Treatments for triple-negative breast cancer

Triple-negative breast cancer (TNBC) means that the cancer cells don't have any of the markers commonly found in breast cancer. TNBC does not have:

• hormone receptors for estrogen and progesterone
• too much of the HER2 protein (called overexpression of HER2)

Your doctor will test a sample of the breast cancer cells for these markers. Find out more about the hormone receptor status test and the HER2 status test.

Some cancer treatments, such as hormone therapy and trastuzumab (Herceptin and biosimilars), target these receptors and proteins to stop the cancer from growing. Because TNBC doesn’t have hormone receptors or overexpression of HER2, it has its own treatment options.

TNBC is usually invasive ductal carcinoma. It tends to be a high-grade tumour that grows and spreads quickly. TNBC is often diagnosed when the cancer has already spread to lymph nodes or other parts of the body.

The following are treatment options for TNBC. Your healthcare team will suggest treatments based on your needs and work with you to develop a treatment plan.

Breast-conserving surgery or a mastectomy is usually offered for TNBC. It may be the first treatment used, or it can be done after chemotherapy. The type of surgery and when it's done depends on the size of the tumour and where the cancer has spread.

A sentinel lymph node biopsy is usually done to check if the cancer has spread to nearby lymph nodes under the arm. An axillary lymph node dissection (ALND) may be done if the cancer has spread to nearby lymph nodes.

You may have breast reconstruction surgery after a mastectomy.

Find out more about surgery for breast cancer and breast reconstruction.

Chemotherapy uses drugs to destroy cancer cells. Chemotherapy is almost always offered for TNBC. It may be used before surgery to help shrink large tumours or treat tumours that have spread to nearby lymph nodes under the arm. It is also used after surgery to help lower the chance of the cancer coming back or to treat any cancer cells still in the body.

The following chemotherapy drugs are often used alone or in combination to treat TNBC:

• cisplatin
• carboplatin
• doxorubicin
• cyclophosphamide
• paclitaxel
• nab-paclitaxel
• gemcitabine
• capecitabine

Sacituzumab govitecan (Trodelvy) is an antibody drug conjugate, which is a targeted therapy drug combined with a chemotherapy drug. It is used to treat metastatic TNBC when surgery can't be done (the cancer is unresectable) and the cancer has already been treated with chemotherapy.

Find out more about chemotherapy for breast cancer and targeted therapy for breast cancer.

Radiation therapy uses high-energy rays or particles to destroy cancer cells. You may be offered radiation therapy for TNBC. It's always given to the breast after breast-conserving surgery. It may also be given to the chest wall and nearby lymph nodes under the arm.

Radiation therapy may also be given to areas of cancer that have spread beyond the breast and nearby lymph nodes.

Find out more about radiation therapy for breast cancer.

Immunotherapy helps to strengthen or restore the immune system's ability to fight cancer. You may be offered immunotherapy for TNBC.

Pembrolizumab (Keytruda) may be given with chemotherapy before surgery for TNBC that is at high risk of coming back. It may be continued after surgery. Pembrolizumab combined with chemotherapy may also be used to control the growth of metastatic TNBC that has too much PD-L1 protein.

Atezolizumab (Tecentriq, Tecentriq SQ) is combined with nab-paclitaxel to treat locally advanced or metastatic TNBC that has too much PD-L1 protein.

Immunotherapy drugs for TNBC may not be available in all areas or covered by all provincial and territorial health plans.

Find out more about immunotherapy for breast cancer.

Talk to your doctor about clinical trials open to people with breast cancer in Canada. Clinical trials look at new ways to prevent, find and treat cancer. Find out more about clinical trials.

You may want to consider a type of care to make you feel better without treating the cancer itself. This may be because the cancer treatments don't work anymore, they're not likely to improve your condition or they may cause side effects that are hard to cope with. There may also be other reasons why you can't have or don't want cancer treatment.

Talk to your healthcare team. They can help you choose care and treatment for advanced cancer.