**3.4 Hormone therapy**

Hormone therapy, also called "endocrine-based therapy", is a systemic treatment and plays an important role in breast cancer therapy. It is the first type of systemic treatment directed at a specific target, the hormone-dependent cancer cell, and may be referred to "targeted therapy" (Hind et al., 2007). The purpose of hormone therapy is to add, block or remove hormones. There are certain hormones that can attach to breast cancer cells and affect their ability to multiply such as tamoxifen, fareston, arimidex and so on (Jones& Buzdar, 2004). Hormone therapy may be used alone or in combination with radiation therapy. It is rarely used simultaneously, but is often used following chemotherapy. The benefits and side effects of the drugs relate only to the natural effects of the hormone itself and the hormonecancer cell interaction. For that reason, the typical side effects seen with chemotherapy are not present with hormone or endocrine-based therapies (Hind et al., 2007).
