removal of both ovaries and fallopian tubes – before they turned 50 years old. The research highlights that these women had the lowest risk of developing any form of cancer, with the incidence rate being just 9%. These results emphasise the importance of considering preventive surgeries as an option for women with a BRCA mutation, particularly those who are under the age of 50.
Data regarding the recommendations provided by care providers to the women in this study were not collected. It is possible that some women were not informed about the heightened cancer risks between the ages of 50 and 75 years. The reasoning behind the women’s decision to forgo preventive surgery is also unknown. The participants in this study received counselling between 1995 and 2020, and any clinical follow-up received since the disclosure of their positive results is not available to us. It is important to note that advances have been made in our understanding of the management of women with a BRCA1 or BRCA2 pathogenic variant, emphasising the significance of continued monitoring by cancer genetics specialists. Further studies targeting this age group are necessary to understand their comprehension of risk and decision-making processes. This study does not report on mortality, and a future research will focus on this topic.
The Screen Project Canada, which is located at Women’s College Hospital, is a consumer-based genetic testing model that enables individuals to pay for genetic testing to determine whether they carry a BRCA1 or BRCA2 mutation, irrespective of their family history. While it currently incurs a small cost to the patient, Metcalfe believes that lowering the barriers to genetic testing will not only save lives but eventually become a standard part of cancer care in Canada.