RCT of Fixed vs Titrated Letrozole in Breast Cancer Patient Undergoing IVF

Inclusion Criteria: * Female breast cancer patient with breast cancer diagnosis after surgery and before undergoing chemotherapy desiring fertility preservation with oocyte or embryo cryopreservation * Healthy subject according to documented medical history and physical examination who has been diagnosed with breast cancer (estrogen and progesterone receptor positive and/or negative) * Age less that 45 years at time of informed consent * Verbal or written clearance from medical or surgical oncologist to undergo controlled ovarian hyperstimulation-IVF * Delay to chemotherapy treatment will not jeopardize cancer treatment outcome * Ovarian stimulation will not affect cancer treatment plan * Transvaginal ultrasound scan (US) within one month of starting stimulation with no clinically significant pelvic mass * Serum FSH level (Day 2-4) less than 25 * Negative pregnancy test prior to beginning Letrozole or gonadotropin therapy * Willing and able to comply with the protocol * Voluntary provision of written informed consent, prior to any study related procedure that was not part of normal medical care, with the understanding that the subject can withdraw consent at any time without prejudice to her future medical care * Willingness to provide follow-up information on herself and babies born as part of this study Exclusion Criteria: * Patients not medically cleared by their oncologist * Patients with stage IV breast cancer based on the poor prognosis, general health of the patient…