Treatment for metastatic breast cancer
Metastatic breast cancer occurs when the cancer has already spread beyond the breast tissue or lymph nodes, and extended into other parts of the body, such as the bones, liver, lungs or brain. Primarily, the intent of treatment in these patients is palliative. Generally, stage 4 breast cancer patients require systemic therapy. This includes hormone therapy, chemotherapy, targeted therapies, or a combination of these three treatment types. Moreover, doctors advise surgery and radiation are generally to either treat symptoms or prevent symptomatic pain in stage 4 patients.
Treatment options for metastatic breast cancer
There are three main modalities of treatment for metastatic breast cancer:
- Hormonal therapy
- Chemotherapy
- HER-2 targeted therapy
Systemic treatment for stage 4 (metastatic) breast cancer
The different types of medicines for stage 4 breast cancer, depend on the cancer subtype, the hormone receptor status of the patient, as well as their HER2 status.
Hormone receptor-positive cancers: Firstly, patients with hormone receptor-positive (ER+ or PR+) cancers need hormone therapy (using tamoxifen or an aromatase inhibitor). Premenopausal women are often given tamoxifen first, whereas the drug of choice in postmenopausal women is Aromatase inhibitors. Chemotherapy is often the first line of treatment to treat the basic symptoms for such patients, when the disease is rapidly progressing. This is because, hormone therapy takes a very long time to respond (sometimes up to a few months).
Hormone receptor-negative cancers: Chemotherapy is the most effective treatment for patients with hormone receptor-negative (ER- or PR-) cancers. This is because hormone therapy cannot help in relieving their symptoms.
HER2-positive cancers: The targeted drug Trastuzumab can help women whose cancer indicates HER2-positive. Such patients can live for a longer time if Trastuzumab goes hand in hand with chemotherapy, hormonal therapy or other anti-HER2 drugs such as Pertuzumab, ado-Trastuzumab emtansine, and Lapatinib.
HER2-negative, BRCA gene mutation positive: Patients with HER2 negative and who have BRCA germline mutation can be treated with PARP inhibitors like Olaparib.
Use of surgery or radiation in the treatment of metastatic breast cancer
Surgery and/or radiation are used mostly for symptom management in the case of metastatic (stage 4) breast cancer patients. Such possibilities include:
- Spread to the brain (Brain metastasis)
- Spread to bone (Bone metastasis)
- Spinal cord suppression
- Liver metastasis
- For other symptomatic pain relief