Breast Cancer (BRCA) Gene Mutations

BRCA gene mutations are harmful changes in the DNA sequence of certain genes that can significantly increase the risk of developing breast cancer and other cancers. The most well-known gene mutations associated with breast cancer affect breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2), both of which normally produce proteins to help repair DNA damage and suppress the growth of cancerous tumors. Mutations can interfere with the normal function of BRCA1 and BRCA2, leading to increased cancer risk. However, not everyone who has a BRCA gene mutation will develop cancer.

In addition to BRCA1 and BRCA2, other less common gene mutations associated with breast cancer affect the TP53, PALB2 and CHEK2 genes.

What types of cancer are linked to BRCA gene mutations?

BRCA gene mutations can significantly increase the risk of developing several types of cancer, including:

• Breast cancer in women – A BRCA1 or BRCA2 mutation can increase a woman’s lifetime risk of developing breast cancer to approximately 70%.
• Ovarian cancer in women – BRCA1 mutations, and to a lesser extent, BRCA2 mutations, are linked to an increased risk of ovarian cancer.
• Prostate cancer in men – BRCA2 mutations, and to a lesser extent, BRCA1 mutations, are linked to an increased risk of prostate cancer.
• Pancreatic cancer in men and women – BRCA1 and BRCA2 mutations are associated with an elevated risk of pancreatic cancer.
• Breast cancer in men – Although breast cancer is much less common in men than in women, a BRCA2 mutation can significantly increase the risk of male breast cancer.

BCRA gene mutations may also increase the risk of other cancers, such as melanoma in men and women, though the association is not well-established.

What causes BRCA gene mutations?

A BRCA gene mutation occurs when the DNA that makes up the gene is damaged. BRCA gene mutations are primarily inherited. Everyone has two copies of each gene, one from each parent. If one parent has a BRCA gene mutation, there is a 50% chance that the child will receive the mutated gene.

BRCA gene mutations can also occur spontaneously due to errors that occur when DNA is replicated during cell division. Additionally, DNA damage can result from exposure to ionizing radiation or harmful chemicals.

What are the risk factors for BRCA gene mutations?

The primary risk factors for BRCA gene mutations are:

• Family history of cancer – A strong family history of breast, ovarian or other BRCA-related cancers can significantly increase the likelihood of having a BRCA1 or BRCA2 mutation, especially if a close relative, such as a mother, sister or aunt, is diagnosed at a young age.
• Personal history of cancer – Individuals who were previously diagnosed with breast cancer, particularly at a young age or with a specific subtype, such as triple-negative breast cancer, are at a higher risk of carrying a BRCA gene mutation.

These uncontrollable factors, which contribute to the likelihood of carrying a BRCA gene mutation, may warrant genetic counseling and testing to assess the risk and guide preventative strategies.

What are the signs and symptoms of BRCA gene mutations?

BRCA gene mutations do not directly cause symptoms. Instead, they increase the risk of developing certain cancers, which may in turn cause symptoms, such as:

• Breast cancer – Symptoms can include a breast lump, a change in breast shape or size, breast skin dimpling and unusual nipple discharge.
• Ovarian cancer in women – Symptoms can include abdominal bloating, pelvic pain, changes in bowel habits and frequent urination.
• Prostate cancer in men – Symptoms can include difficulty urinating, blood in the urine and pelvic discomfort.

How are BRCA gene mutations diagnosed?

BRCA gene mutations are usually diagnosed through genetic testing, such as a lab test that analyzes the DNA in a blood or saliva sample to check for mutations in the BRCA1 and BRCA2 genes. This type of genetic testing may be recommended for an individual who has a strong family history of breast, ovarian or other BRCA-related cancers. Genetic counseling is usually provided before and after genetic testing to help the patient understand the potential benefits, risks and implications of the results.

How are BRCA gene mutations treated?

BRCA gene mutations cannot be treated. Instead, a physician may recommend various preventive and risk-reduction strategies to help the patient manage the associated increase in cancer risk, such as:

• Increased surveillance – Enhanced screening protocols, such as frequent breast imaging and pelvic exams, can help a physician detect cancer at an early stage.
• Preventive surgery – A prophylactic procedure, such as a mastectomy to remove the breast or a bilateral salpingo-oophorectomy to remove the ovaries and fallopian tubes, may be considered to significantly reduce the risk of breast or ovarian cancer.
• Chemoprevention – Certain chemo medications, such as tamoxifen and raloxifene, can lower the risk of breast cancer in women who have a BRCA gene mutation.
• Lifestyle modifications – Adopting positive lifestyle practices, such as consuming a nutritious diet, exercising regularly, maintaining a healthy body weight, avoiding tobacco use and limiting consumption of alcoholic beverages can help reduce overall cancer risk.

Benefit from world-class care at Moffitt Cancer Center

At Moffitt, a team of board-certified genetic counselors is available to meet with patients to assess their hereditary risk of cancer. By providing comprehensive information and individualized guidance, we empower our patients to make the right decisions for themselves regarding genetic testing.

If you would like to learn more about BRCA gene mutations, you can request an appointment with a specialist in Moffitt’s Genetic Counseling Clinic by calling 1-813-745-8123 or sending an email message to genehome@moffitt.org. We do not require referrals.