There is no significant difference in preimplantation genetic testing for aneuploidy (pgt-a) outcomes in breast cancer (bc) patients before or after chemotherapy

Use of PGT-A may provide helpful insight on whether FP will be successful for family building and planning in patients (pts) pursuing FP for cancer1. While FP prior to chemotherapy is preferred, some pts cannot complete FP prior to initiating oncologic treatment. Our objective was to evaluate PGT-A outcomes in BC pts who pursued FP before or after chemotherapy. This was a single-center retrospective cohort study of BC pts who pursued FP with PGT-A from 2012-2022 in the setting of a new breast cancer diagnosis (PRE) and those in remission following chemotherapy (POST). Primary outcomes included 1) # eggs retrieved, 2) oocyte maturity rate (# MII oocytes/oocytes retrieved), 3) blast formation rate (# embryos biopsied/2pronuclear zygotes), 4) # embryos biopsied, and 5) euploid embryo rate (# euploid/# biopsied). Secondary outcomes included 1) mosaic (# mosaic/# biopsied) and aneuploid (# aneuploid/# biopsied) embryo rates. Data was analyzed using Mann Whitney U-test and Chi-Square (p<0.05 significant). 42 PRE pts pursued a cumulative 54 in-vitro fertilization (IVF) cycles with PGT-A. 9 POST pts pursued a cumulative 10 IVF cycles with PGT-A. Pts in the PRE group were younger than those in the POST group (PRE: 34.9 ± 4.5; POST: 38.4 ± 3.9 years, p < 0.03). 5 PRE pts were known BRCA carriers at time of stimulation (2 BRCA1 and 3 BRCA2). 1 POST pt was a confirmed BRCA2 carrier. 83.3% (n=35) of PRE pts were nulliparous compared to 77.8% (n=7) in the POST group (p=0.7). All live births (LB) prior to FP were spontaneously conceived in both groups. Median AMH (PRE: 2.5, POST: 1.5 ng/mL; p=0.09), day 2 estradiol levels (PRE: 48.5, POST: 53.7 pg/mL, p=1.0), day 2 follicle-stimulating hormone levels (PRE: 6.6, POST: 7.8 mIU/mL; p=0.3), # stimulation days (PRE: 11, POST: 11 days; p=0.9), and cumulative letrozole dose (PRE: 55, POST: 55 mg; p=0.3) were similar between groups. Utilization of intracytoplasmic sperm injection (ICSI) was 52% (n=28) in the PRE group and 50% (n=5) in the POST group. ICSI was performed in 100% (n=6) of BRCA1/2 carriers. PRE pts had more oocytes retrieved (PRE: 17, POST: 8.5; p<0.04). However, oocyte maturity (PRE: 0.8, POST: 0.8; p=0.9), normal fertilization (PRE: 0.5, POST: 0.6; p=0.9), and blast formation (PRE: 0.7, POST: 0.7; p=0.4) rates were similar. Furthermore, # embryos biopsied was similar between groups (PRE: 5, POST: 2.5 embryos; p=0.049). There was no difference in euploid embryo rate (PRE: 0.4, POST: 0.2, p=0.9), nor with the percent of no euploidy in each group [27% (n=15) PRE and 50% (n=5) POST]. There was also no difference in mosaic (PRE: 0.2, POST: 0; p=0.3) and aneuploid (PRE: 0.3, POST: 0.5; p=0.6) embryo rates. 5 (11.9%) PRE and 4 (44.4%) POST pts pursued subsequent frozen embryo transfers using euploid embryos with 100% LB rate in both groups. 1 pt in PRE and POST groups had 2 LBs and 1 pt in PRE group had 1 LB from a gestational carrier. FP with PGT-A following chemotherapy can be a viable option for breast cancer pts who did not have the opportunity at the time of initial diagnosis.