A study suggests women with an abnormal BRCA1 or BRCA2 gene have an 80% lower risk of ovarian cancer if they have both ovaries removed preventively.
The research was published online by the Journal of Clinical Oncology on Feb. 24, 2014. Read the abstract of “Impact of Oophorectomy on Cancer Incidence and Mortality in Women With a BRCA1 or BRCA2 Mutation.”
Everyone has BRCA1 (BReast CAncer gene one) and BRCA2 (BReast CAncer gene two) genes. The function of the BRCA genes is to repair cell damage and keep breast cells growing normally. But when these genes contain abnormalities or mutations that are passed from generation to generation, the genes don’t function normally and breast and ovarian cancer risk increase. Abnormal BRCA1 and BRCA2 genes may account for up to 10% of all breast cancers.
Women with a BRCA1 or BRCA2 genetic mutation:
- have up to a 72% lifetime risk of developing breast cancer
- have a much higher-than-average lifetime risk of ovarian cancer; estimates range from 17% to 44%
Women who know they have an abnormal BRCA1 or BRCA2 gene can take steps to reduce their risk. Removing the healthy breasts and ovaries -- called prophylactic surgery (“prophylactic” means “protective”) -- are very aggressive, irreversible risk-reduction options that some with an abnormal BRCA1 or BRCA2 gene choose. You probably heard about Angelina Jolie’s decision to have a preventive double mastectomy because she learned that she had an abnormal BRCA1 gene. While protective surgery may be a good option for a number of women, it’s not right for every woman.
While we know that preventively removing the ovaries can reduce the risks of breast and ovarian cancer and improve survival in women who may eventually be diagnosed, the best age to have the surgery hasn’t been clear.
In this study, the researchers wanted to see if they could determine the best age for women with an abnormal BRCA1 or BRCA2 gene to have preventive ovary removal surgery. They looked at the records of 5,783 women with an abnormal BRCA1 or BRCA2 gene who are part of an ongoing study. The women lived around the world, including the United States, Canada, France, Italy, and Poland.
The researchers looked to see how many of the women had protective surgery to remove their ovaries as well as when they had the surgery:
- 2,270 women didn’t have preventive ovary removal
- 2,123 women had already had preventive ovary removal when they study started
- 1,390 women had preventive ovary removal after the study started
The women who hadn’t had their ovaries removed were about 42 years old and the women who had their ovaries removed were about 50 years old.
In women who still had their ovaries, 98 of 108 ovarian cancers were diagnosed in women with an abnormal BRCA1 gene and 10 were diagnosed in women with an abnormal BRCA2 gene. Women with an abnormal BRCA1 gene were diagnosed most often between the ages of 50 and 59. Women with an abnormal BRCA2 gene were diagnosed most often between the ages of 60 and 69.
The records of the women who had their ovaries removed showed that 46 cancers were found during ovary removal. Doctors call cancers that are found by chance during another procedure “occult.” Of these occult cancers:
- 27 were classified as ovarian cancer
- 18 were classified as fallopian tube cancer
- 1 was classified as peritoneal cancer; the peritoneum is a thin layer of tissue that lines the inside wall of the abdomen and covers the uterus, bladder, and rectum
Women with an abnormal BRCA1 gene were diagnosed with 44 of the occult cancers:
- 3 were diagnosed in women 40 or younger; the youngest women was 34 when diagnosed
- 19 were diagnosed in women ages 40 to 49
Women with an abnormal BRCA2 gene were diagnosed with 2 of the occult cancers; both of the women were older than 60.
The researchers then analyzed the benefits of preventive ovary removal. They found that the protective surgery:
- reduced the risk of ovarian, fallopian tube, and peritoneal cancer by 80%
- reduced the risk of dying from any cause by 77%
- reduced the risk of dying from any cause by 68% in women who had been diagnosed with breast cancer
The researchers also said they felt that women with an abnormal BRCA1 gene should consider preventive ovary removal as soon as possible, but at least by age 35. This is different than current recommendations, which say that women should consider preventive ovary removal when they’re 35 to 40 years old and when they’re done having children. Other experts said the results of the study don’t support preventive ovary removal earlier than age 35 and felt the current recommendations were accurate.
If you know you have an abnormal breast cancer gene, especially an abnormal BRCA1 gene, you may be considering taking steps to keep your risks of 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 alcohol
- eating nutritious food
- never smoking
You also may be considering preventive ovary removal. This surgery can significantly reduce the risk of developing ovarian cancer -- and also reduce the risk of breast cancer when done before menopause -- but is a serious choice that can have a considerable effect on your life. The sudden loss of estrogen can cause a range of side effects, such as hot flashes, depression, difficulty sleeping, and lower sex drive. Estrogen loss may affect bone and heart health. Ovary removal also takes away your ability to have children.
Regardless of whether prophylactic ovary removal is involved, there are many factors to consider when deciding on a risk-reduction strategy. Take the time you need to talk to your doctor and family members about the different ways you can lower your risk.
For more information on BRCA1 and BRCA2 genes, as well as all the risk-lowering steps you can take if you have an abnormal version of one or both of these genes, visit the Breast Cancer Risk Factors: Genetics page in the Breastcancer.org Lower Your Risk section.
Editor’s Note: This article was updated on Jan. 22, 2019, with updated information on cancer risks associated with BRCA mutations.