Impact of BRCA1 and BRCA2 mutations on ovarian reserve and fertility preservation outcomes in young women with breast cancer

Purpose: To determine the impact of BRCA1 and BRCA2 mutations on ovarian reserve and fertility preservation outcome. The main purpose and research question of the study is to determine the impact of BRCA1 and BRCA2 mutations on ovarian reserve and fertility preservation outcomes. Methods: Prospective study: 67 breast cancer patients between 18 and 40 years old, undergoing a fertility preservation by means of oocyte storage were considered. Inclusions criteria for the study were age between 18 and 40 years old, BMI between 18 and 28, breast cancer neoplasm stage I and II according to American Joint Committee on Cancer classification (2017) and no metastasis. Exclusion criteria: age over 40 years old, BMI < 18 and > 28, breast cancer neoplasm stage III and IV and do not performed the BRCA test. A total of 21 patients had not performed the test and were excluded. Patients were divided into four groups: Group A was composed by 11 breast cancer patients with BRCA 1 mutations, Group B was composed by 11 breast cancer patients with BRCA 2 mutations, Group C was composed by 24 women with breast cancer without BRCA mutations, and Group D (control) was composed by 181 normal women. Results: Group A showed significant lower AMH levels compared to Group C and D (1.2 ± 1.1 vs 4.5 ± 4.1 p < 0.05 and 1.2 ± 1.1 vs 3.8 ± 2.5 p < 0.05). BRCA1 mutated patients showed a significant lower rate of mature oocytes (MII) compared to Group C (3.1 ± 2.3 vs 7.2 ± 4.4 p < 0,05) and Group D (3.1 ± 2.3 vs 7.3 ± 3.4; p < 0,05). Breast cancer patients needed a higher dose of gonadotropins compared to controls (Group A 2206 ± 1392 Group B2047.5 ± 829.9 Group C 2106 ± 1336 Group D 1597 ± 709 p < 0,05). No significant differences were found among the groups considering basal FSH levels, duration of stimulation, number of developed follicles, and number of total retrieved oocytes. Regarding BRCA2 mutation, no effect on fertility was shown in this study. Conclusions: The study showed that BRCA1 patients had a higher risk of premature ovarian insufficiency (POI) confirmed by a diminished ovarian reserve and a lower number of mature oocytes suitable for cryopreservation.