Triple negative breast cancer
What is triple negative breast cancer?
Triple negative breast cancer is a type of breast cancer that does not have any of the three receptors commonly found on breast cancer cells – the oestrogen, progesterone and HER2 receptors. Around 15% of breast cancers are triple negative.
Triple negative breast cancer generally responds well to chemotherapy. Five years after diagnosis, people with triple negative breast cancer are no more likely to experience a recurrence of their breast cancer than people with other types of breast cancer1. In the longer term (over 10 years), a recurrence is less likely with triple negative breast cancer2.
Treatment for triple negative breast cancer
Treatment for triple negative breast cancer usually involves surgery (breast conserving or mastectomy), radiotherapy if breast conserving surgery was performed, and chemotherapy. If you would like to read more about the main types of breast cancer surgery, visit the surgery section of this website.
As triple negative breast cancer is usually very responsive to chemotherapy, your medical oncologist will most likely develop a chemotherapy treatment plan for you. This will take into account your own individual needs and preferences.
Chemotherapy is usually given after breast cancer surgery. Sometimes it is given before surgery to shrink the tumour to allow for a smaller and easier operation. Some people may be offered chemotherapy before surgery; this is called neoadjuvant chemotherapy.
How is triple negative breast cancer different from other types of breast cancer?
Triple negative breast cancer is different from other types of breast cancer because it does not have any of the three receptors commonly found on breast cancer cells:
- Oestrogen (ER)
- Progesterone (PR)
- Human Epidermal Growth Factor Receptor 2 (HER2)
If you have triple negative breast cancer, you may notice that your treatment is slightly different from that offered to other people with breast cancer.
People with oestrogen and/or progesterone receptor positive breast cancer will usually take tamoxifen or an aromatase inhibitor as part of their treatment. People with HER2 positive breast cancer will usually take a drug called Herceptin. These drugs are not effective against triple negative breast cancer.
Known risk factors
Anyone can get triple negative breast cancer, however the known risk factors are:
Everyone has BRCA1 and BRCA2 genes. These genes normally prevent the development of cancers. However, around 5-10% of people with breast cancer have a mutation of their BRCA1 or BRCA2 genes. People with a mutation in one of these genes have a higher risk of developing breast, ovarian and other cancers through their lives.
A BRCA1 mutation is associated with a higher risk for triple negative breast cancer. However, not all breast cancers caused by BRCA mutations are triple negative. BRCA2 mutations are more likely to be present in oestrogen receptor positive (ER+) breast cancer.
If you have a very strong family history of breast cancer, it is possible that you and your relatives could carry a BRCA mutation. For more information on breast cancer and family history, visit the Breast cancer in the family section of this website.
Premenopausal women have a higher rate of triple negative breast cancer than postmenopausal women. Scientists do not yet understand why this is the case, however research is currently underway in this area.
There are many different types of breast cancer and each one is treated differently. As triple negative breast cancer is a less common form of breast cancer, some people find it difficult to explain their treatment options to others.
Some people find the support of others who have triple negative breast cancer helpful, as they share similar experiences. If you would like to connect with other people with this type of breast cancer, our online network has a dedicated support group for those living with a diagnosis of triple negative breast cancer. You are most welcome to join.
Research into triple negative breast cancer
Researchers are working to find new treatments for triple negative breast cancer. Much of this research involves looking for molecules in the body that are involved with cancer growth, and formulating a drug that will ‘disable’ how that molecule works.
Clinical trials are in progress to determine whether these new drugs are better than the current standard treatment. If you would like more information on clinical trials, visit the clinical trials section of our website.
1. TNBC: classification and management N McCarthy et al Asia-Pac J Clin Oncol 2012; 8: 145-155.