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Triple-negative Breast Cancer

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If you or someone you know has been diagnosed with triple-negative breast cancer, you may be trying to learn as much as possible about the disease and its treatments. Read on to find out more.

The information on this website should be discussed with your healthcare professional and does not replace their advice.

What is triple-negative breast cancer?

Breast cancer is the most common cancer in women and can occur in men too. About 15% of breast cancers are diagnosed as triple negative.

Triple-negative breast cancer is a form of breast cancer that does not have receptors for oestrogen, progesterone or HER2.

Oestrogen and progesterone are hormones. HER2 is a protein involved in normal cell growth. Its full name is human epidermal growth factor receptor 2.

All breast cancers are tested for oestrogen, progesterone and HER2 receptors.

Treatment with KEYTRUDA® (pembrolizumab)

Your doctor will plan your treatment according to your individual circumstances. These include your type and stage of cancer, grade of cancer, age and general health.

KEYTRUDA is an immunotherapy that may be used to treat triple-negative breast cancer in combination with chemotherapy if:

  • Your breast cancer tests positive for a type of protein known as PD-L1, and it has returned and cannot be removed by surgery, or has spread (metastatic).
  • You have early-stage breast cancer and are at high risk of your breast cancer coming back. In this case, KEYTRUDA may be given in combination with chemotherapy before surgery and then continued alone after surgery.

Talk to your doctor to see if KEYTRUDA may be right for you.

KEYTRUDA is not funded in New Zealand for the treatment of patients with triple-negative breast cancer.


Expand for more information on terms and definitions related to triple-negative breast cancer.

Terms you may find useful:

Human epidermal growth factor receptor 2. This is a protein that occurs on all human cells.

Messenger chemicals in our bodies that control growth and reproduction.

A sex hormone that supports human reproduction.

A doctor who specialises in treating cancer with drug therapies – for example, chemotherapy and immunotherapy.

A protein that may protect cancer cells from being detected by the immune system.

The expected outcome of your cancer. Your doctor is the best person to ask about your prognosis, but it is not possible for anyone to predict the exact course of cancer.

A sex hormone that helps prepare a woman’s womb for pregnancy.

Are like tiny sensors in your body that detect and respond to signals or messages from other parts of your body.

A new or abnormal growth of tissue on or in the body. Tumours can be benign (not cancerous) or malignant (cancerous).

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Questions to ask your doctor

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Patient Resources


Cancer Council Australia. 2022. Understanding Breast Cancer. A guide for people with cancer, their families and friends.
Available at:
Accessed on 27/09/2022

Ministry of Health. 2021. New cancer registrations 2019.
Available at:
Accessed on 24/01/2022

Breast Cancer Foundation New Zealand. 2022. Receptor Status.
Available at:
Accessed on 30/06/2022

National Cancer Institute. NCI Dictionary of Cancer Terms. HER2.
Available at:
Accessed on 29/03/2021


KEYTRUDA Consumer Medicine Information

National Cancer Institute. NCI Dictionary of Cancer Terms. PD-L1.
Available at:
Accessed on 25/8/2020

National Cancer Institute. NCI Dictionary of Cancer Terms. Receptor.
Available at:
Accessed on 30/01/2024

NZ-KEY-00872. TAPS DA 2339KN TAPS NP20132. First Issued February 2024.