There are different ways of reducing the level of female hormones in the body:
- anti-oestrogens, eg tamoxifen
- aromatase inhibitors, eg anastrozole (Arimidex®), letrozole (Femara®), exemestane (Aromasin®)
- anti-ovarian treatments, eg surgery, radiotherapy, goserelin (Zoladex®).
Anti-oestrogens
Anti-oestrogens work by stopping breast cancer cells from getting oestrogen. The most common anti-oestrogen is tamoxifen. Tamoxifen can be used to treat women of any age, regardless of whether they have reached menopause. Tamoxifen is taken as a single daily tablet, usually for 5 years.
Aromatase inhibitors
Aromatase inhibitors work by blocking the conversion of androgens to oestrogen. They are only effective for women who have gone through menopause permanently. If you have not yet reached menopause, or if you are in the middle of menopause, your ovaries are still producing oestrogen, so aromatase inhibitors will not be effective for you. If you have become menopausal temporarily because of chemotherapy, aromatase inhibitors are not suitable for you because your ovaries may start producing oestrogen again. Aromatase inhibitors are taken as a single daily tablet, usually for 5 years.
Anti-ovarian treatments
Anti-ovarian treatments work by stopping the ovaries from producing oestrogen. Drugs like goserelin stop the ovaries from producing oestrogen temporarily for the duration of taking the drug. A permanent method of stopping oestrogen production in women is to remove the ovaries or administer radiotherapy to the ovaries. Anti-ovarian treatments are only suitable for women who have not yet reached menopause.
