Primordial follicles remaining in young cancer survivors who received chemotherapy.

Abstract

Ovarian tissue cryopreservation (OTC) is performed for fertility preservation in cancer patients undergoing chemotherapy. Although anti-Müllerian hormone is used as a marker for ovarian reserve, serum levels do not always correlate with the number of follicles. Additionally, the follicle development stage most affected by chemotherapy is unclear. We examined the association between serum anti-Müllerian hormone levels and the number of remaining primordial follicles after chemotherapy, as well as which follicle stage is most affected by chemotherapy before ovarian cryopreservation. Thirty-three patients who underwent OTC were divided into the chemotherapy (n = 22) and non-chemotherapy (n = 11) groups; their ovarian tissues underwent histological examination. Pathological ovarian damage induced by chemotherapy was assessed. Ovarian volumes were estimated from weights. We compared the number of follicles at each developmental stage as a percentage of primordial follicles between the groups. The relationship between serum anti-Müllerian hormone level and primordial follicle density was analyzed. The chemotherapy group had a significantly lower serum anti-Müllerian hormone level, ovarian volume, and density of developing follicles than the non-chemotherapy group. Serum anti-Müllerian hormone levels correlated with primordial follicle density only in the non-chemotherapy group. The chemotherapy group had significantly lower numbers of primary and secondary follicles. Chemotherapy induces ovarian damage and follicle loss. However, serum anti-Müllerian hormone level does not always reflect the number of primordial follicles after chemotherapy, and chemotherapy more significantly affects primary and secondary follicles than primordial follicles. Many primordial follicles remain in the ovary after chemotherapy, supporting OTC for fertility preservation.