AI is code for oral anti hormone treatment for hormone positive breast cancer in post menopausal women. It stands for Aromatase Inhibitor and it inhibits the Aromatase needed to produce estrogen. There are three AI’s Anastrozole, Letrazole and Exemestane. they are taken daily for 5-10 years after surgery to limit the amount of estrogen available to breast cancer cells that “ feed” on estrogen.

Only hormone based breast cancers qualify for an Oncotype evaluation.