Impact of Breast Cancer and Germline BRCA Pathogenic Variants on Fertility Preservation in Young Women

Anti-Müllerian hormone: biology and role in endocrinology and cancers

Anti-Müllerian hormone (AMH) is a peptide belonging to the transforming growth factor beta superfamily and acts exclusively through its receptor type 2 (AMHR2). From the 8th week of pregnancy, AMH is produced by Sertoli cells, and from the 23rd week of gestation, it is produced by granulosa cells of the ovary. AMH plays a critical role in regulating gonadotropin secretion, ovarian tissue responsiveness to pituitary hormones, and the pathogenesis of polycystic ovarian syndrome. It inhibits the transition from primordial to primary follicles and is considered the best marker of ovarian reserve. Therefore, measuring AMH concentration of the hormone is valuable in managing assisted reproductive technologies. AMH was initially discovered through its role in the degeneration of Müllerian ducts in male fetuses. However, due to its ability to inhibit the cell cycle and induce apoptosis, it has also garnered interest in oncology. For example, antibodies targeting AMHR2 are being investigated for their potential in diagnosing and treating various cancers. Additionally, AMH is present in motor neurons and functions as a protective and growth factor. Consequently, it is involved in learning and memory processes and may support the treatment of Alzheimer's disease. This review aims to provide a comprehensive overview of the biology of AMH and its role in both endocrinology and oncology.

Fertility and Pregnancy-Related Issues in Young BRCA Carriers With Breast Cancer

Approximately 10% to 15% of breast cancer cases in young women are diagnosed in patients harbouring germline (g) pathogenic or likely pathogenic variants (PVs) in the BReast CAncer 1 (BRCA1) or BReast CAncer 2 (BRCA2) genes. Preclinical and clinical studies showed a potential negative effect of germline BRCA1/2 (gBRCA1/2) PVs on ovarian reserve and reproductive potential, even before starting anticancer therapies. The aim of this article is to summarize the current literature on the fertility potential of young gBRCA1/2 PVs carriers with breast cancer and the risk of gonadotoxicity associated with anticancer treatments. Moreover, we describe the available evidence on the efficacy of fertility preservation techniques in young gBRCA1/2 PVs carriers and the safety data on having a pregnancy after breast cancer treatment.

BRCA Mutations and Fertility Preservation

Hereditary cancers mostly affect the adolescent and young adult population (AYA) at reproductive age. Mutations in BReast CAncer (BRCA) genes are responsible for the majority of cases of hereditary breast and ovarian cancer. BRCA1 and BRCA2 act as tumor suppressor genes as they are key regulators of DNA repair through homologous recombination. Evidence of the accumulation of DNA double-strand break has been reported in aging oocytes, while BRCA expression decreases, leading to the hypothesis that BRCA mutation may impact fertility. Moreover, patients exposed to anticancer treatments are at higher risk of fertility-related issues, and BRCA mutations could exacerbate the treatment-induced depletion of the ovarian reserve. In this review, we summarized the functions of both genes and reported the current knowledge on the impact of BRCA mutations on ovarian ageing, premature ovarian insufficiency, female fertility preservation strategies and insights about male infertility. Altogether, this review provides relevant up-to-date information on the impact of BRCA1/2 mutations on fertility. Notably, BRCA-mutated patients should be adequately counselled for fertility preservation strategies, considering their higher sensitivity to chemotherapy gonadotoxic effects.