Triple-negative breast cancer is a rare type of breast cancer. It is harder to treat and much more aggressive.

Because it is aggressive and rare, fewer treatment options are available. It also tends to have a higher rate of recurrence.

This form of cancer accounts for around 10–15% of all breast cancer diagnoses.

In this article, we look at the risk factors, diagnosis, and available treatments for triple-negative breast cancer.

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The term triple-negative breast cancer means that cancer cells do not have estrogen or progesterone receptors and do not produce large amounts of human epidermal growth factor receptor 2 (HER2).

When diagnosing cancer types, doctors will test for the presence of these receptors and protein production. If all three tests return negative results, a person has triple negative breast cancer.

Other types of breast cancer include:

  • estrogen receptor-positive
  • progesterone receptor-positive
  • HER2 receptor-positive

If cancer cells are positive for these receptors, doctors can target the cancer with hormonal treatments.

However, no targeted therapies are available for triple-negative breast cancer. It is also more likely than other types of breast cancer to spread and recur.

Researchers have identified the following risk factors for developing triple-negative breast cancer over other types.

Obesity and inactivity

Studies suggest that people with obesity and a higher body mass index (BMI) have a higher risk of developing triple-negative breast cancer. These categories tend to include those who are not very active.


A 2018 study identified several genes associated with a high risk of triple-negative breast cancer. In particular, around 70% of breast cancers in people with a BRCA gene mutation are triple-negative.


Individuals under 50 years of age have a higher risk of developing triple-negative breast cancer.


African American and Hispanic women are more susceptible to triple-negative breast cancer.


A small study from 2015 found that pregnancy-associated breast cancers affecting women up to 10 years after pregnancy were more likely to be triple-negative than those in women who had never had a pregnancy.

As with other types of breast cancer, a person may feel a small, hard bump on or near their breast. In other cases, a routine scan of the breasts may reveal an area of concern.

Upon detection of a growth, the doctor will collect tissue samples for assessment.

The results of these tests will highlight the type of breast cancer. A person whose cancer tests negative for the estrogen, progesterone, and HER2 receptors will receive a diagnosis of triple-negative breast cancer.

A doctor will then assign a stage to the cancer based on the findings of the biopsy and any follow-up scans. They calculate the stage based on tumor size and the spread, if any, of the cancer.

Here, learn more about how a biopsy works.

There are fewer treatment options for triple-negative breast cancer than for other types of breast cancer. Hormone therapies are not effective against triple-negative breast cancer, since it lacks estrogen and progesterone receptors.

However, several different treatments are available, and researchers are looking for additional medications to help treat and prevent this aggressive cancer.

Currently, treatment options for triple-negative breast cancer include:

Surgical options include the partial (lumpectomy) or full (mastectomy) removal of one or both breasts.

An important part of any treatment plan is remaining active and eating a variety of healthful foods. The side effects of cancer treatment can be difficult to manage, so maintaining a balanced diet, getting regular exercise, and resting can help improve how a person manages the adverse effects.

Find out all about chemotherapy here.

Researchers describe the outlook for cancer in 5-year survival rates. The prognosis for triple-negative breast cancer is worse than that for other types of breast cancer. The overall prognosis depends on the stage of the cancer at diagnosis.

Doctors may define a person’s cancer as:

  • Local: Cancer cells are present at a single site in the breast.
  • Regional: Cancer cells spread to other tissue within the breast.
  • Distant: Cancer cells have spread to other organs, glands, or tissues.

The American Cancer Society estimates relative 5-year survival rates to be:

Cancer stage at diagnosisRelative 5-year survival rate
All stages combined77%

However, survival and overall prognosis vary from person to person. Many factors can affect a person’s outlook following treatment, including:

  • when they discovered the cancer and started receiving medical treatment for it
  • the stage of the cancer and whether it has spread to other tissues and organs
  • how the cancer responds to treatment

Catching cancer in its earliest stages and undergoing effective treatment may help improve the prognosis.