The BRCA gene test is a blood test that uses DNA analysis to identify harmful changes (mutations) in either one of the two breast cancer susceptibility genes — BRCA1 and BRCA2.
Women who have inherited mutations in these genes are at an increased risk of developing breast cancer and ovarian cancer compared with the general population.
The BRCA gene test is offered only to people who are likely to have an inherited mutation based on personal or family history, or who have a specific type of breast cancer.
The BRCA gene test isn’t routinely performed on women at average risk of breast and ovarian cancers.
A BRCA gene test determines whether you carry an inherited BRCA mutation. If you do, your result is positive and your doctor can help you understand your cancer risk. If you don’t have a mutation, this is considered a negative result.
WHAT IS BREAST CANCER?
As in all forms of cancer, breast cancer is made of abnormal cells that have grown uncontrollably. Those cells may also travel to places in your body where they aren’t normally found. When that happens, the cancer is called metastatic.
Breast cancer usually begins in a small, confined area or glands, which produce milk (lobular carcinoma) or the ducts (ductal carcinoma), which carry it to the nipple. It can grow larger in the breast and spread through channels to nearby lymph nodes or through your bloodstream to other organs. Cancer may grow and invade tissue around the breast, such as the skin or chest wall.
Different types of breast cancer grow and spread at different rates — some take years to spread beyond the breast, while others grow and spread quickly.
WHO GETS BREAST CANCER?
Men can get breast cancer, too, but they account for less than 1% of all breast cancer cases. Among women, breast cancer is the most second most common cancer diagnosed in women after skin cancer and the second leading cause of cancer deaths after lung cancer.
On average, 1 in 8 women will develop breast cancer in her lifetime. About two-thirds of women with breast cancer are 55 or older. Most of the rest are between 35 and 54.
BREAST CANCER SYMPTOMS AND WARNING SIGNS
In its early stages, breast cancer usually has no symptoms. As a tumor grows, you may notice these signs:
1. Lump in your breast or underarm
2. Swelling in the armpit, collarbone, or breast
3. Pain or tenderness in your breast
4. A flat or indented area on your breast
5. Breast changes
6. A change in your nipple
- Pull inward
- Get dimpled
- Develop sores
- Nipple discharge
HOW IS BREAST CANCER DIAGNOSED?
If you feel a lump or something shows up on a mammogram, your doctor will begin the breast cancer diagnosis process.
The doctor will ask questions about your personal and family health history. Then they’ll do a breast exam and possibly order tests that include:
Imaging tests: Your doctor will use these to create an image of your breast:
Ultrasound. This test uses sound waves to make a picture of your breast.
Mammogram. This detailed X-ray of the breast gives doctors a better view of lumps and other problems.
Magnetic resonance imaging (MRI). This body scan uses a magnet linked to a computer to create detailed images of the insides of your breasts.
Biopsy. For this test, the doctor removes tissue or fluid from your breast.
BRCA1 AND BRCA2 GENE MUTATIONS AND BREAST CANCER RISK
Most women who get breast cancer do not have an inherited gene mutation.
About 5-10 percent of breast cancers are linked to an inherited gene mutation. About half of these are linked to a BRCA1 or BRCA2 gene mutation.
People with a BRCA1/2 mutation have a greatly increased risk of breast cancer and (for women) ovarian cancer.
WHO SHOULD CONSIDER TESTING?
