What makes someone a good candidate for letrozole treatment?

BreastCa+menopause. Is is usually used in patients with early breast cancer who have undergone menopause and have received other treatments such as surgery, radiation, or tamoxifen. It works by decreasing the production of estrogen in the body. See: http://www.Nlm.Nih.Gov/medlineplus/druginfo/meds/a698004.Html.
Post-menopausal. Letrozole is an aromatase inhibitor that is very effective in the treatment of hormone-sensitive (estrogen receptor positive) breast cancer, provided that the patient is post-menopausal. Depending on one's cancer stage, this may be used alone or in combination with traditional (IV) chemotherapy.