As mentioned, Fareston belongs to a group of medications called selective estrogen receptor modulators. SERMs work by binding to estrogen receptors in the body.
Estrogen receptors are slightly different in various areas of the body, and the effects of SERMs can therefore vary by body tissue. In some body tissues, SERMs bind to estrogen receptors and have estrogenic effects (they act like estrogen). In other body tissues, SERMs bind to estrogen receptors and have anti-estrogenic effects (they block the effects of estrogen).
Many breast cancers are estrogen sensitive, which means the tumor grows in response to estrogen. Breast cancer tumors that are sensitive to estrogen are known as estrogen receptor-positive tumors (or sometimes hormone receptor-positive tumors). They have estrogen receptors on their surface. When estrogen fits into these receptors, the tumor grows.
Fareston works to treat breast cancer because it has anti-estrogenic effects on breast tissue. When the drug binds to the estrogen receptors on estrogen receptor-positive tumors, it prevents estrogen from also binding. As a result, estrogen cannot make the tumor grow and cancer progression is slowed down.
Fareston has not been studied in children, and is not approved for use in this age group. Because it is used to treat certain types of breast cancer in postmenopausal women, Fareston use in children is not likely. You can talk to your child's healthcare provider about the particular risks and benefits of giving this medicine to children.
Fareston can be used in older adults. The average age of women in clinical studies ranged from age 60 to 66. In these studies, there were no differences in side effects or the effectiveness of the medication in younger and older individuals.