BRCA1/2 testing is only recommended for certain people with a high risk of having a BRCA1/2 gene mutation, including those with:
- A family member with a BRCA1/2gene mutation (or other inherited gene mutation linked to breast cancer)
- A personal history of breast cancer at age 45 or younger
- A personal history of bilateral breast cancer (cancer in both breasts)
- A personal history of triple negative breast cancer (breast cancer that is estrogen receptor-negative, progesterone receptor-negative and HER2-negative diagnosed at age 60 or younger
- A personal history of breast cancer at age 46-50 and a close family member (parent, sibling, child, grandparent, grandchild, uncle, aunt, nephew, niece or first cousin) diagnosed with breast cancer or aggressive prostate cancer at any age
- A personal history of breast cancer at any age and a close family member diagnosed with breast cancer at age 50 or younger
- A personal history of breast cancer at any age and 2 or more close family members diagnosed with breast cancer at any age
- A personal history of breast cancer at any age and a close family member diagnosed with pancreatic cancer or metastatic prostate cancer at any age
- A close family member diagnosed with breast cancer at age 45 or younger
- A personal or family history of ovarian cancer, pancreatic cancer, aggressive prostate cancer or metastatic prostate cancer
- A personal or family history of male breast cancer
There is only a very small chance your family carries a BRCA1/2 mutation if you or a family member is the only person in your family with breast cancer and the breast cancer occurred at an older age.
In most cases, genetic testing is not recommended when there is a low chance of finding a mutation.
Most breast cancers are not due to a BRCA1/2 or other inherited gene mutation linked to breast cancer.
OTHER GENE MUTATIONS THAT INCREASE BREAST CANCER RISK
About half of all breast cancers due to an inherited gene mutation are caused by a BRCA1 or BRCA2 gene mutation.
In addition to BRCA1/2 mutations, inherited mutations in these genes can increase the risk of breast cancer:
ATM, BARD1, CDH1, CHEK2, NBN, NF1, PALB2, PTEN, RAD51D, STK11, TP53 (p53)
Most of these gene mutations also increase the risk of other cancers.
These high-risk gene mutations are less common than BRCA1/2 mutations and there’s still much to learn about them. Most don’t increase the risk of breast cancer as much as BRCA1/2 mutations do.
Some of these high-risk gene mutations have only recently been shown to increase the risk of breast cancer. Data on these mutations and their cancer risks are still limited.
HOW TO PREPARE?
- The first step in the BRCA gene testing process is to meet with a genetic counselor. As soon as you consider having any genetic test, meet with a genetic counselor to determine whether it’s appropriate for you and to discuss the potential risks, limitations, and benefits of undergoing genetic testing.
- The genetic counselor takes a detailed family and medical history, assesses your risk of developing cancer, discusses risks and benefits of genetic testing, and outlines your options.
- To prepare for your meeting with a genetic counselor:
Gather information about your family’s medical history, especially that of close relatives.
Document your personal medical history, including collecting records from specialists or results of previous genetic testing, if available.
Write down questions for the counselor.
Consider having a friend or family member accompany you to help ask questions or take notes.
- Proceeding with genetic testing after you meet with a genetic counselor is up to you.
- If you decide to proceed with the BRCA genetic test, prepare yourself for the emotional and social implications that learning your genetic status might have. Test results could also fail to provide you with clear-cut answers regarding your cancer risk, so prepare to face that possibility, too.
WHAT ARE THE POTENTIAL PROBLEMS WITH GENETIC TESTING?
Genetic testing is not 100% accurate. If a test is negative, a person still has a chance of developing breast cancer. If the test is positive, there is still a 15% to 20% chance of not developing breast cancer.
Genetic testing is costly, ranging from about $400 to more than $3,000, depending on the type of test. Insurance policies vary in providing coverage for genetic testing.
The results of genetic tests won’t be available for several weeks. The length of time it takes to get results depends on the tests performed and under what circumstances they are done.
Genetic testing is highly controversial in society today. Legislation has been enacted to protect individuals who may have a documented genetic risk of developing cancer from employment and/or insurance problems. The best course of action a person can take is to become involved with an established genetic registry that can counsel individuals with a genetic risk for cancer.
WHAT ARE THE BENEFITS OF GENETIC TESTING?
For some women, the benefits of genetic testing include the ability to make informed medical and lifestyle decisions while reducing the anxiety of not knowing their genetic background. Another benefit is the ability to make a proactive decision regarding prophylactic surgery. In addition, many women are able to participate in medical research that may, in the long run, decrease their risk of death from breast cancer.