Anastrozole is a medication primarily used in the treatment of hormone receptor-positive breast cancer in postmenopausal women. It belongs to a class of drugs known as aromatase inhibitors, which work by reducing the production of estrogen in the body. Estrogen can promote the growth of certain types of breast cancer cells. By lowering estrogen levels, anastrozole helps slow down or stop the growth of cancer cells, ultimately improving outcomes in breast cancer treatment. Anastrozole is typically taken orally in tablet form.