Since triple-negative breast cancer lacks receptors for the hormones estrogen, progesterone, and the human epidermal growth factor (HER2) protein that are present in other breast cancers, this cancer cannot be treated with hormone therapies and HER2 protein receptors administered for other breast cancers. Therefore, other therapies such as lumpectomy (breast conserving surgery), mastectomy, breast reconstruction, radiation therapy, chemotherapy, and immunotherapy are used to treat triple-negative breast cancer.
Treatment decisions are based on the stages of the triple-negative breast cancer:
Stages I-III triple-negative breast cancers are usually treated with lumpectomy (breast conserving surgery) or mastectomy, followed by radiation if the cancer has spread to nearby lymph nodes. Chemotherapy may be administered before surgery (neoadjuvant) to reduce the size of a large tumor before resection. For residual cancer after neoadjuvant chemotherapy, the oral chemotherapy drug, capecitabine, may be prescribed for 18-24 weeks. Chemotherapy may also be administered after surgery (adjuvant) to lower the chances of the cancer reoccurring.
Stage IV triple-negative breast cancer is usually treated first with chemotherapy, as the cancer has spread to other areas of the body. Chemotherapy medications for Stage IV include anthracyclines, capecitabine, eribulin, gemcitabine, and others.
Women with triple-negative breast cancer who carry the BRCA gene mutation, and for who chemotherapy medications are no longer working, other medications, such as carboplatin or cisplatin (platinum medications) or targeted PARP inhibitors, Olaparib (Lynparza) and talazoparib (Talzenna), may be administered.
A form of advanced triple-negative breast cancer that produces a PD-L1 protein (20% of triple-negative breast cancers) may initially be treated with the immunotherapy medication of atezolizumab combined with Abraxane (nab-paclitaxel).
Lumpectomy (Breast-Conserving Surgery) is a surgical procedure where the breast lump is removed, along with a few lymph nodes to determine whether the cancer has spread. This surgery is usually done for early stage breast cancer for a small breast lump, on an outpatient basis, and may be followed with radiation therapy.
Mastectomy is a surgical procedure where the affected breast is removed, along with nearby lymph nodes to determine whether the cancer has spread. Patients may elect to have a Breast Reconstruction procedure performed directly following mastectomy during the same surgical session.
Radiation therapy usually follows lumpectomy (breast-conserving surgery) where high levels of radiation are directed at the affected breast to kill any residual cancer. Radiation therapy for breast cancer is usually administered four-to-five days a week for six weeks.
Chemotherapy is the primary systemic treatment option for triple-negative breast cancer and is administered to kill any cancers cells that may have spread elsewhere in the body, as well as to lower the chances of the cancer reoccurring. While triple-negative breast cancer usually demonstrates a good response to initial chemotherapy, the cancer tends to reoccur.
Immunotherapy is a newer approach to cancer treatment that helps the patient’s own immune system to kill cancer cells, often by targeting certain proteins (immune checkpoint inhibitors) that help cancers avoid the immune system response, such the PD-L1 protein. Tecentriq (atezolizumab), an immune checkpoint inhibitor administered in combination with the chemotherapy, Abraxane (nab-paclitaxel), is the first immunotherapy treatment approved for locally advanced or metastatic (spreading) triple-negative, PD-L1-positive breast cancer.
Patients with triple-negative breast cancer may also consider participating in clinical trials for new treatments because these may allow for access to medications not otherwise available for treatment.
Patients undergoing treatment for triple-negative breast cancer may experience treatment-related side effects, which depend on the treatment, and more commonly include swelling in the arm (lymphedema), nausea and vomiting, skin and nail changes, and loss of hair. Treatment for these and other side effects is an essential part of breast cancer care.