Certain cancers, most commonly breast and prostate cancer, rely on hormones such as estrogen, progesterone, or testosterone to grow. Hormonal therapy works by blocking these hormones from reaching cancer cells, or by lowering hormone levels in the body altogether — slowing tumour growth, reducing recurrence risk, and in many cases offering years of effective, well-tolerated disease control.

Treatment begins with hormone receptor testing of the tumour to confirm it is hormone-sensitive and likely to respond. Based on the results, an appropriate approach is selected — this may include medications that block hormone receptors directly, drugs that lower hormone production in the body, or, in select cases, surgical or medical suppression of the ovaries or testicles. Treatment duration is often longer than chemotherapy, commonly continuing for several years, with regular monitoring to track effectiveness and manage any side effects such as bone density changes or menopausal symptoms.