Oocyte vitrification for fertility preservation following COS does not delay the initiation of neoadjuvant chemotherapy for breast cancer compared to IVM.

Purpose: The objective of the present study was to evaluate whether oocyte vitrification following controlled ovarian stimulation (COS) for fertility preservation (FP) delays the initiation of neoadjuvant chemotherapy (NAC) for breast cancer (BC) as compared to in vitro maturation (IVM).

Methods: We performed a retrospective cohort study including all BC patients eligible for oocyte vitrification following COS or in vitro maturation (IVM) before initiation of NAC between January 2016 and December 2020. The inclusion criteria were female patients aged between 18 and 40, with confirmed non metastatic BC, with indication of NAC, who have had oocyte retrieval for FP after COS, or IVM + / - cryopreservation of ovarian tissue (OTC). Various time points related to cancer diagnosis, FP, or chemotherapy were obtained from a medical record review.

Results: A total of 197 patients with confirmed BC who had oocyte retrieval following COS (n = 57) or IVM + / - OTC (n = 140) for FP prior to NAC were included. Overall, the average time from cancer diagnosis to chemotherapy start was similar between patients having undergone COS or IVM before oocyte vitrification (37.3 ± 13.8 vs. 36. 8 ± 13.5 days; p = 0.89).

Conclusions: The indication of NAC for BC should not be considered as an impediment to urgent COS for oocyte vitrification for FP.