Triple Negative Breast Cancer (TNBC)

Triple-negative breast cancer (TNBC) is a rare, aggressive type of invasive breast cancer that makes up 10% to 15% of all breast cancer cases. TNBC is challenging to treat because the cancer cells don’t have hormone receptors or HER2 proteins that are commonly found in other types of breast cancer cells. That means medications that target these receptors and proteins don’t work as well for people with TNBC.

UPMC experts offer some of the most advanced treatment options for TNBC, including surgery, radiation therapy, chemotherapy, immunotherapy, and certain targeted therapies. Our experts also participate in national, multicenter clinical trials that study promising treatments for TNBC.

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On this page

• What Is TNBC?
• What Are the Symptoms of TNBC?
• How Do You Diagnose TNBC?
• How Do You Treat TNBC?

What Is TNBC?

Triple-negative breast cancer (TNBC) is a rare, aggressive type of invasive breast cancer that makes up 15% of all breast cancer cases. TNBC is challenging to treat because the cancer cells don’t have hormone receptors or HER2 proteins that are commonly found in other types of breast cancer cells. That means medications that target these receptors and proteins don’t work as well for people with TNBC.

What are the stages of TNBC?

Like other types of breast cancer, doctors use a standard system to determine the stage of TNBC.

Stages include:

• Stage 0 — The cancer is noninvasive.
• Stage I — Cancer cells have appeared in a duct or lobule and have invaded nearby tissue but have not spread beyond the breast.
• Stage II — The tumor is between .75 inch and 2 inches (2 cm to 5 cm) and may have spread to lymph nodes under the arm. Or the tumor is larger than 2 inches (5 cm) but has not spread to the lymph nodes under the arm.
• Stage IIIA — The tumor has spread to lymph nodes behind the breastbone but has not grown into the chest or skin.
• Stage IIIB — The cancer has spread to the chest wall or breast skin and may have spread to the lymph nodes.
• Stage IIIC — The cancer has spread to the chest wall or breast skin, has spread to the lymph nodes above or below the collarbone, axillary (armpit) nodes, or breastbone.
• Stage IV (metastatic)— The cancer cells have spread beyond the breast to other organs.

How common is TNBC?

According to the American Cancer Society, TNBC makes up 10% to 15% of all breast cancer cases.

What causes TNBC?

Researchers are unsure what causes TNBC. However, it may be linked to BRCA1 and BRCA2 gene mutations, which increase breast cancer risk.

What are TNBC risk factors and complications?

TNBC risk factors

You may be at increased risk of developing TNBC if you:

• Are Black or Hispanic.
• Are younger than 40.
• Have the BRCA1 or BRCA2 gene mutation.

Complications of TNBC

TNBC does not respond as well to typical breast cancer medications and may be more challenging to treat than other types of breast cancer. Because it is more aggressive than other types of breast cancer, it can spread more quickly and is more likely to recur.

How can I prevent TNBC? 

There is nothing you can do to prevent TNBC.

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What Are the Signs and Symptoms of TNBC?

Symptoms of TNBC are similar to other types of breast cancer and may include:

• A change in the size or shape of your breast.
• A dimpled, puckered, or "orange-peel" appearance of your skin.
• A lump or thickening on your breast or under your arm, which could be painless, firm, or fixed.
• A nipple that retracts (turns inward).
• Bloody or fluid discharge from your nipple.
• Breast or nipple pain.
• Red or swollen skin on your breast, nipple, or areola (the dark circle of skin around your nipple).
• Swollen lymph nodes under your arm or near your collarbone.

When should I see a doctor about my TNBC symptoms?

If you notice symptoms of TNBC, you should schedule an appointment with your doctor as soon as possible. Early diagnosis and treatment can improve your chances of survival.

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How Do You Diagnose TNBC?

To diagnose TNBC, your doctor will ask about your symptoms, perform a physical exam, and order imaging tests and a biopsy.

What to expect during your visit

If your doctor suspects TNBC, they will:

• Ask about your symptoms.
• Ask about family history of breast cancer.
• Perform a physical exam.
• Order a biopsy to learn about the type of cancer you have.
• Order imaging tests.
• Review your health history and medications.

Tests to diagnose TNBC

Imaging tests

Your doctor may order diagnostic imaging studies of your breast or other areas of your body, including:

• 3D mammogram (tomosynthesis) — A safe, noninvasive x-ray of your breast tissue. Your doctor may use computer-aided detection (CAD) software, which highlights abnormalities in your breast tissue.
• Chest x-ray — A painless, noninvasive test that creates an image of your chest and lungs.
• CT scan — A painless, noninvasive test that uses x-ray technology to capture multiple cross-sectional images of organs, bones, and tissues inside your body.
• Magnetic resonance imaging (MRI) — A safe, noninvasive imaging test that uses a magnetic field and radio waves to produce highly detailed images of breast tissue without radiation exposure.
• PET scan — Positron emission tomography (PET) is an imaging scan that shows abnormal cell activity within your body's tissues.
• Ultrasound (sonography) — A painless, noninvasive test that uses high-frequency sound waves to produce real-time pictures of your breast tissue.

