On May 14th 2013, Hollywood actress Angelina Jolie revealed she had preventive double mastectomy because of a gene defect she inherited from her mother who died of breast and ovarian cancer. Just thirteen days later, Angelina Jolie’s maternal aunt (her mom’s younger sister) dies of breast cancer. It turned out that Angelina Jolie’s maternal grandmother had also died of ovarian cancer. All these women succumbed to their fatal cancers while they were only in their 50s.
The National Cancer Institute estimates that more than 190,000 women will be diagnosed with breast cancer annually. If you are a woman and you are getting older, you are at risk of developing breast cancer. Unfortunately we cannot control our gender or aging. However, there are modifiable risk factors related to lifestyle (Please see my earlier articles in Voicebowl on Breast Health Modifiable Risk Factors and Assessing Risk for Breast Cancer) that we can work on and lower our risk of developing breast cancer.
There is yet another unique category of breast cancer, called Hereditary Breast Cancer, for which the risk factor is family history – yet another factor we cannot modify. About 10-15% of breast cancers are passed on from a parent/family member. They are the kind that actress Angelina Jolie carried the gene mutation for, from maternal side of her family and took preventive measures for it not to affect her life.
There are two important distinctions to be aware of, under hereditary breast cancers – Family history with no known genetic changes and ones with known gene changes (mutations).
Having a family history of breast cancer:
Women who have close blood relatives with breast cancer have a higher risk, although no known gene changes may be identifiable in those families:
- Having a first-degree relative (mother, sister, or daughter) with breast cancer almost doubles a woman’s risk. Having 2 first-degree relatives increases her risk about 3-fold.
- Women with a father or brother who has had breast cancer also have a higher risk of breast cancer.
Inheriting gene mutations:
Changes in certain gene structures called mutations may increase risk of breast cancer. Most well known and most commonly inherited of these mutations occur in the BRCA 1 and BRCA 2 genes. There are other rare mutations that can be responsible for breast cancer, in some families. Most of those rare mutations do not increase the risk of breast cancer as much as the BRCA 1 and BRCA 2 gene changes do.
What are BRCA 1 and BRCA 2 Genes And What Do They Do?
BRCA 1 and BRCA 2 genes are responsible for repairing our DNA (basic back bone of our genes) when they get damaged. A simple example would be sunburn after a long day at the beach. As we know sun-rays can lead to DNA damage but our body has genes that make proteins to repair this damage. BRCA 1 and BRCA 2 are DNA repair genes. If a person inherits mutations in these genes, the DNA in our cells cannot be effectively repaired from ongoing damages, leading to cancer.
How Does BRCA 1 and BRCA 2 Gene Mutation Affect a Woman?
A woman with inherited BRCA 1 and/or BRCA 2 mutation has a 7 in 10 chance of getting breast cancer in her lifetime. They are at a higher risk of developing cancer in both breasts and that also at a much younger age than non-inherited cancers. These mutations also increase risk of ovarian cancer in women, called Hereditary Breast and Ovarian Cancer Syndrome (Prostate and breast cancers in men).
Genetic Counseling:
A woman may be a candidate for genetic counseling followed by genetic testing if they have any of the following criteria:
- Women with strong family history of breast cancer (having a mother, sister or daughter with breast cancer)
- Personal history or diagnosis of breast cancer at a young age
- Breast cancer involving both breasts
- Family history of breast and other cancers (pancreatic, ovarian, prostate)
- Multiple family members affected with cancer
- Younger age at diagnosis of cancer/s
Assessing Risk for Breast Cancer:
Your healthcare provider can help you assess your risk of developing breast cancer (Also see Voicebowl article on Risk Assessment). Remember assessment tools are not perfect but based on your history, physical exam and risk factors, you may be advised to see a genetic counselor.
Genetic Counseling and Its Implications:
A genetic counselor will draw a family tree and assess your family history in detail. Based on their findings, they can suggest genetic testing or otherwise. There are pros and cons of genetic testing, limitations of genetic testing (what it can and cannot tell, inconclusive results etc.), burden of knowing what future carries for you and cost (testing my not be or only partially covered by a health insurance plan). Some women choose not to know and deal with it if and when cancer strikes, while some decide to go ahead with testing. Once testing is complete, genetic counselor will review the results and their implications with you. Based on the results and their seriousness, a woman may choose to undergo preventive surgery (removal of both breasts and ovaries) or decide to maintain close surveillance (wait and watch policy with regular physical exams and mammograms/imaging). There is no cookie cutter answer to these dilemmas and every woman has to look at her circumstances and decide what works best for her situation.
Recommendations:
Hereditary cancer means cancer runs in your family, and could be caused by a change in certain genes that you inherited from your parent/s. You can start by talking to your parents about their health history and getting information about any particular cancers that run in your family. While some cancers may run in your family, it is important to understand that inheriting a mutated gene means inheriting an increased likelihood of developing a cancer, but not the cancer itself. Not all women who carry mutations in their genes will eventually develop breast cancer. Keep up with regular physical exams and mammograms to detect any changes at an early stage. And as with most medical conditions, maintaining a healthy lifestyle goes a long way to help keep modifiable risk factors at bay.
Remember to breathe, reduce stress and enjoy nature in your plate and on your daily walks!
