Methods of controlled ovarian stimulation for embryo/oocyte cryopreservation in breast cancer patients

ABSTRACT Introduction: Controlled ovarian stimulation (COS) is a crucial step before oocyte collection and subsequent embryo/oocyte cryopreservation. However, in young breast cancer patients, the need for COS raises specific issues that should be taken into account during oncofertility counseling. Areas covered: We aim to perform an overview of COS protocols with a specific focus on the current knowledge and clinical challenges related to their use in young breast cancer patients. Expert commentary: Many protocols for COS are currently available to induce multiple follicular recruitment and maximize oocyte retrieval in women undergoing in vitro fertilization treatment. In cancer patients, to avoid the need to wait for a spontaneous menstruation, emergency protocols are also available so that COS can be started at any time during the menstrual cycle. COS protocols with the addition of tamoxifen or letrozole have been specifically designed for breast cancer patients to limit the potential negative impact of the temporary increase in estradiol levels during stimulation.