This work provides a concise and up-to-date account of endocrine therapy for breast cancer. It covers historical development, basic physiology of female sex hormones, role of hormones in breast cancer aetiology, selective oestrogen receptor modules, ovarian ablation and chemoprevention. The book aims to provide a concise and up-to-date medical guide to medical and surgical oncologist working in the field of breast cancer and reflects recent advances in molecular biology of the oestrogen receptor including descriptions of ongoing trials involving hormonal manipulation.