What is stage 4 breast cancer?
Stage 4 breast cancer is also known as metastatic breast cancer. When the cancer has spread into distant organs and sites such as the bones, liver, lungs, or brain (technically speaking undergone metastasis), it is referred to as stage 4 breast cancer. It is considered difficult to treat, but the evolution of new treatments has opened up the possibility of longer survival rates and better treatment outcomes for patients in advanced stages.
Features indicative of stage 4 breast cancer as per TNM staging:
- The tumour can be of any size, and usually large (Any T)
- Lymph nodes have usually been affected with cancer cells (Any N)
- The cancer has already spread (metastasis) to other parts of the body, such as the bones, lungs, liver or brain.(M1 disease)
Treatment for stage 4 breast cancer
The main goal in metastatic breast cancer is to prolongation of survival, alleviating patient symptoms and improvement in quality of life. The intent would be palliative rather than curative. The treatment options in this stage depends on Hormonal receptor status, HER2 status and patient disease status.
Women whose breast cancers have been diagnosed to be hormone receptor-positive, which means over expression of hormonal receptors ER and PR, may be administered hormone therapies, such as Tamoxifen or an aromatase inhibitor in order to slow down or stop the growth of tumors. In patients with visceral metastasis and rapidly progressive disease, chemotherapy is generally preferred.
Drugs that target some specific characteristics of cancer cells (targeted therapies) may be used to block the effects of enzymes or proteins that would otherwise promote the growth of cancer cells. Targeted agents that have proven efficacy in metastatic breast cancer are mainly Trastuzumab, Pertuzumab, Lapatinib, CDK 4/6 inhibitors. Surgery and/or radiation are rarely used, especially in palliation of symptoms like bone and brain metastasis. Surgical or radiation treatments are usually given to stage 4 breast cancer patients to provide symptomatic relief.