Undergoing a double mastectomy reduces the risk of developing breast cancer and dying in women who have BRCA1 mutations.
- Undergoing a double mastectomy to prevent breast cancer can reduce the risk of dying in BRCA1 mutation carriers.
- However, in BRCA2 carriers, there was no difference in risk reduction whether they opted for double mastectomy or surveillance.
- Overall survival among BRCA1 mutation carriers was 90% in those who had a double mastectomy and 83% in those who preferred surveillance.
BRCA Mutations and Breast Cancer
Women who have mutations in the Breast Cancer (BRCA) have an increased risk of developing breast cancer over their lifetime. The most common mutations that predispose one to breast cancer are observed in two genes called BRCA1 and BRCA2. Women who test positive for these mutations may choose to either remove their breasts to prevent the occurrence of cancer or opt for surveillance.Study Overview
The study included 1696 BRCA1 mutation carriers and 1139 BRCA2 mutation carriers, selected from the national Hereditary Breast and Ovarian Cancer Netherlands (HEBON) database. The study aimed to follow healthy women, who opted for bilateral risk-reducing mastectomy (BRRM) or surveillance and compare their overall risk of dying from any cause and their risk of dying from breast cancer.All women had no previous risk of breast cancer and had retained both breasts and ovaries at the time BRCA1/2 gene mutation testing. The women were followed-up for approximately 9 to 11 years.
Study Findings
BRCA1 carriers- After follow-up there were 7 cases of breast cancer and 11 deaths (one due to breast cancer) among the BRCA1 mutations carriers who had BRRM.
- There were 269 breast cancer cases and 50 deaths (19 due to breast cancer) among BRCA1 carriers who opted for surveillance.
- At the age of 65, overall survival among BRCA1 mutation carriers was 90% in the BRRM group compared to 83% in the surveillance group.
- At the age of 65, breast cancer-specific survival was 99.6% in the BRRM group compared to 93% for the surveillance group.
BRCA2 Carriers
- There were no cases of breast cancer and two deaths (none due to breast cancer) in the BRRM group.
- There were 144 breast cancer cases and 32 deaths (seven due to breast cancer) in the surveillance group.
- At the age of 65, overall survival was 95% for the BRRM group compared to 88% for the surveillance group.
- At the age of 65, breast cancer-specific survival was 100% for the BRRM group compared to 98% for the surveillance group.
Dr Annette Heemskerk-Gerritsen, a post-doctoral researcher at the Erasmus University Medical Centre (Rotterdam, The Netherlands), said: "For BRCA1 mutation carriers, bilateral risk-reducing mastectomy not only drastically reduces the risk of developing breast cancer but, as a consequence, also improves breast cancer-specific survival when compared to surveillance. For BRCA2 mutation carriers, however, BRRM seems to lead to similar breast cancer-specific survival as surveillance, despite the reduced breast cancer risk."
References:
- Double mastectomy to prevent breast cancer reduces risk of dying from the disease - (https://www.ecco-org.eu/Global/News/EBCC/EBCC11/03/Double-mastectomy-to-prevent-breast-cancer-reduces-risk-of-dying-from-the-disease)