A few years ago, when actress Angelina Jolie decided to undergo prophylactic double mastectomy, it increased awareness of genetic testing for hereditary forms of cancer. Recently, actress Christina Applegate revealed that she too has BRCA1 mutation, and has undergone double mastectomies and removal of her ovaries. This news has put genetic testing back in the limelight.
The BRCA1 and BRCA2 genes were discovered in the 1990s, and since then testing for a mutation in these genes has become increasingly available and cheaper. We all normally have BRCA1 and 2 genes which play a role in protecting us from developing cancer. Individuals with mutations in either of these genes have an increased risk of cancer, mainly breast and ovarian cancer.
Jolie was found to have BRCA1 gene mutation. This put her risk of developing breast cancer at 87% and of ovarian cancer at 50%. She then had prophylactic mastectomies to prevent breast cancer. Her case highlights the importance of knowing one’s family history (her mother had breast cancer at an early age) and learning one’s cancer risks in order to address them proactively.
How common are these mutations?
These gene mutations are not very common. Only a small percentage of women have BRCA1 or BRCA2 mutations. They are most commonly found in women of Eastern European Jewish descent. These mutations are estimated to cause only 5% of all breast cancers (90 to 95% of breast cancers are not due to this gene) and 10 to 15% of ovarian cancers.
Who should be tested for this gene? Guidelines have been developed to determine if a woman would be at high risk for BRCA1 or 2 mutations:
- A personal history of breast cancer diagnosed at a young age, breast cancer affecting both breasts, and both breast and ovarian cancers.
- A personal history of ovarian cancer, and a close relative with ovarian cancer or premenopausal breast cancer or both.
- A history of breast cancer at a young age in two or more close relatives, such as your parents, siblings and children.
- A male relative with breast cancer.
- A family member who has both breast and ovarian cancers.
- A family member with bilateral breast cancer.
- Two or more relatives with ovarian cancer.
- A relative with a known BRCA1 or BRCA2 mutation.
- Ashkenazi (Eastern European) Jewish ancestry, with a close relative who has breast or ovarian cancer.
Why is everybody not tested?
Even though it is a simple blood test, it is not something your doctor can automatically order. A woman should go through a process called genetic counseling, where the pros and cons of the test are discussed. The test is expensive, ranging from $500 to $3000, and may not be covered by insurance. If you test positive for a BRCA gene mutation, you may have feelings of anger or sadness, and concerns over possible insurance discrimination. Then you will have to make difficult decisions about preventive measures which will have long term effects. You may also suffer from anxiety and feeling of inevitability that you will develop cancer.
Test is positive, now what?
At this time you will have a discussion with your counselor and doctor to decide what measures you should take to reduce the risk of developing cancer. Some of the options are:
- Undergo preventive surgery (like Anjelina Jolie and Applegate). This reduces breast cancer risk by about 90 percent. Removal of the ovaries reduces breast cancer risk by 50 percent in premenopausal women, and it reduces ovarian cancer risk by more than 90 percent.
- More vigilant Screening /Surveillance – This means having tests to detect breast cancer early. This involves clinical breast exams every six months, and mammograms and magnetic resonance imaging (MRI) exams every year.
- Chemoprevention (medication to reduce risk of cancer) – Tamoxifen is a medication that reduces the risk of developing breast cancer in women with BRCA mutation.
This information is strictly an opinion of Dr Prakash, and is not intended to replace the advice of your doctor. Dr Chris Prakash is a contributing columnist for eParisExtra. He is a medical oncologist at Texas Oncology Paris. He is board certified in Internal Medicine, Oncology and Hematology. He lives in Paris, TX, and can be reached at 9037850031, or Sucharu.firstname.lastname@example.org