Anastrozole Uses to treat early-stage hormone receptor-positive breast cancer. It is also utilized as the first-line treatment for hormone receptor-positive or hormone receptor-unknown advanced or metastatic (spread) breast cancer. Anastrozole is a medication used to treat breast cancer, particularly in women who have completed menopause. When breast cancer cells proliferate, they may be fuelled by hormones such as estrogen. Anastrozole works by reducing estrogen levels in the body, which can prevent or stop the growth of cancer cells. It is frequently administered to women who have hormone receptor-positive breast cancer, which implies their cancer cells respond to estrogen.