LAUSR

To determine the frequency of hereditary breast cancer associated with different mutated genes and to evaluate fertility preservation (FP) outcomes among young women with hereditary breast cancer when compared to non-hereditary breast cancer. A retrospective cohort study of women with breast cancer who underwent fertility preservation treatment at our academic fertility center between 2005 and 2019. We included all women with breast cancer aged < 40 years who had a genetic testing and underwent fertility preservation before starting gonadotoxic therapy (n = 132). Our objective was to evaluate the total number of oocytes retrieved, mature oocytes MII, embryos (where appropriate), cryopreserved oocytes, and/or embryos. Of 132 women with breast cancer, 40 women were found to be genetically positive (31.4%), 31 women of 40 (77.5%) had a BRCA mutation, 3 (7.5%) had ATM, 2 (5%) had CHK2, and one (2.5%) for each of the following genes: PALP2, NF, MUTYH.c.536A, and TP53. There was no significant difference between the groups in the total number of eggs retrieved and the number of MII oocytes and cryopreserved oocytes. The numbers of fertilized oocytes and cryopreserved embryos in the hereditary (n = 40) and non-hereditary (n = 92) group were (5.15 ± 6.6 vs 2.90 ± 4.2, P = 0.054) and (3.35 ± 3.7 vs 1.9 ± 2.8, P = 0.046) respectively. More than three quarters of positive mutated genes in women with breast cancer are BRCA mutations. Compared to those with non-hereditary breast cancer, women with hereditary breast cancer attained higher number of cryopreserved embryos.