Safety of assisted reproductive technologies before and after anticancer treatments in young women with breast cancer: A systematic review and meta-analysis

Abstract Background: Controlled ovarian stimulation (COS) for oocyte/embryo cryopreservation before starting chemotherapy is standard of care for young women with breast cancer wishing to preserve fertility. However, some oncologists remain concerned on the safety of COS, particularly in patients with hormone-sensitive tumors. Moreover, limited evidence exists on the safety of assisted reproductive technologies (ART) in breast cancer survivors after completion of anticancer treatments. Material and methods: A systematic literature review with no date restriction up to June 30, 2021 was conducted to identify studies reporting results of oncological outcomes in breast cancer patients and survivors who underwent COS or other ART compared to patients and survivors who did not access these techniques. From each included study, recurrence ratio, event-free survival (EFS) and mortality rate were extracted. Pooled relative risks (RRs) and hazard ratios (HRs) with 95% confidence intervals (CI) were calculated using the random effects models. Results: Out of 15 included studies (n=4,643), 11 reported outcomes of patients who underwent COS for fertility preservation before starting chemotherapy, and 4 of survivors who underwent ART following anticancer treatment completion. Compared to women who did not receive fertility preservation at diagnosis (n=2,386), those who underwent COS (n=1,594) had reduced risk of recurrence (RR 0.58, 95% CI 0.46-0.73) or mortality (RR 0.54, 95% CI 0.38-0.76). No detrimental effect of COS on EFS was observed (HR 0.76, 95% CI 0.55-1.06). A similar trend of better outcomes in terms of EFS was observed in women with hormone-receptor positive disease who underwent COS (HR 0.36, 95% CI 0.20-0.65).Compared to women not exposed to ART following completion of anticancer treatments (n=540), those exposed to ART (n=123) showed a tendency for better outcomes in terms of recurrence ratio (RR 0.34, 95% CI 0.17-0.70) and EFS (HR 0.43, 95% CI 0.17-1.11). Conclusions: Despite including mostly retrospective studies, this meta-analysis suggests that accessing COS at diagnosis, also in hormone receptor-positive disease, or ART following treatment completion is not associated with detrimental prognostic effect in young women with breast cancer. These results are important to reassure patients and oncologists on the safety of these procedures to increase the chances of future conception. Citation Format: Luca Arecco, Eva Blondeaux, Marco Bruzzone, Marcello Ceppi, Maria Maddalena Latocca, Andrea Boutros, Camilla Marrocco, Maria Grazia Razeti, Maurizio Cosso, Stefano Spinaci, Margherita Condorelli, Claudia Massarotti, Lucia Del Mastro, Isabelle Demeestere, Matteo Lambertini. Safety of assisted reproductive technologies before and after anticancer treatments in young women with breast cancer: A systematic review and meta-analysis [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 PD5-07.