Breast Cancer Risk Remains High for Women With BRCA Mutations After Age 50
Women with a BRCA1 or BRCA2 mutation are more likely to develop breast cancer at a young age, but a study suggests that women with these mutations continue to have a higher-than-average risk of breast cancer after age 50.
The research was published in the March 15, 2023 issue of the journal Cancer. Read the abstract of “The risks of cancer in older women with BRCA pathogenic variants: How far have we come?”
About BRCA mutations
About 5% to 10% of breast cancers are thought to be hereditary, caused by mutations in certain genes passed from parent to child.
Two of the most well-known genes that can mutate and raise the risk of breast and ovarian cancer are BRCA1 and BRCA2. Women who inherit a mutation in either of these genes — from their mothers or fathers — have a much higher-than-average risk of developing breast cancer and ovarian cancer.
Doctors call genetic mutations that increase the risk of diseases pathogenic variants.
The average woman’s risk of developing breast cancer in her lifetime is about 13%. According to the National Cancer Institute (NCI), women with a BRCA1 mutation have between a 55% and 72% lifetime risk of developing breast cancer, and women with a BRCA2 mutation have between a 45% and 69% lifetime risk of developing breast cancer.
About the study
We know that a BRCA mutation increases the lifetime risk of breast cancer, but there is little research on how high that risk is when a woman is older. In this study, the researchers tried to find out.
The study included 2,211 women ages 50 to 75 from 16 countries. All the women knew they had a BRCA mutation:
1,470 women had a BRCA1 mutation
741 women had a BRCA2 mutation
None of the women had been diagnosed with cancer before age 50.
When they joined the study, the women filled out questionnaires about any breast cancer risk-reducing steps they had taken, such as:
taking medicine, such as tamoxifen, preventively
having their breasts, ovaries, and fallopian tubes preventively removed before any cancer developed (doctors call this prophylactic surgery)
starting breast cancer screening at a young age
having screening with techniques other than mammography, such as MRI or ultrasound
The questionnaires also asked about other breast cancer risk factors, including:
smoking
using hormone replacement therapy (HRT)
having a first-degree relative with breast or ovarian cancer (a first-degree relative is a parent, sibling, or child)
The women completed the same questionnaire every two years after joining the study. Average follow-up time was about nine years.
Among all the women in the study:
4% of the women with a BRCA1 mutation and 9.3% of the women with a BRCA2 mutation had taken medicine to reduce their risk of breast and ovarian cancer
14% of the women with a BRCA1 mutation and 18.2% of the women with a BRCA2 mutation had a preventive mastectomy before age 50
46.4% of the women with a BRCA1 mutation and 37.5% of the women with a BRCA2 mutation had their ovaries and fallopian tubes removed preventively before age 50
18.9% of the women with a BRCA1 mutation and 23.2% of the women with a BRCA2 mutation had two or more first-degree relatives who’d also been diagnosed with breast cancer
Overall, 333 cancers were diagnosed in the women when they were between the ages of 50 and 75. The two most common types of diagnosed cancers were breast and ovarian cancer:
186 were breast cancer
45 were ovarian cancer
The women’s risk of developing any type of cancer, except skin cancer, from ages 50 to 75 was 47%:
women with a BRCA1 mutation had a 49% risk of developing cancer
women with a BRCA2 mutation had a 43% risk of developing cancer
The women’s risk of developing breast cancer from ages 50 to 75 was:
32% for women with a BRCA1 mutation
25% for women with a BRCA2 mutation
The women’s risk of developing ovarian, fallopian, or peritoneal cancer (the peritoneum is the sheet of tissue that covers the organs in the abdominal cavity) from ages 50 to 75 was:
13% for women with a BRCA1 mutation
7% for women with a BRCA2 mutation
The researchers then calculated the risk of cancer in women who didn’t have preventive surgery or take medicine to reduce their risk. For these women, the risk of any cancer from ages 50 to 75 was 75%:
women with a BRCA1 mutation had a 77% risk of developing cancer
women with a BRCA2 mutation had a 67% risk of developing cancer
Among women who didn’t have preventive surgery or take medicine preventively, the risk of breast cancer from ages 50 to 75 was:
56% for women with a BRCA1 mutation
45% for women with a BRCA2 mutation
And the risk of ovarian, fallopian, or peritoneal cancer from ages 50 to 75 was:
35% for women with a BRCA1 mutation
28% for women with a BRCA2 mutation
Finally, the researchers calculated the risk of cancer in women who had both preventive mastectomy and preventive surgery to remove their ovaries and fallopian tubes. For these women, the risk of any cancer from ages 50 to 75 was 9%, and among them:
three cases of breast cancer were diagnosed in women with a BRCA1 mutation and two cases were diagnosed in women with a BRCA2 mutation
no cases of ovarian cancer were diagnosed
“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,” lead author Kelly Metcalfe, RN, PhD, professor of nursing at the University of Toronto, said in a statement. “Our analysis highlights the effectiveness of these risk reduction surgeries, and emphasizes the need for individuals as well as healthcare providers, to consider clinical guidelines and recommendations for their cancer risk, including how their genetics might impact them even at a later age.”
What this means for you
If you know you have a BRCA mutation, you may be considering taking steps to keep your risk of developing breast and ovarian cancer as low as they can be. There are many lifestyle choices you can make, including:
maintaining a healthy weight
exercising regularly
limiting or avoiding alcohol
eating nutritious food
never smoking or quitting if you do
You also may be considering taking medicine preventively or having risk-reducing surgery to remove your breasts, ovaries, and fallopian tubes. As this study shows, preventive surgery can dramatically reduce the risk of breast and ovarian cancer in women with a BRCA mutation.
Still, preventive surgery decisions require a great deal of thought, patience, and discussion with your doctors, genetic counselor, and family over time — along with a tremendous amount of courage. Take the time you need to consider these options, and make decisions that feel comfortable to you and are best for your unique situation.
Learn more about preventive mastectomy and preventive ovary removal.
Updated on May 25, 2023