Abstract P5-18-05: Long-acting GnRH agonist ovulation trigger to avoid ovarian hyperstimulation and to combine oocyte cryopreservation with ovarian suppression during chemotherapy

Abstract

Abstract Background: Oocyte cryopreservation and gonadal suppression during chemotherapy with long-acting GnRH agonists (GnRHa) are standard fertility preservation (FP) methods in women with breast cancer. When both strategies are accepted by the patient, the first injection of GnRHa is frequently administered few days after oocyte retrieval in order to start oncological therapies as soon as possible. GnRHa suppress gonadal function after an initial stimulation phase due to a gonadotropins surge. Consequently, some cases of ovarian hyperstimulation (OHSS) have been described following GnRHa administration during the luteal phase of an oocyte cryopreservation cycle, as a consequence of the initial flare-up effect on recently stimulated ovaries. OHSS is associated with specific complications, such as an increased thromboembolic risk and a possible delay in the start of chemotherapy. These risks may discourage physicians from proposing gonadal suppression in combination with oocyte cryopreservation, denying women a FP opportunity with proven efficacy. However, since the same flare up effect of short-acting GnRHa (e.g. Triptorelin 0.2 mg) is commonly used to trigger ovulation in high responding infertile patients, we propose the initiation of long-acting GnRHa administration at triggering. Our hypothesis is that by inducing ovulation with long-acting GnRHa we meet the last requirement for oocytes maturation and create suppression by the time patients start chemotherapy, without the need of a further injection in the luteal phase. Methods From 2016 to 2020, 70 consecutive ovarian stimulation cycles for oocyte cryopreservation in oncological patients before chemotherapy were performed in a single university centre. Cycle outcomes were evaluated accordingly to the trigger method. Maturation rate was defined as number of cryopreserved mature oocytes/total number of oocytes retrieved. When the long-acting GnRHa was used for triggering, luteal phase hormones were assessed. Results After controlled ovarian stimulation (COS) with standard or random start antagonist protocol, ten women received the long-acting GnRHa trigger (Decapeptyl 3.75 mg, Ipsen. Group A) 36 hours before oocyte retrieval, 37 received highly purified Chorionic Gonadotrophin (Gonasi HP 10000 UI, IBSA. Group B) and 23 the short-acting GnRHa (Decapeptyl 0.2 mg, Ipsen. Group C). The groups were comparable in terms of demographic and clinical parameters. Median number of mature cryopreserved oocytes in group A was 14 (range 8-22) with a maturation rate of 81% (68-100), versus 9 (0-24) with a maturation rate of 78% (43-100) in group B, and 9 (3-34), 78% (38-100) in group C. There was no case of OHSS in Group A. Two patients developed OHSS after administration of long-acting GnRH in the luteal phase after COS, one in Group B and one in Group C. Five days after oocyte retrieval (7 days after trigger), serum FSH median level in group A was 1.28 mUI/ml (0.48-2.50) and LH median level was 1.04 mUI/ml (0.26-2.46). Conclusion We report for the first time the efficacy of long-acting GnRHa in obtaining mature oocytes and, at the same time, in guaranteeing complete suppression by chemotherapy initiation. We are aware that our data should be confirmed by more robust studies and higher numbers. Nevertheless, the feasibility of this strategy is an important step in reducing the risk of OHSS after ovarian stimulation while giving the opportunity to combine oocyte cryopreservation and ovarian suppression during chemotherapy, with proven efficacy as options to preserve fertility and ovarian function, respectively. Citation Format: Claudia Massarotti, Matteo Lambertini, Sara Stigliani, Fausta Sozzi, Paola Scaruffi, Paola Anserini. Long-acting GnRH agonist ovulation trigger to avoid ovarian hyperstimulation and to combine oocyte cryopreservation with ovarian suppression during chemotherapy [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-18-05.