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 who have a genetic mutation in one of these genes have an increased risk of receiving a breast cancer diagnosis.

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

Keep reading to learn more about TNBC, the BRCA1 mutation, testing options, and treatment.

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 known as HER2.

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

Approximately 10–15% of all forms of breast cancer are TNBC. The cancer is fast-growing and quick to spread.

It is more common in:

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

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

BRCA1 is an acronym for BReast CAncer gene 1. Usually, this gene aids the suppression of cell growth.

Each person has two copies of the BRCA1 gene, one from their mother and one from their father.

BRCA1 makes a protein that suppresses the growth of tumors. It does this by stopping cells from growing too quickly and dividing at an out-of-control rate.

This gene also helps in the repair of damaged DNA. Damaged DNA may occur due to 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 their mother or father. If a parent carries a mutation in the BRCA1 gene, the child has a 50% chance of inheriting it. This is known as an inherited mutation.

Those who inherit a mutation have a higher risk of some cancers, including ovarian cancer. However, they have a significantly higher lifetime risk of developing breast cancer than the rest of the population.

In the United States, 13% of females will develop breast cancer in their lifetime. Among women with the BRCA1 mutation, 55–72% will develop breast cancer by the age of 70–80 years. About 70% of cases will be TNBC.

Genetic testing is available to check for the BRCA1 mutation, but this is not necessary for the general public.

The National Comprehensive Cancer Network recommends that certain groups of people undergo genetic testing. These include:

  • individuals with a blood relative with a known mutation
  • those with 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
  • those with certain disorders, including Fanconi anemia, Peutz-Jeghers syndrome, Li-Fraumeni syndrome, and Cowden’s syndrome

Before a person undergoes genetic testing for the BRCA1 mutation, they will have a risk assessment with a healthcare professional or a genetic counselor. During the assessment, they will discuss several factors, including:

  • whether any relatives have had cancer
  • what types of cancer relatives have had
  • the age of diagnosis for relatives with cancer

If the healthcare professional or genetic counselor suspects that a person has an increased chance of having the BRCA1 mutation, they will order genetic testing. Professionals do not recommend this testing for those aged below 18 years.

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

The treatment for TNBC typically consists of a combination of surgery, chemotherapy, and targeted drugs.

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

Stages 1–3

In the early stages of TNBC, a doctor may recommend surgery to remove the tumor. In some cases, they may also recommend radiation therapy or chemotherapy following surgery.

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

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 or cisplatin, for people who have the BRCA1 mutation and whose breast cancer is no longer responding to standard chemotherapy drugs.

In addition, a person may receive treatment with PARP inhibitors. These drugs work by inhibiting an enzyme called PARP, which fixes DNA in cancer cells, as well as healthy cells.

The PARP inhibitors interfere with this process, making it more difficult for a cancer cell to survive.

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

Genetic testing for the BRCA1 mutation is available. The treatment options for people with TNBC who have the BRCA1 mutation include surgery, chemotherapy, radiation therapy, and targeted drugs.