Aromatase inhibitors are a class of drugs used in the treatment of hormone receptor-positive breast cancer. These drugs work by blocking the enzyme aromatase, which converts androgens into estrogen in the body. By inhibiting aromatase, these drugs effectively lower the levels of estrogen in the body, which can help slow or stop the growth of hormone receptor-positive breast cancer cells. Aromatase inhibitors are commonly used as part of hormonal therapy in postmenopausal women with breast cancer, either alone or in combination with other treatments such as surgery, radiation, or chemotherapy.