Triple-negative Breast Cancer

Triple-negative breast cancer (TNBC) is a type of invasive breast cancer in which the cancer cells don’t have estrogen receptors, progesterone receptors, or too much of the HER2 protein. That is, the cells test "negative" on all 3 tests.

TNBC tends to grow and spread faster than most other types of invasive breast cancer. It also has fewer treatment options.

How common is triple-negative breast cancer?  

TNBC accounts for about 10% to 15% of all breast cancers. These cancers tend to be more common in women who:

• Have not gone through menopause
• Are African American
• Have an inherited BRCA1 gene mutation

Signs and symptoms of triple-negative breast cancer

TNBC can have the same signs and symptoms as other common types of breast cancer.

How is triple-negative breast cancer diagnosed?

Like other breast cancers, TNBC might be found because of symptoms it’s causing, or it might first be seen on a screening mammogram.

Once a diagnosis of breast cancer has been confirmed on a breast biopsy, the cancer cells will be checked in the lab for estrogen receptors (ER), progesterone receptors (PR), and the HER2 protein. The cancer is TNBC if it tests negative on all three tests – that is, if the cancer is ER-negative, PR-negative, and HER2-negative.

Treating triple-negative breast cancer

TNBC tends to have fewer treatment options than other types of invasive breast cancer, especially if the cancer is more advanced. This is because the cancer cells don’t have ER or PR, which are needed for hormone therapy to work, or enough of the HER2 protein to make HER2-targeted drugs work.

For earlier-stage TNBC, surgery is often the main option, sometimes along with radiation therapy.

Chemotherapy is often recommended after surgery to reduce the chances of the cancer coming back.

For larger tumors, chemotherapy might be given first to shrink the tumor before surgery.

If the cancer has spread to other parts of the body, chemotherapy, certain targeted drugs, and immunotherapy might be options.

Survival rates for triple-negative breast cancer

Survival rates are a way to measure how many people survive a certain type of cancer over time. They cannot tell you exactly what will happen with any one person, but they might help give you a better understanding of how likely it is that treatment will be successful.

What is a 5-year relative survival rate?

A relative survival rate compares people with the same type and stage of breast cancer to people in the overall population.

For example, if the 5-year relative survival rate for a specific stage of breast cancer is 90%, it means that people who have that cancer are, on average, about 90% as likely as people who don’t have that cancer to live for at least 5 years after being diagnosed.

Where do these numbers come from?

The American Cancer Society relies on information from the Surveillance, Epidemiology, and End Results Program (SEER) database, maintained by the National Cancer Institute (NCI), to provide survival statistics for different types of cancer.

The SEER database tracks 5-year relative survival rates for breast cancer in the United States, based on how far the cancer has spread. The SEER database, however, does not group cancers by AJCC TNM stages (stage I, stage II, stage III, etc.). Instead, it groups cancers into localized, regional, and distant stages.

• Localized: There is no sign that the cancer has spread outside the breast.
• Regional: The cancer has spread outside the breast to nearby structures or lymph nodes.
• Distant: The cancer has spread to distant parts of the body such as the lungs, liver, or bones.

5-year relative survival rates for triple-negative breast cancer

TNBC tends to grow quickly, is more likely to have spread at the time it’s found, and typically has fewer treatment options than most other types of breast cancer. Because of this, the survival rates for TNBC are generally not quite as high as they are for other types of breast cancer.

These numbers are based on women diagnosed with TNBC between 2015 and 2021.

SEER Stage	5-year Relative Survival Rate
Localized	92%
Regional	67%
Distant	15%
All stages combined	78%

 

Understanding the numbers

Women now being diagnosed with TNBC probably have a better outlook than these numbers show. Treatments have improved over time, and these numbers are based on women who were diagnosed and treated at least 5 years earlier.

These numbers apply only to the stage of the cancer when it is first diagnosed. They do not apply later on if the cancer grows, spreads, or comes back after treatment.

These numbers don’t take everything into account. Survival rates are grouped based on how far the cancer has spread, but your age and overall health, how well the cancer responds to treatment, and other factors can also affect your outlook.

Keep in mind that survival rates are estimates, and they can’t predict what will happen in any person’s case. These statistics can be confusing and might lead you to have more questions. Ask your doctor how these numbers might apply to you.