Efficacy and safety of controlled ovarian hyperstimulation with or without letrozole for fertility preservation in breast cancer patients: A multicenter retrospective study

Abstract

IntroductionFertility preservation (FP) is recommended in young breast cancer (BC) patients before (neo)adjuvant treatment. Letrozole-associated controlled ovarian hyperstimulation (LetCOH) is used worldwide to collect mature oocytes for FP, but its efficacy and safety compared to conventional protocols (cCOH) are still debated. AimsTo compare efficacy and safety of FP procedure using LetCOH or cCOH in BC patients in terms of oocyte maturation rate and disease-free survival rates after at least two years of follow-up. MethodsThis multicenter retrospective study compared outcomes of 107 cycles in 97 non-metastatic BC patients aged ≤40 years who underwent cCOH (n = 56) or LetCOH (n = 41) for FP in CHU-Lille and Erasme Hospital, respectively, between December 2012 and January 2017. ResultsPatients and oncological characteristics were similar except for tumor size and HER2 status which were less favorable in the LetCOH group. Patients underwent adjuvant chemotherapy in 96.4% and 48.8% of the cases in cCOH and LetCOH groups, respectively. Hence, 51.2% of LetCOH patients underwent neoadjuvant chemotherapy (p < 0.001). Estradiol peak at ovulation trigger was lower in LetCOH compared to cCOH group while oocyte maturation rates were significantly higher (p < 0.001), without impacting the final number of mature oocytes collected. Seven and four patients relapsed in LetCOH and cCOH groups, respectively, and one patient died in each group after a median follow-up of four years. ConclusionLetCOH is as effective as cCOH for FP. At this time point, there were no safety concerns regarding cCOH in the adjuvant setting but a longer follow-up is warranted.