- Prior treatment with letrozole or tamoxifen uncontrol disorders patients with instable angina or uncontrol cardiac disease patient with bilateral breast tumors patients elegies for conservative breast surgery Inflammatory breast cancer o distant metastases Other concurrent malignancies, except carcinoma with in situ cono biopsy of uterine cervix or adequate treat skin cancer no melanoma concomitant cancer treatment such as chemotherapy, immunotherapy biological modulators, endocrinotherapy, biphosphonates therapy and radiotherapy.