A study suggests that women with an abnormal BRCA1 gene diagnosed with breast cancer are more likely to survive if they have their ovaries removed (oophorectomy). The procedure didn’t seem to improve survival in women with an abnormal BRCA2 gene.
The research was published online by JAMA Oncology. Read the abstract of “Effect of Oophorectomy on Survival After Breast Cancer in BRCA1 and BRCA2 Mutation Carriers.”
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 women with an abnormal BRCA1 or BRCA2 gene choose. You probably heard about Angelina Jolie’s decision to have a preventive double mastectomy and preventive ovary and fallopian tube removal 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 it’s been known that removing the ovaries reduces the risk of ovarian cancer as well as the risk of a second, new cancer in women with an abnormal BRCA1 or BRCA2 gene, it hasn’t been clear if the protective surgery improved survival in women who were diagnosed with breast cancer.
In the study, the researchers looked at the records of 676 women who had an abnormal BRCA1 or BRCA2 gene who had been diagnosed with stage I or stage II breast cancer between 1975 and 2008:
- 345 of the women had their ovaries removed after being diagnosed with breast cancer
- 331 kept both ovaries
The women were followed for 20 years after being diagnosed.
After 20 years, 77.4% of the women were alive. Overall, removing the ovaries reduced breast cancer deaths by 56%.
But this benefit was mostly seen in women with an abnormal BRCA1 gene: There were 62% fewer deaths from breast cancer in women with an abnormal BRCA1 gene who had their ovaries removed compared to women with an abnormal BRCA1 gene who didn’t have the procedure. This difference was significant, which means it was likely due the protective surgery and not just because of chance.
When the researchers looked at survival differences between women with an abnormal BRCA2 gene who had their ovaries removed and women with an abnormal BRCA2 gene who didn’t have the protective surgery, they found 43% fewer deaths from breast cancer among the women who had their ovaries removed. But this difference WASN’T significant, which means that it could have been due to chance and not because of the surgery. This is why the researchers concluded that women with an abnormal BRCA1 gene benefited more from having their ovaries removed than women with an abnormal BRCA2 gene.
As this study strongly suggests, women who have an abnormal BRCA1 gene who’ve been diagnosed with breast cancer have better survival if they have their ovaries removed. But the procedure also has risks. Premenopausal women go immediately into menopause, which increases the risk of osteoporosis, hot flashes/night sweats, vaginal dryness and irritation, and a lower sex drive.
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. 24, 2019, with updated information on cancer risk associated with BRCA mutations.