How does Letrozole Work?

Hormone therapy for breast cancer is a treatment for breast cancers that are sensitive to hormones. The most common forms of hormone therapy for breast cancer work by blocking hormones from attaching to receptors on cancer cells or by decreasing the body’s production of hormones.⁠

Hormone therapy is only used for breast cancers that are found to have receptors for the naturally occurring hormones estrogen or progesterone.⁠

Hormone therapy for breast cancer is often used after surgery to reduce the risk that the cancer will return. Hormone therapy for breast cancer may also be used to shrink a tumor before surgery, making it more likely the cancer will be removed completely.⁠

Aromatase inhibitors are a class of medicines that reduce the amount of estrogen in your body, depriving breast cancer cells of the hormones they need to grow.⁠

Aromatase inhibitors are only used in women who have undergone menopause. They cannot be used unless your body is in natural menopause or in menopause induced by medications or removal of the ovaries.⁠

Letrozole is used to reduce the risk of cancer recurrence in women who have been treated for early-stage breast cancer. It can be used alone or given after completing tamoxifen treatment. Letrozole is also used to treat advanced breast cancer.

Mayo Clinic