BRCA Testing: What is it? Should I get it?
In several families, cancer genes are passed down through generations just like an undesired heirloom. But thanks to well-advanced technology it's possible to identify these altered genes and offer patients different choices that not only stop cancer, but also stop the gene from being passed on as well.
The most commonly known genes that contribute to the development of cancer is BRCA mutation. The acronym “BRCA” stands for Breast (“BR”) and Cancer (“CA”). Each person has BRCA1 and BRCA2 genes which are tumour suppressor genes. Their function is to repair damaged cells. However, when these genes are mutated or altered, they are unable to carry out their function. Thus, causing damaged cells to multiply which eventually becomes a cancerous growth.
During a lifetime, a woman has 1 in 8 chance of developing breast cancer. However, if a person inherits an altered BRCA gene, then the risk increases to 30%-80%. It also increases the risk of developing ovarian, colon, pancreatic and thyroid cancers. Thus, it becomes necessary to carry out genetic testing so that you can take immediate steps to get rid of it.
Following are some common questions regarding genetic testing that people should discuss with their genetic counsellor:
What is BRCA testing?
A BRCA gene test is a blood test that looks for abnormalities in the BRCA1 and BRCA2 genes. If mutations in BRCA1 and BRCA2 genes are detected, then the individual is at higher risk of developing cancer. This test is not conducted to detect cancer instead it is done to detect changes in the genes. This test can take about three weeks to get the results.
Who should get tested?
About 5% of breast cancers and 10% to 15% of ovarian cancers are caused due to alterations in BRCA genes. So, there is no need for every person to undertake genetic testing. However, if you have a family history of cancer, then the risk of developing cancer increases. So, you should consult a genetic counsellor if you have one of the following:
- Two first-degree relatives who suffered from breast cancer and any one of them was diagnosed with cancer before the age of 50.
- Three or more first or second-degree relatives were diagnosed with breast cancer at any age.
- Both first and second-degree relatives suffered from breast or ovarian cancer.
- Your first-degree relatives have been diagnosed with cancer in both the breasts.
- Two or more relatives suffered from ovarian cancer.
- One relative who has diagnosed with both ovarian and breast cancer.
- Any male member of your family diagnosed with breast cancer
- You belong to a family of Ashkenazi Jewish descent.
A genetic counselor will also discuss with you the appropriateness of genetic testing, risks, test results limitations and possible benefits of the test. If the tests are positive, they can provide you support by offering medical and lifestyle decisions.
What does a positive test result mean?
A positive test result indicates that the individual has inherited dangerous mutations in BRCA1 and BRCA2 genes. Thus, increasing the individual’s risk of developing cancer. However, the test results do not indicate that the person will suffer from cancer. There are women who inherit harmful mutations in BRCA genes, but they never suffer from breast or ovarian cancer.
Still, these genetic testings can be very useful as it discloses information not only about the person being tested, but also about their relatives and their future generations. For instance, this test reveals that a person inherits defects in the BRCA genes. But if he or she doesn't develop cancer, even then there is a 50% chance that each of his or her siblings has inherited the mutation. There is also a 50% chance that his or her future generation will inherit these mutations.
What should you do if you get a positive result?
If you get a positive result, you should consult a genetic counselor who will help you comprehend your options that may also include a comprehensive cancer prevention measures such as:
- Examining your breasts at regular intervals.
- Every year you should have at least one mammogram and MRI, which means one test per 6 months.
- Undertaking preventive mastectomy.
- If possible, plan to have a child before the age of 30.
- Removing your ovaries after having children or after the age of 35.
- Doctors prescribe medications such as Tamoxifen or an estrogen receptor antagonist to prevent you from cancer.
What does a negative test result mean?
A negative test result can be more confusing than positive test result because the test results analysis depends on an individual’s family history.
If a close relative of an individual being tested carries dangerous mutations in BRCA1 and BRCA2 genes, then a negative result means that the person has not inherited any harmful mutations and cannot transfer it on to their future generations. If the person being tested has a family history of carrying harmful mutations, but no such evidence of harmful mutations is detected in the person’s first-degree relatives. Such negative results can be confusing and can lead to two possibilities:
- The person being tested has an unknown dangerous BRCA1 and BRCA2 mutations that are still not identified.
- The person being tested has a mutation in a gene that is different from BRCA genes which cannot be identified by the test used. This gene increases an individual’s risk of cancer.
Thus, it is always recommended to consult a genetic counsellor before and after the test is conducted.
How much is BRCA testing, and does insurance cover it?
There are different types of BRCA testing and, so the cost ranges from $475 to $4,000. Consult your genetic counselor to determine which type of test is best for you. These tests are covered by insurance, but it has to meet certain criterion.
Thus, these are a few questions which should be discussed by a person with their genetic counselor and also with their family members when they find out that they are BRCA gene mutation carriers.