Molecular endocrinology and breast cancer--a reed before the wind lives on (a tribute to Professor Mike Reed).

Oestrogens in breast cancers are derived from both uptake from the circulation and in situ synthesis. Third generation aromatase inhibitors (AIs) effectively block aromatase activity within the breast. The effects of AIs on the molecular biology of breast cancers may be monitored in patients given neoadjuvant therapy. Changes in tumour gene expression associated with AIs is influenced by time of drug exposure and gene expression profiles may provide important information on tumour response/ resistance to AIs.