Triple-negative breast cancer (TNBC) is a rare type of breast cancer that doesn’t respond to the usual breast cancer therapies. But other treatments are available.

“Triple-negative” describes cancer cells that test negative for three types of receptors:

  • estrogen
  • progesterone
  • HER2

Because of its triple-negative status, TNBC doesn’t respond to treatments that target estrogen or progesterone receptors. It also doesn’t respond to HER2 cancer treatments such as trastuzumab (Herceptin).

But TNBC is sensitive to chemotherapy, which can shrink tumors so they’re easier to remove surgically.

About 12% of all breast cancer types are triple-negative. Most instances of TNBC are invasive ductal carcinoma, but ductal carcinoma in situ can also be triple-negative. The cell type, not the location, determines whether breast cancer is TNBC.

Black and Latinx people are more likely to develop TNBC than people of other ethnicities. A 2021 study found that Black women were 2.7 times more likely than white women to receive a TNBC diagnosis.

Many Black women don’t have access to the insurance or resources they need to manage this type of cancer. They may experience delays between diagnosis and treatment and challenges communicating with doctors.

People with mutations on their BRCA gene, especially on the BRCA1 gene, are also at risk for this type of breast cancer, as are those younger than age 50.

Chemotherapy

A common TNBC treatment strategy is to begin with chemotherapy, either alone or in combination with the immunotherapy drug pembrolizumab (Keytruda). This helps shrink tumors so they’re easier to remove with surgery. It can also shrink affected lymph nodes.

Neoadjuvant chemotherapy (chemotherapy that occurs before other treatments) can eliminate invasive breast cancer about 30% to 50% of the time.

Research has found that when chemo can eliminate TNBC, the 5-year event-free survival rate is 92% and the 10-year event-free survival rate is 87%. Event-free survival includes cancer recurrence and further complications.

Your doctor might prescribe an oral chemotherapy medication called capecitabine (Xeloda) if there’s still cancer in the surgically removed tissue. You might also take more pembrolizumab. Women with the BRCA mutation might take an antitumor drug called olaparib (Lynparza) for 1 year to reduce the chance of cancer reoccurring.

Surgery

Sometimes an early-stage TNBC tumor is small enough for treatment to begin with surgery. The surgeon will remove the tumor and check your lymph nodes.

Surgery might involve either a lumpectomy, which removes the tumor while preserving breast tissue, or a mastectomy, which removes the entire breast and nearby lymph nodes.

If your lymph nodes contain cancer, your doctor may recommend radiation treatment. Chemotherapy after surgery is called adjuvant chemotherapy and is done to reduce the chance of a cancer recurrence.

Radiation

Radiation treatment uses high energy radiation that destroys remaining breast cancer cells. There are two types of radiation treatment.

During external beam radiation, a machine outside your body will direct radiation to the target area.

For brachytherapy, or internal radiation, a healthcare professional will place radioactive material inside your body, next to the cancer site.

Immunotherapy

Immunotherapy works by boosting your immune system and teaching it to target cancer cells by controlling the action of protein checkpoints that turn your immune response on or off.

Pembrolizumab is an immunotherapy drug that targets an immune cell protein, PD-1. This protein usually stops immune cells from attacking. Pembrolizumab prevents PD-1 from blocking immune system cells so they can attack breast cancer cells. About 1 in 5 instances of TNBC have the PD-1 protein.

Clinical trials

Clinical trials are research studies using human volunteers. Trials are available for all stages of cancer.

If you’re part of a clinical trial, you might have advanced access to new treatments. By participating in a trial, you will also contribute to medical knowledge and progress in cancer treatments.

You can discuss the option of a clinical trial with your doctor. You can also find more information through the following online resources:

TNBC treatment can vary, depending on how much your cancer has progressed. Your care team will provide you with specifics based on your situation.

Possible treatment options by stage might include:

Stage 1

  • lumpectomy, partial mastectomy, or mastectomy
  • lymph node biopsy or dissection
  • radiation
  • breast reconstruction
  • chemotherapy

Stage 2

  • neoadjuvant chemotherapy
  • lumpectomy, partial mastectomy, or mastectomy
  • lymph node biopsy or dissection
  • adjuvant chemotherapy
  • radiation
  • breast reconstruction
  • immunotherapy before and after surgery

Stage 3

  • neoadjuvant chemotherapy
  • mastectomy
  • lymph node dissection
  • adjuvant chemotherapy
  • radiation
  • target drug olaparib for cancer with BRCA mutation
  • immunotherapy drug pembrolizumab before and after surgery

Advancements to personalize treatment for TNBC are still in their infancy.

This is mainly because few effective treatments — other than chemotherapy — exist, and because there are few prognostic (related to a person’s overall outcome, regardless of therapy) and predictive (related specifically to treatment outcomes) biomarkers.

The BRCA mutation may present an opportunity for a precision treatment approach. It occurs in about 20% to 30% of TNBC cancer instances and responds to treatment using poly (ADP-ribose) polymerase (PARP) inhibitors.

Using pembrolizumab to target PD-1 is another personalized approach for TNBC cancer cells with this protein.

Research is ongoing to determine whether the aggressive nature of TNBC in Black women is because of health issues such as obesity or because of molecularly distinct characteristics. This may lead to much-needed precision treatment approaches for Black women.

The NCI maintains a database called the Surveillance, Epidemiology, and End Results Program (SEER).

The SEER database tracks 5-year relative survival rates by grouping cancers into categories based on how far they’ve spread.

A relative survival rate is a comparison between a person with cancer and the overall population. For example, if you have breast cancer with a 90% 5-year relative survival rate, you’re 90% as likely to live for 5 years as a woman who doesn’t have cancer.

According to the American Cancer Society, the SEER 5-year relative survival rates for TNBC are:

  • localized (cancer is contained within the breast): 91%
  • regional (cancer is located in the breast and nearby lymph nodes and tissues): 65%
  • distant (cancer is located in distant areas like the liver, bones, or lungs): 12%
  • all stages combined: 77%

These percentages may be higher for women diagnosed now, since treatment methods improve over time.

Although TNBC is aggressive and doesn’t respond to the usual breast cancer therapies, it’s still treatable and may be curable in the early stages.

Black and Latinx women have higher rates of this type of cancer, and treatment may not be as effective for those populations.

Chemotherapy, surgery, radiation, and immunotherapy are some of the options that may be available for you to try.

Connecting with other people who share your experience, such as through a support group, can help.