Hormonal therapy for cancer

Hormone therapy is an effective and non-toxic therapy for oestrogen and progesterone receptor-positive breast cancer and prostate cancer. Serum levels of oestradiol and testosterone are controlled by the hypothalamic–pituitary–gonadal pathway. Oestradiol is produced in premenopausal women from the ovaries and in postmenopausal women by peripheral conversion of adrenal androgens by aromatase. In premenopausal women with breast cancer and men with prostate cancer, treatment is primarily achieved by castration. In postmenopausal women selective oestrogen receptor modulators (e.g. tamoxifen) or aromatase inhibitors are used. Hormone therapy can be used to reduce the size of the primary cancer prior to radical surgery or radiotherapy or to reduce the risk of recurrence. Hormone therapy is highly effective in patients with locally advanced or metastatic disease, with a high response rate. Most patients eventually relapse with ‘castrate-refractory’ disease, for which increasing numbers of active agents are entering clinical practice.