A pure antiestrogen may avoid tamoxifen’s adverse effects

Abstract

Tamoxifen is widely used as an antiestrogen therapy for all stages of estrogen receptor-positive breast cancer, particularly for advanced disease. However, as well as having an antagonist effect at the estrogen receptor, tamoxifen also has a partial agonist effect in some tissues. While this agonist effect may be positive in terms of a patient’s bone mineral density and blood lipid profiles, it has also been associated with endometrial cancer and with stimulation of the breast cancer tumour itself. ICI-182780 [‘Faslodex’; Zeneca] is a ‘pure’ antiestrogen agent that exerts its effect without an accompanying stimulation of tumours or other tissue. Preliminary data suggested that ICI-182780 may avoid some of the drawbacks of tamoxifen and find a role as primary, or at least secondary, endocrine treatment for patients with breast cancer. ^* The latest clinical developments with ICI-182780 were outlined at a Zeneca-sponsored symposium at the 9th European Cancer Conference (ECCO) [ Hamburg, Germany; September 1997 ].