Non-growing follicle density is increased following adriamycin, bleomycin, vinblastine and dacarbazine (ABVD) chemotherapy in the adult human ovary

Abstract

Study question: Do the chemotherapeutic regimens of ABVD (adriamycin, bleomycin, vinblastine and dacarbazine) or OEPA-COPDAC (combined vincristine, etoposide, prednisone, doxorubicin (OEPA) and cyclophosphamide, vincristine, prednisone, dacarbazine (COPDAC)) used to treat Hodgkin lymphoma (HL), affect the density, morphology and in vitro developmental potential of human ovarian follicles? Summary answer: Ovarian tissue from women treated with ABVD contained a higher density of non-growing follicles (NGFs) per cubic millimetre and increased numbers of multiovular follicles but showed reduced in vitro growth compared with patients with lymphoma who had not received chemotherapy, patients treated with OEPA-COPDAC, age-matched healthy women and age-related model-predicted values. What is known already: Chemotherapy regimens can cause a loss of follicles within the ovary that depends on the drugs given. Early stage HL is commonly treated by ABVD, a non-alkylating regimen which apparently has ovarian sparing qualities, thus it is important to investigate the histological appearance and distribution of follicles within ABVD-treated ovarian tissue. Study design, size, duration: Thirteen ovarian biopsies were obtained from HL patients (6 adolescents and 7 adults) and one biopsy from a non-HL patient. Two HL patients and the non-HL patient had received no treatment prior to biopsy collection. The remaining 11 HL patients received one of two regimens; ABVD or OEPA-COPDAC. Tissue was analysed histologically and compared to biopsies from healthy women, and in a sub-group of patients, tissue was cultured for 6 days in vitro. Participants/materials, setting, methods: Ovarian biopsies were obtained from patients undergoing ovarian cryopreservation for fertility preservation, and from healthy women at the time of Caesarian section (‘obstetric tissue’). Follicle number and maturity were evaluated in sections of ovarian cortical tissue, and compared to an age-related model of mean follicle density and to age-matched contemporaneous biopsies. The developmental potential of follicles was investigated after 6 days tissue culture. Main results and the role of chance: A total of 6877 follicles was analysed. ABVD-treated tissue contained a higher density of non-growing follicles/mm3 (230±17) (mean±SEM) than untreated (110±54), OEPA-COPDAC-treated (50±27 and obstetric tissue (20±4)(P< 0.01),with follicle density 9-21 standard deviations higher than predicted by an age-related model. Bi-ovular and binucleated non-growing follicles occurred frequently in ABVD-treated and in adolescent untreated tissue but were not observed in OEPA-COPDAC-treated or obstetric tissue, although OEPA-COPDAC-treated tissue contained a high proportion of morphologically abnormal oocytes (52% versus 23% in untreated, 22% in ABVD-treated and 25% in obstetric tissue; P< 0.001). Activation of follicle growth in vitro occurred in all groups, but in ABVD-treated samples there was very limited development to the secondary stage, whilst in untreated samples from lymphoma patients growth was similar to that observed in obstetric tissue (untreated; P< 0.01 versus ABVD-treated, ns versus obstetric). Large scale data: N/A Limitations, reasons for caution: Although a large number of follicles were analysed, these data were derived from a small number of biopsies. The mechanisms underpinning these observations have yet to be determined and it is unclear how they relate to future fertility. Wider implications of the findings: This study confirms that the number of NGFs is not depleted following ABVD treatment, consistent with clinical data that female fertility is preserved. Our findings demonstrate that immature follicle density can increase as well as decrease following at least one chemotherapy treatment. This is the first report of morphological and follicle developmental similarities between ABVD-treated tissue and the immature human ovary. Further experiments will investigate the basis for the marked increase in follicle density in ABVD-treated tissue.