What is triple negative breast cancer?

There are many different kinds of breast cancer, and the type that you have will impact the cancer treatment you receive. Triple negative breast cancer accounts for 15% of all breast cancer cases and is an invasive breast cancer, which means the cancer has grown out of the area where it developed and has begun to rapidly spread to nearby breast tissue.²

It is classified as triple negative because it does not have the three proteins that are typically found on breast cancer cells: oestrogen, progesterone and HER2 receptors.³ For women younger than 40-years-old or who have the BRCA1 or BRCA2 gene mutation, there is an increased risk of developing triple negative breast cancer.¹

As chemotherapy is generally very effective at treating early stage triple negative breast cancer, you may be treated with chemotherapy before surgery to reduce the size of the tumour, or after to decrease the risk of cancer recurrence.²

There are also a number of emerging treatments such as immunotherapy that may continue to help triple negative breast cancer patients. Results from a Phase III trial, KEYNOTE-522 showed pembrolizumab (Keytruda) in addition with chemotherapy results in better response rates for early triple negative breast cancer. Please talk to your doctor about whether clinical trials may be an option for your cancer.

Both men and women have BRCA1 and BRCA2 genes, which help to prevent the development of cancer. In cases where there is a mutation in these genes, people have a higher risk of developing a number of cancers. BRCA1 and BRCA2 mutations are known to increase the risk of triple negative breast cancers. Following diagnosis of triple negative breast cancer in young women, genetic counselling and testing may be considered to identify whether the BRCA1 or BRCA2 mutation has impacted the cancer’s development.