Memorial Answers: BRCA (BReast CAncer) Gene Mutations

Oncologist Pamela Tuli answers common questions she receives about the BRCA gene mutation

BRCA1 and BRCA2 are two genes that are important to fighting cancer. They are tumor suppressor genes. When they work normally, these genes help keep breast, ovarian, and other types of cells from growing and dividing too rapidly or in an uncontrolled way, according to the Centers for Disease Control and Prevention.

We know you may have questions related to how hereditary conditions impact the likelihood of cancer, and Memorial has answers.

What would a positive or negative BRCA mutation test result mean for someone?

A positive result means one is at increased risk of developing breast and ovarian cancer as well as other cancers. Knowing you are positive can allow altered screening to find cancer early and preventive measures to be taken to reduce one’s risk of developing cancer.

It is important to remember that not having a BRCA mutation does not mean you will not develop cancer. Only 5-10% of breast cancers are due to a hereditary condition.

Why do BRCA gene mutations cause problems?

Dr. Pamela Tuli: BRCA (BReast CAncer) genes encode for proteins that are essential for repair of DNA. When working properly, BRCA genes protect the body from developing cancer. When they are mutated, however, the body builds these proteins incorrectly, preventing them from repairing damaged DNA which can lead to cancer.

What are the risks of a BRCA mutation?

People with a BRCA mutation are at increased the risk of developing cancer, in particularly breast and ovarian cancer, and are more likely to develop cancer at a younger age.

It is estimated that 55-65% of women with BRCA1 mutation will develop breast cancer before age 70, and approximately 45% of women with BRCA2 mutation will develop breast cancer before age 70.

Breast cancer associated with BRCA1 mutation is more likely to be triple negative breast cancer, a type of breast cancer that is more aggressive and difficult to treat.

What common conditions are BRCA gene mutations involved in?

The most common cancers associated with BRCA mutations are breast and ovarian. However, BRCA mutation also increases the risk of male breast cancer, and cancers of the prostate and pancreas.

Can I have the BRCA gene mutation if my parents don’t?

For the most part, BRCA mutations are inherited from a parent. There could be a spontaneous BRCA mutation that occurs when the egg and sperm come together, but that would be very rare.

How common are these mutations?

An estimated 0.25% of the general population carries a mutated BRCA gene, or about one out of every 400 people. Certain ethnicities have a higher rate of BRCA mutations. For example, people of Ashkenazi Jewish descent have a 2.5% chance of carrying a BRCA mutation.

BRCA mutations account for only 5-10% of breast cancers, thus the majority of breast cancers are not associated with a hereditary syndrome. 1 in 8 women will develop breast cancer in her lifetime. It is important to remember that the most common risk factors for breast cancer are being a woman and increasing age.

What are the benefits and risks of genetic testing?

If your test is positive, there are steps that can be taken to lower your risk cancer.

• Hormonal medications such as tamoxifen, raloxifene or aromatase inhibitors can be prescribed to lower the risk of developing breast cancer
• Screening for breast cancer is started at an earlier age, 25, for women with known BRCA mutations. In addition to yearly mammograms, yearly MRI of breasts is also recommended for women with known BRCA mutations.
• One may consider preventive or prophylactic removal of breasts and/or ovaries
• If you do develop breast cancer, treatment may be tailored or altered based on your genetic information
• There are no proven screening tests for ovarian cancer, but you may consider regular pelvic exams, ovarian ultrasounds and possibly a blood test call CA -125 in attempt to find ovarian cancer early
• Men with BRCA mutations are at increased risk of prostate cancer and can talk to their doctor about starting prostate cancer screening between the ages of 40 and 50.
• Men with BRCA mutations should report any changes to their breast to their doctors immediately
• Knowing you are at increased risk of cancer due to a BRCA mutation you can implement lifestyle changes such as a diet rich in fruits and vegetables, regular exercise, maintaining a healthy weight and limit alcohol consumption to reduce the risk of developing cancer

If I have a mutated gene, what would it mean for my children’s health?

If you carry a BRCA mutation, each child will have a 50% risk of carrying the mutation as well. The cancers associated with BRCA mutations are mainly adult cancers, so they can wait until age 18 or when cancer screening would change to be tested. For women with BRCA mutations, cancer screening starts at age 25.

If I decide not to do genetic testing, what types of cancer screening tests are recommended to screen for breast and ovarian cancer?

Unfortunately, there is not good a screening test for ovarian cancer that will help find it at an early more treatable stage.

With regards to breast cancer screening, guidelines from various organizations have some variation, but I would recommend annual mammography starting at age 40.

If you are interested in genetic testing, please speak with your primary care provider to receive a referral for Memorial Cancer Center. If you do not have a primary care provider, please schedule your visit today – (228) 867-5000.