Hormone therapy, also known as endocrine therapy, is a treatment option commonly used in the management of hormone-sensitive cancers such as breast cancer and prostate cancer. It works by altering hormone levels in the body or blocking hormone receptors to slow down or prevent the growth of cancer cells. In breast cancer, hormone therapy targets estrogen receptors (ER-positive) or progesterone receptors (PR-positive) on cancer cells. It may involve medications that either reduce estrogen levels in the body or block the effects of estrogen on cancer cells. Hormone therapy is often used as adjuvant therapy after surgery to reduce the risk of cancer recurrence or as palliative treatment for advanced or metastatic breast cancer. Hormone therapy is generally well-tolerated but may cause side effects such as hot flashes, fatigue, loss of libido, and osteoporosis. The specific type of hormone therapy, duration of treatment, and potential side effects vary depending on the type and stage of cancer being treated.