Triple-negative breast cancer (TNBC) is an aggressive and less common form of breast cancer. Symptoms are similar to other forms of breast cancer, but there are fewer treatment options available.

Triple-negative breast cancer (TNBC) is a type of breast cancer that accounts for approximately 15–20% of all breast cancers.

Compared to other forms of breast cancer, TNBC is unique because people with this type of cancer have cancer cells that do not have receptors for two main hormones: progesterone and estrogen.

In addition, they do not have or produce excessive amounts of HER2 proteins, which is more prevalent in other forms of breast cancer.

If cells test negative for progesterone, estrogen, and HER2 proteins, a diagnosis of TNBC is made.

Symptoms of TNBC are similar to other forms of breast cancer and can include:

  • a new lump or mass on the breast
  • changes in the size, shape, or feel of your breast (e.g., pitting, swelling)
  • changes in skin texture (e.g., an “orange peel” texture, puckering, dimpling, bumps, or rash)
  • changes in skin color, such as redness or discoloration
  • nipple discharge that is not breastmilk
  • changes in the appearance or texture of one or both nipples
  • nipple retraction (the nipple goes inward) that is not usual for you
  • breast pain, warmth, itchiness, or irritation
  • swollen lymph nodes around the armpit or collarbone

The exact cause of TNBC has yet to be fully understood.

It is closely linked with specific mutations in the BRCA1 gene. BRCA1 functions as a tumor-suppressor gene by regulating cell growth. Inherited mutations in BRCA1 increase the risk of various cancers, including breast, ovarian, prostate, and others.

Researchers need to conduct further studies on this topic.

If you have any sudden changes in your breasts or experience new symptoms, it’s important to see a healthcare professional.

During your visit, your healthcare professional will review your medical history and perform a physical examination of your breasts. This is to check for any lumps, skin discoloration, texture changes, or other indicators of breast cancer.

They will also feel your lymph nodes located around your armpits and at the base of your neck. Likely, certain diagnostic tests will be requested, such as:

  • a mammogram and/or ultrasound
  • a biopsy of any unusual lumps or masses, which is usually tested for hormone and protein receptors (i.e., progesterone, estrogen, and HER2)
  • genetic tests, especially if there’s a family history of breast cancer (e.g., BRCA gene mutation)

Compared to other breast cancers, TNBC is considered more aggressive. It’s more likely to metastasize (spread) throughout the body, which can make it even more difficult to treat. This is why early detection is crucial.

A 2016 study found that, between the time of diagnosis and surgery, triple-negative breast cancer tumors grew by 1% each day. In comparison, HER2-positive breast cancer tumors grew by 0.859% each day.

While TNBC can happen to anyone, there are certain groups of people in which TNBC occurs at higher rates. In particular, those who are at the highest risk include:

  • Black or Hispanic women
  • those with a BRCA1 mutation and/or family history of TNBC
  • younger women (under the age of 40)

TNBC has fewer treatment options compared to other forms of breast cancer. This is largely due to the lack of hormone receptors that are needed to respond to hormone therapy or targeted HER2 medications.


With the above in mind, chemotherapy is the most common form of treatment.

The type of treatment you receive depends on:

  • where the tumor is located, its size, and stage (i.e., if the cancer is localized or has spread)
  • the grade or subtype
  • other factors such as overall health, age, and personal preferences


If the cancer is in its early stages, the tumor may be surgically removed. This can be done through breast-conserving surgery where only a portion of breast tissue, such as a lump, is removed (i.e., lumpectomy or partial mastectomy) or through whole breast removal, called mastectomy.

Neoadjuvant therapy

In some cases, chemotherapy may be recommended first to shrink the tumor (called neoadjuvant chemotherapy) before surgical removal and then again after surgery to prevent tumor regrowth.

The FDA approved an immunotherapy drug (Keytruda) for early stage and advanced TNBC, which would be prescribed along with chemotherapy.


Radiation may also be an option depending on the type of surgery and tumor.

Other options

If the cancer has metastasized, or spread, then other interventions may also be used, such as antibody-drug conjugate, platinum chemotherapy, immunotherapy, or targeted therapies like PARP inhibitors.

Ultimately, you and your healthcare team will determine the best form of treatment based on your unique case and circumstances.

Below are some commonly asked questions about TNBC.

Where does TNBC metastasis happen (where does it spread to)?

TNBC metastasis usually occurs in the brain, bone, liver, and lungs.

Can you cure TNBC?

Though TNBC can be treated, it may not be 100% curable since TNBC has a high recurrence rate.

What is the survival rate of TNBC?

According to a 2022 study, the current 5-year overall survival rate for TNBC (all stages) is 81%.

Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer that accounts for around 15–20% of breast cancer cases. It’s diagnosed by testing cancer cells and receiving negative tests for progesterone and estrogen receptors, as well as HER2 proteins.

Symptoms of TNBC are similar to other forms of breast cancer, such as a new and noticeable lump on the breast, skin texture and color changes, nipple discharge, and/or pain, itching, or discomfort.

While TNBC is more difficult to treat compared to other forms of breast cancer, it can be treated using chemotherapy, surgery, radiation, and other targeted treatments.

If you experience any symptoms of TNBC, notice sudden changes in your breasts, or have a family history of TNBC, speak with a healthcare professional. Early diagnosis is key to the best outcomes possible.