Response to Ovarian Stimulation for Urgent Fertility Preservation before Gonadotoxic Treatment in BRCA-Pathogenic-Variant-Positive Breast Cancer Patients.

BRCA 1/2 pathogenic variants increase the risk of developing early and aggressive breast cancers (BC). For these patients, fertility potential can be directly affected by oncologic treatments. In addition, evidence indicates that BRCA-mutated women had a significant reduction in their ovarian reserve. In order to improve their chances of conception after the completion of cancer treatments, fertility preservation should be proposed before the administration of gonadotoxic drugs, ideally by oocyte vitrification after controlled ovarian hyperstimulation (COH). The present investigation aims to assess the ovarian response to COH in BRCA 1/2-pathogenic-variant carriers diagnosed with BC. Patient characteristics and COH outcomes were compared between BRCA-positive (n = 54) and BRCA-negative (n = 254) patients. The number of oocytes recovered did not differ between the two groups. However, the oocyte maturation rate and the number of mature oocytes obtained (7 (4.5-11.5) vs. 9 (5-14) oocytes, p = 0.05) were significantly lower in the BRCA-mutated patients. Although individualized COH protocols should be discussed, BRCA-mutated patients would benefit from FP before BC occurs, in order to cope with the potential accelerated decline of their ovarian reserve, optimize the success rate of FP by repeating COH cycles, and to preserve the feasibility of PGT-M by collecting a large amount of eggs.

Should Preimplantation Genetic Testing (PGT) Systematically Be Proposed to BRCA Pathogenic Variant Carriers?

Over the past years, BRCA genes pathogenic variants have been associated to reproductive issues. Indeed, evidence indicate that BRCA-mutated patients are not only at higher risk of developing malignancies, but may also present a reduction of the follicular stockpile. Given these characteristics, BRCA patients may be candidates to fertility preservation (FP) techniques or preimplantation genetic testing (PGT) to avoid the transmission of this inherited situation. Since the success rates of both procedures are highly related to the number of oocytes that could be recovered after ovarian stimulation, predicted by ovarian reserve tests, they are ideally performed before the diagnosis of cancer and its treatment. Despite the specific reproductive challenges related to BRCA status, no international guidelines for the application of PGT and FP in this subgroup of patients is currently available. The present article aims to review the available data regarding BRCA carriers' ovarian reserve and PGT success rates in oncologic and non-oncologic contexts, to determine the actual indication of PGT and further to improve patients' care pathway.