Hormones that are naturally produced in the body can cause some cancers to grow. The aim of hormone therapy (also called endocrine therapy or androgen deprivation therapy) is to lower the amount of hormones the tumour receives. This can help reduce the size and slow down the spread of the cancer. Hormone therapy can be used for a short time or long term.
Oestrogen helps some types of breast cancer to grow. Anti-oestrogen drugs (such as tamoxifen, goserelin and aromatase inhibitors) are used in hormone therapy to treat oestrogen-sensitive cancers. They can help slow or stop new breast cancers developing.
Side effects of hormone therapy
Some people have no side effects from these drugs, while others experience symptoms similar to menopause, including vaginal dryness or discharge, pain during intercourse, hot flushes, weight gain, decrease in sex drive and arousal, night sweats, urinary problems and mood swings. You should have regular gynaecological check-ups after hormone therapy as there is a small risk of developing cancer in the lining of the uterus (endometrial cancer).
Androgen deprivation therapy (ADT) is a type of hormone therapy that slows the production of testosterone. If you have ADT to treat prostate cancer, you may feel tired, or have erection problems, reduced sex drive, weight gain, hot flushes, breast growth and tenderness, depression, and loss of bone density (osteoporosis).