Abstract GS3-02: Fertility and ovarian function preservation in premenopausal women with early breast cancer: results from the multicenter prospective PREgnancy and FERtility (PREFER) study

Abstract Background: Oncofertility counseling is standard of care in premenopausal patients (pts) with early breast cancer (EBC) who are candidates to receive chemotherapy (CT). However, limited data exist on the uptake of ovarian function and/or fertility preservation strategies and reasons for refusal. Moreover, for pts undergoing controlled ovarian stimulation (COS) for gamete cryopreservation, the evidence on its safety derives mostly from retrospective studies; thus, some physicians remain concerned in offering this strategy. To address the significant challenges of the oncofertility counseling in premenopausal women with EBC, the PREFER study was developed as a national comprehensive program aiming to optimize care and improve knowledge in this field. Methods: PREFER (NCT02895165) is a multicenter prospective cohort study conducted in 23 Italian centers affiliated to the Gruppo Italiano Mammella (GIM) study group. Eligible pts were premenopausal women aged