Targeted therapy is a type of breast cancer treatment which involves targeting cellular processes to stop the growth of cancer cells. The drugs used in this therapy usually target proteins or molecules of the cells involved in the growth and survival of the cancer cells. Targeted therapies are more specific to cancer cells, unlike traditional chemotherapy, which is generalized to any rapidly dividing cells, such as hair follicle cells and the cells lining the mouth or the intestine, leading to side-effects.
This therapy primarily involves identifying appropriate targets that play an important role in the growth of cancer cells. Identification is usually done by comparing cancer cells with normal cells to identify proteins characteristic to cancer cells, and those involved in their growth and division. Once these proteins are identified, a therapy (drug) is developed to act on these proteins and cease their ability to bind to their receptors, hence decreasing their activity.
Some of the targeted therapies include:
- Hormone therapies slow down or prevent the growth of tumors that are fueled by hormones.
- Signal transduction inhibitors stop the transfer of signals that a cell receives to illicit a response.
- Gene expression modulators change the function of proteins that control the expression of certain genes.
- Apoptosis inducers promote apoptosis or controlled cell death of cancer cells.
- Angiogenesis inhibitors initiate tumor angiogenesis, a process by which the development of new blood vessels to the tumors are blocked.
- Immunotherapies initiate the body’s defense system to destroy the cancer cells.
- Monoclonal antibodies specifically identify and destroy cancer cells.
However, targeted therapy has a few limitations such as resistance of the cancer cells to the drug, or difficulty in production of some drugs for the identified cancer cell targets. Like most therapeutic procedures, targeted therapy may have a few complications such as high blood pressure, skin problems such as rashes or dry skin, delayed blood clotting or wound healing or gastrointestinal perforation.