People with BReast CAncer (BRCA) gene mutations have a significantly higher lifetime risk of developing breast cancer than the rest of the population.

There are two types of BRCA genes: BRCA1 and BRCA2. People with a mutation in one of these genes have an increased risk of developing breast cancer.

Those with the BRCA1 gene mutation are more likely to have triple-negative breast cancer (TNBC), a fast-growing and aggressive form of breast cancer.

A 2011 study of women with breast cancer found that 12% of those who did not have the BRCA1 mutation had TNBC, whereas 48% of those with the BRCA1 mutation had TNBC.

This article explains more about TNBC, the BRCA1 mutation, testing options, and treatment.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

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TNBC is a form of cancer in which the cancer cells have no estrogen receptors (ER) or progesterone receptors (PR). The cancer cells also do not make much of a protein called human epidermal growth factor receptor-2 (HER2).

As a result, the cells test negative for HER, ER, and PR — hence the name “triple-negative.”

According to the American Cancer Society, 10% to 15% of all breast cancers are TNBC. This cancer is fast-growing and quick to spread.

It is more common in:

  • people younger than 40 years old
  • those who have the BRCA1 mutation
  • Black people

Compared with other forms of breast cancer, TNBC is more likely to return, even with treatment.

Learn more about triple-negative breast cancer.

As the National Cancer Institute (NCI) explains, “BRCA1” is an acronym for “BReast CAncer gene 1.” Usually, this gene helps suppress cell growth. Each person has two copies of the BRCA1 gene — one from each parent.

BRCA1 makes a protein that suppresses tumor growth. It stops cells from growing too quickly and dividing at an out-of-control rate.

This gene also helps with the repair of damaged DNA. Damage may result from environmental agents or radiation therapy. By repairing damaged DNA, the BRCA1 gene helps a cell maintain the genetic information it needs.

Some people may inherit a mutation in the BRCA1 gene from a parent. If a parent carries a mutation in the BRCA1 gene, the child has a 50% chance of inheriting it. This is called an inherited mutation.

People who inherit a mutation have a higher risk of some cancers, including ovarian cancer. They also have a significantly higher lifetime risk of developing breast cancer than the rest of the population.

According to the NCI, around 13% of females in the United States will develop breast cancer. Among females with the BRCA1 mutation, 55% to 72% will develop breast cancer by 70 to 80 years of age. And 10% to 15% of breast cancer cases will be TNBC.

Learn more about the BRCA gene.

According to the Centers for Disease Control and Prevention (CDC), 1 in 40 women of Ashkenazi Jewish descent have a BRCA gene mutation. This can increase their risk of developing breast cancer.

If the following factors are present, a person may have a higher predisposition to having a genetic variant:

  • breast cancer before 50 years of age
  • breast cancer more than once
  • male breast cancer
  • TNBC
  • breast and ovarian cancer
  • ovarian cancer
  • fallopian tube cancer
  • primary peritoneal cancer
  • several relatives with breast cancer
  • a male relative with breast cancer
  • a relative who has or had:
    • ovarian cancer
    • cancer affecting both breasts
    • breast cancer before the age of 55 years
    • breast and ovarian cancer
    • a BRCA gene mutation

Anyone with these risk factors can speak with a healthcare professional about testing to see whether they have the gene mutation.

Genetic testing is available to check for the BRCA1 and BRCA2 mutations. However, according to the NCI, most experts recommend testing only for people who have certain risk factors.

Additionally, professionals do not recommend this testing for those who are less than 18 years old.

The National Comprehensive Cancer Network recommends that people undergo genetic testing if they have:

  • a blood relative with a known mutation
  • specific family histories of cancer, including:
    • relatives who have had two or more cancers
    • relatives who received a cancer diagnosis at a young age
    • multiple types of cancer in the family
  • certain disorders that predispose them to cancer, including:
    • Fanconi anemia
    • Peutz-Jeghers syndrome
    • Li-Fraumeni syndrome
    • Cowden’s syndrome

Preparation and procedure

Before a person undergoes genetic testing for the BRCA1 mutation, a healthcare professional or a genetic counselor will carry out a risk assessment. They will discuss several factors, including:

  • whether any of the person’s relatives have had cancer
  • what types of cancer those relatives have had
  • the age of diagnosis for any relatives with cancer

If a healthcare professional or genetic counselor suspects that a person has an increased risk of having the BRCA1 mutation, they will order genetic testing.

Testing involves taking a sample of either saliva or blood. The cells in both blood and saliva contain the BRCA1 gene.

The treatment for TNBC typically involves chemotherapy. However, people may also undergo surgery and receive targeted drugs.

The type of treatment will depend on the stage of cancer.

Stages 1 to 3

In the early stages of TNBC, a doctor may recommend a lumpectomy, which is surgery to remove the tumor. A person who has a lumpectomy will also need radiation therapy.

A doctor may also recommend radiation therapy or chemotherapy after surgery if the tumor is large or if the cancer has spread to the lymph nodes.

If a person has TNBC, they will almost always need chemotherapy, regardless of the size of the tumor.

For those with the BRCA1 mutation, a doctor may prescribe a targeted drug called olaparib (Lynparza) for 1 year after chemotherapy.

Stage 4

A doctor will typically recommend standard chemotherapy first if cancer has spread to other areas of the body.

However, they may recommend other chemo drugs, such as carboplatin (Paraplatin) or cisplatin, for people with the BRCA1 mutation and breast cancer that is no longer responding to standard chemotherapy drugs.

In addition, a person may receive treatment with PARP inhibitors. These drugs inhibit an enzyme called PARP, which fixes DNA in cancerous and healthy cells. By interfering with that process, PARP inhibitors make it more difficult for cancer cells to survive.

All females have the BRCA1 and BRCA2 genes, but only some people inherit mutations of these genes, which increase the risk of breast cancer and some other types of cancer.

People with risk factors for BRCA gene mutations should speak with a healthcare professional about testing.

People should also contact a doctor if they experience any symptoms of TNBC, including:

Learn the signs of breast cancer.

TNBC is a fast-growing, aggressive form of breast cancer that is more common in people with the BRCA1 mutation.

Genetic testing for the BRCA1 mutation is available. People with certain risk factors, including females who are of Ashkenazi Jewish descent or have family members with the gene mutation, may qualify for testing.

The treatment options for TNBC in people who have the BRCA1 mutation may include surgery, chemotherapy, radiation therapy, and targeted drugs.