Breast cancer biopsy and pathology testing

If your imaging tests show a suspicious area of breast tissue, your doctor will perform a biopsy. During a biopsy, your doctor will remove a sample of tumor tissue and send it to the lab for testing.

Types of breast biopsies include:

• MRI-guided breast biopsies — Use MRI guidance to precisely locate suspicious areas of breast tissue so they can be removed to check for signs of cancer.
• Stereotactic breast biopsies — Use mammography guidance to precisely locate suspicious areas of breast tissue so they can be removed to check for signs of cancer.
• Ultrasound-guided breast biopsies — Use ultrasound guidance to precisely locate suspicious areas of breast tissue so they can be removed to check for signs of cancer.

A doctor called a pathologist will perform tests to determine whether your cancer has HER2 proteins or hormone receptors. Your test results will give your doctor more information about the type of breast cancer you have, which will be used to guide your treatment.

TNBC prognosis

Compared to other types of breast cancer, TNBC grows and spreads more quickly and is more likely to recur. As a result, survival rates for people with TNBC are lower than they are for other types of breast cancer, even with treatment. 

How fast can TNBC recur?

TNBC is an aggressive cancer with a high risk of recurrence. Recurrence can happen anywhere from months to years after initial treatment is complete.

What is the survival rate for TNBC?

According to the American Cancer Society, the five-year relative survival rate for people with localized TNBC is 91%. That means that women with TNBC are 91% as likely as women without TNBC to live for at least five years after diagnosis.

The five-year relative survival rate for regional TNBC that has spread to the lymph nodes or other nearby structures is 66%, and the rate for metastatic TNBC is 12%.

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How Do You Treat TNBC?

The goals of TNBC treatment are to remove or destroy the cancer cells and reduce the risk of recurrence.

Treatment options may include:

Surgery for TNBC

Surgery may be an option for TNBC that has not spread beyond the breast or nearby lymph nodes.

Your doctor may recommend surgical procedures, including:

Breast cancer surgical procedures

• Lumpectomy — Also known as breast-conserving surgery or partial mastectomy, a lumpectomy is a surgical procedure to remove the part of your breast with a cancerous tumor and some healthy surrounding tissue.
• Mastectomy — A surgical procedure to remove the entire breast. When both breasts are removed, it is known as a double mastectomy.

Lymph node surgical procedures

• Axillary lymph node dissection — Surgery to remove all or a group of lymph nodes in the axilla (armpit), if your sentinel lymph node biopsy is positive for cancer.
• Sentinel lymph node biopsy — A minimally invasive procedure to remove the sentinel (main) lymph node in the axilla (armpit) to test it for cancer. It is performed to determine if cancer has spread to your lymph nodes.

Radiation therapy for TNBC

Radiation oncology is a medical specialty that uses radiation therapy to kill cancer cells. Radiation therapy for breast cancer involves using high-energy x-rays to precisely target your tumor. It may be used after surgery or in combination with other therapies to treat TNBC.

Medical oncology for TNBC

Medical oncology for breast cancer involves using different types of anti-cancer medications to slow or stop breast cancer growth. Your doctor may recommend treatments including:

Chemotherapy for TNBC

Chemotherapy is a breast cancer treatment that uses medications that travel through your bloodstream to kill cancer cells throughout your body. It may be used by itself or in combination with other treatments.

Your doctor may recommend chemotherapy:

• After surgery, to kill any remaining cancer cells.
• Before surgery, to shrink the tumor so it can be removed more easily.
• If your cancer has spread to other areas of your body.

Targeted therapy for TNBC

Your doctor may recommend targeted therapies, such as PARP inhibitors or antibody drug conjugates, to treat metastatic TNBC or TNBC linked to BRCA gene mutations. Targeted therapies work similarly to antibodies produced naturally by your immune system. These antibodies identify and attack foreign cells, including cancer cells.

Immunotherapy for TNBC

Immunotherapy is a breast cancer treatment that uses medications to boost your immune system’s ability to identify and kill cancer cells. It is often used in combination with chemotherapy to treat TNBC.

TNBC clinical trials

UPMC experts participate in national, multicenter clinical trials that study promising treatments for TNBC.

This means you can take part in research that has the potential to enhance breast cancer care and access groundbreaking treatments years before they are available to the public. Your doctor will let you know if a TNBC clinical trial might be an option for you. 

Why choose UPMC for TNBC care? 

When you choose UPMC for TNBC care, you will receive:

• Comprehensive breast cancer expertise — The breast cancer experts at UPMC provide state-of-the-art care for every form of breast cancer at every stage of the disease.
• Personalized, collaborative care — Our surgical, medical, and radiation oncologists work together to plan the best course of therapy for you.
• Supportive services tailored to your needs — Our approach to breast cancer care honors your preferences by blending advanced clinical methods with supportive services for the best possible results. 

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By UPMC Editorial Staff. Last reviewed on 2025-09-18.