Aromatase inhibitors are established as first line palliative therapy in metastatic breast cancer but as yet are only considered appropriate adjuvant hormonal therapy for early breast cancer in certain patients.
For 30 years, tamoxifen has been the initial hormonal treatment of choice for women with early or advanced hormone-sensitive breast cancer. Over the last five years, the specific aromatase inhibitors have challenged that role in postmenopausal women.
What are specific aromatase inhibitors?
In postmenopausal women, the major source of circulating oestrogens is the conversion of precursors (mainly androstanedione) by an aromatase in fat, liver and muscle tissues. Inhibiting this enzyme will reduce circulating oestrogen levels by about 95% and cause reduced activity of hormone-sensitive breast cancers.