Actress and humanitarian Angelina Jolie has focused attention on genetic testing for breast and ovarian cancer after a personal op-ed revealed she carries an abnormal BRCA1 gene and underwent a preventive double mastectomy.
In normal cells, BRCA1 and BRCA2 genes prevent the development of tumors. But mutations in the genes can lead to breast, ovarian and other cancers such as uterine cancer and pancreatic cancer. Mutations to BRCA1 and BRCA2 genes are inherited the same as hair and eye color.
Jolie’s mother died at age 56 after a 10-year battle with ovarian cancer. After being tested, which requires a blood sample, Jolie learned that she had an 87 percent risk of breast cancer and a 50 percent risk of ovarian cancer.
In her op-ed in The New York Times, Jolie said she decided to write about having a double mastectomy in hopes of helping other women. “I want to encourage every woman, especially if you have a family history of breast or ovarian cancer, to seek out the information and medical experts who can help you through this aspect of your life, and to make your own informed choices,” she wrote.
Women with a BRCA1 or BRCA2 mutation have a 60 percent risk of developing breast cancer sometime during their lives and 15-40 percent risk of developing ovarian cancer. BRCA1 and BRCA2 mutations are responsible for most hereditary breast and ovarian cancers. But only 3-5 percent of women with breast cancer and 10-15 percent of women with ovarian have a BRCA1 or BRCA2 mutation. Other factors, such as age and obesity, also contribute to the risk of developing breast and ovarian cancer.
Families in which multiple members have had breast cancer or both breast and ovarian cancer are most likely to have a BRCA1 or BRCA2 mutation associated with those cancers. But not every women in these families carries the mutation and not every cancer in these families is linked to BRCA1 and BRCA2 mutations.
Those who carry an abnormal BRCA1 or BRCA2 gene have a few options:
- Surveillance: Screening for breast cancer includes mammography and clinical breast exams and for ovarian cancer includes transvaginal ultrasound, blood tests and clinical exams. Surveillance through screening as a form of surveillance can lead to early detection.
- Prophylactic surgery: Jolie opted for this option and had a double mastectomy to remove “at-risk” tissue and reduce the chance of developing cancer. Removal of fallopian tubes and ovaries would address the risk of ovarian cancer. These preventive measures do not guarantee that cancer will not develop.
- Chemoprevention: Medicines, vitamins or other agents are taken to prevent or delay the development of cancer. Tamoxifen is the most well-known drug option and the first with FDA approval as a chemopreventive measure. Studies have shown that tamoxifen reduces a high-risk woman’s chance of breast cancer by as much as half.