Metastatic Breast Cancer Treatment Review

If the cancer has metastasized to other areas of the body, treatment options may be more limited than what was available for the original cancer. However, there may be new drugs that are effective at slowing the growth and progression of the disease as opposed to curing it. For example, bisphosphonates are a class of drugs that are typically used to treat osteoporosis, but they have also shown promising results in slowing the progression of bone metastases.1

Treatment Options

Historically, metastatic breast cancer was considered to be untreatable, but recent developments have given light to how cancer grows and the many factors that are involved. The following are potential treatment options that may be available for metastatic breast cancer.

Chemotherapy – Chemotherapy drugs may be administered alone or in combination with other drugs.  Anthracycline and taxane-based therapies have typically shown the most promise for treating metastatic breast cancer. Several clinical trials have shown increased response rates but none seem to increase survival for an extended period of time. The common factor in these clinical trials seems to be taxane and more recent trials are even adding an antimetabolite, such as methotrexate. Targeted biologic agents are also being developed, called monoclonal antibodies. These are drugs that target cancer cells specifically and even enhance the activity of chemotherapy drugs that they can be given in combination with. Research is ongoing and new chemotherapy drugs are being developed all the time.

Endocrine Therapy – The hormone receptor status of your cancer may help determine hormonal therapy is an option for you.

In premenopausal women, estrogen is produced in the ovaries. If your cancer is strongly estrogen receptor positive, it is likely that your doctor will recommend a drug called tamoxifen or toremifene, which blocks the effects of estrogen in the breast. Newer studies are investigating another class of antiestrogens, called aromatase inhibitors. This class of drugs prevents conversion of androgens to estrogen.4

Postmenopausal women have ovarian failure, where the ovaries stop producing estrogen. This estrogen deprivation may help control the growth rate of cancer but only if the cancer is estrogen receptor positive. Other options for postmenopausal women include aromatase inhibitors, progestins and antiestrogens.

HER2 Treatments – Trastuzumab is a monoclonal antibody that specifically targets cells expressing the growth factor protein HER2. It is administered IV and may be given during or chemotherapy treatments. Another drug, Lapatinib, is also being used for those who have already been treated with anthracycline, taxane and trastuzumab. It is taken by mouth and tends to have less cardiac toxicity, but does have a higher risk of causing liver damage.

References

1 American Cancer Society. (2004). A Breast Cancer Journey: Your Personal Guidebook. Atlanta: American Cancer Society.

2 Robert, N. J., Dieras, V., Glaspy, J., et al. (2011). RIBBON-1: Randomized, Double-Blind, Placebo-Controlled, Phase III Trial of Chemotherapy With or Without Bevacizumab for First-Line Treatment of Human Epidermal Growth Factor Receptor 2–Negative, Locally Recurrent or Metastatic Breast Cancer . Journal of Clinical Oncology, 1252-1260.

3 Miller, K., Wang, M., Gralow, J., et al. (2007). Paclitaxel plus Bevacizumab versus Paclitaxel Alone for Metastatic Breast Cancer. The New England Journal of Medicine, 2666-2676.

4 Paridaens, R. J., Dirix, L. Y., Beex, L. V., et al. (2008). Phase III Study Comparing Exemestane With Tamoxifen As First-Line Hormonal Treatment of Metastatic Breast Cancer in Postmenopausal Women: The European Organisation for Research and Treatment of Cancer Breast Cancer Cooperative Group . Journal of Clinical Oncology, 4883-4890.

This article was originally published on July 27,2012 and last revision and update of it was 9/2/2015.