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. For women younger than 40-years-old or who have the BRCA1 gene mutation, there is an increased risk of developing a certain type of cancer known as triple negative breast cancer.¹

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

Triple negative breast cancer can be more aggressive and has limited treatment options compared to other types of breast cancer, which is why it is so important to find the cancer at an early stage. As the signs and symptoms of breast cancer are similar across all breast cancer types, regular self-examination should be conducted to assist you in identifying any changes in your body. For more information on breast cancer signs and symptoms, click here.

As triple negative breast cancer doesn’t have the hormone receptors oestrogen and progesterone or the HER2 protein, this means that hormone treatments and targeted therapies will not effectively treat the cancer.

Treatment for triple negative breast cancer may include surgery (involving the removal of the lump or the entire breast, known as a mastectomy), chemotherapy and/or radiation therapy.

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. The substantial improvement of 14% in response rate is clinically meaningful for patients.⁴ Please talk to your oncologist about suitable clinical trials 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. A BRCA1 mutation is 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 mutation has impacted the cancer’s development. To learn more about hereditary cancer, we encourage you to read Icon’s article on everything you need to know about BRCA1 and BRCA2.

Triple negative breast cancer is less common than other breast cancers, which means that it can be harder for women to get the support they need. Icon’s Young Women’s Cancer Program is here to support young women with triple negative breast cancer to navigate their treatment, find the right support, and access genetic counselling and testing.