Endocrine therapy

Authors: Sarah Gierahn Nielsen, med. student & Hanne Melgaard Nielsen, MD

Endocrine therapy (adjuvant hormonal therapy) in general reduces the risk of breast cancer recurrence at all sites; both loco-regional and distant. The choice of treatment depends on the menopausal status.
Patients with estrogen receptor positive breast caner are offered endocrine therapy unless the patients are categorized as low risk:

• Age more than 60
• Tumor < 10 mm or less
• No lymph node involvement
• Low grade cancer

Tamoxifen was discovered in the 1960’s and is the first oncologic targeted treatment. It is a type of selective estrogen receptor modulator (SERM), that blocks the estrogen receptor and thereby prevents the effects of estrogen in breast tissue. It is offered to premenopausal women for a period of 10 years.

Aromatase inhibitors, as the name implies, inhibits the aromatase enzymes thus preventing the formation of estrogen. It is given to postmenopausal women who have had hormone-dependent breast cancer for 5 years