Aromatase Inhibitors

Aromatase inhibitors (AIs) are a group of drugs used to treat breast cancer. They work by blocking the enzyme aromatase, which converts hormones such as testosterone into the female hormone estrogen. By inhibiting the production of estrogen, AIs slow or stop the growth of hormone receptor positive (HR+), or hormone dependent, breast cancers. AIs are used after surgery, chemotherapy, or hormone therapy to reduce the risk of breast cancer recurrence or improve the chances of survival. They have also been found to reduce the risk of developing a new type of breast cancer in high-risk women. AIs are generally well-tolerated and may cause fewer side effects than other hormone therapies.