Ovarian tissue cryopreservation in young cancer patients for fertility preservation

Anatomic nomenclature and 3-dimensional regional model of the human ovary: call for a new paradigm

The ovaries are the female gonads that are crucial for reproduction, steroid production, and overall health. Historically, the ovary was broadly divided into regions defined as the cortex, medulla, and hilum. This current nomenclature lacks specificity and fails to consider the significant anatomic variations in the ovary. Recent technological advances in imaging modalities and high-resolution omic analyses have brought about the need for revision of the existing definitions, which will facilitate the integration of generated data and enable the characterization of organ subanatomy and function at the cellular level. The creation of these high-resolution multimodal maps of the ovary will enhance collaboration and communication among disciplines and between clinicians and researchers. Beginning in March 2021, the Pediatric and Adolescent Gynecology Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development invited subject-matter experts to participate in a series of workshops and meetings to standardize ovarian nomenclature and define the organ's features. The goal was to develop a spatially defined and semantically consistent terminology of the ovary to support collaborative, team science-based endeavors aimed at generating reference atlases of the human ovary. The group recommended a standardized, 3-dimensional description of the ovary and an ontological approach to the subanatomy of the ovary and definition of follicles. This new greater precision in nomenclature and mapping will better reflect the ovary's heterogeneous composition and function, support the standardization of tissue collection, facilitate functional analyses, and enable clinical and research collaborations. The conceptualization process and outcomes of the effort, which spanned the better part of 2021 and early 2022, are introduced in this article. The institute and the workshop participants encourage researchers and clinicians to adopt the new systems in their everyday work to advance the overarching goal of improving human reproductive health.

A survey of ovarian reserve and quality of life in female survivors of pediatric cancer

INTRODUCTION

Childhood cancer is rare; the incidence in Sweden is approximately 16 new cases/100 000 children each year. Reduced reproductive function and fertility are well-known side effects of cancer treatment. Anti-Müllerian hormone (AMH) has been shown to correlate well with antral follicle count in healthy women but is currently not recommended as the primary surveillance modality for evaluation of premature ovarian insufficiency in this patient group. Psychological wellbeing related to fertility could affect quality of life and should be included in long-term follow-up. The aim of the study is to present the baseline data from inclusion for a prospective follow-up study of fertility surveillance where both medical and psychological aspects of fertility in female childhood cancer survivors are considered.

MATERIAL AND METHODS

These are the first results from this longitudinal follow-up cohort study. Female adolescent and young adult survivors of pediatric cancer in Western Sweden were included from January 2016 to December 2018, a total of 54 participants. Median age at inclusion was 21 (15-29) years and median age at cancer diagnosis was 10 (1-17) years. AMH levels, antral follicle count, and data on fertility were recorded at inclusion and will be prospectively followed up. The study includes questionnaires and interviews concerning quality of life. This study is planned to continue until the participants reach the age of 40 years.

RESULTS

Eighteen of 54 (33%) participants had AMH levels below 1.0 µg/L and were considered to have high or very high risk of infertility. Median AMH level was 2.50 µg/L. Six women had immediate need of oocyte cryopreservation. Psychological assessment showed that more than one-third of participants (n = 20) had elevated anxiety scores.

CONCLUSIONS

One-third of female survivors of pediatric cancer in the study had high risk of low ovarian reserve, measured by a combination of AMH and antral follicle count, and many had signs of anxiety. The longitudinal study could contribute to better knowledge in the changes of AMH over time for this patient group. Psychological follow-up with questionnaires and interviews evaluating signs of depression and anxiety may serve as a model for future screening programs.

Genomic Consideration in Chemotherapy-Induced Ovarian Damage and Fertility Preservation

Chemotherapy-induced ovarian damage and fertility preservation in young patients with cancer are emerging disciplines. The mechanism of treatment-related gonadal damage provides important information for targeting prevention methods. The genomic aspects of ovarian damage after chemotherapy are not fully understood. Several studies have demonstrated that gene alterations related to follicular apoptosis or accelerated follicle activation are related to ovarian insufficiency and susceptibility to ovarian damage following chemotherapy. This may accelerate follicular apoptosis and follicle reservoir utilization and damage the ovarian stroma via multiple molecular reactions after chemotherapy. This review highlights the importance of genomic considerations in chemotherapy-induced ovarian damage and multidisciplinary oncofertility strategies for providing high-quality care to young female cancer patients.

Molecular Mechanism and Prevention Strategy of Chemotherapy- and Radiotherapy-Induced Ovarian Damage

Fertility preservation is an emerging discipline, which is of substantial clinical value in the care of young patients with cancer. Chemotherapy and radiation may induce ovarian damage in prepubertal girls and young women. Although many studies have explored the mechanisms implicated in ovarian toxicity during cancer treatment, its molecular pathophysiology is not fully understood. Chemotherapy may accelerate follicular apoptosis and follicle reservoir utilization and damage the ovarian stroma via multiple molecular reactions. Oxidative stress and the radiosensitivity of oocytes are the main causes of gonadal damage after radiation treatment. Fertility preservation options can be differentiated by patient age, desire for conception, treatment regimen, socioeconomic status, and treatment duration. This review will help highlight the importance of multidisciplinary oncofertility strategies for providing high-quality care to young female cancer patients.

Advances in the Treatment and Prevention of Chemotherapy-Induced Ovarian Toxicity

Due to improvements in chemotherapeutic agents, cancer treatment efficacy and cancer patient survival rates have greatly improved, but unfortunately gonadal damage remains a major complication. Gonadotoxic chemotherapy, including alkylating agents during reproductive age, can lead to iatrogenic premature ovarian insufficiency (POI), and loss of fertility. In recent years, the demand for fertility preservation has increased dramatically among female cancer patients. Currently, embryo and oocyte cryopreservation are the only established options for fertility preservation in women. However, there is growing evidence for other experimental techniques including ovarian tissue cryopreservation, oocyte in vitro maturation, artificial ovaries, stem cell technologies, and ovarian suppression. To prevent fertility loss in women with cancer, individualized fertility preservation options including established and experimental techniques that take into consideration the patient's age, marital status, chemotherapy regimen, and the possibility of treatment delay should be provided. In addition, effective multidisciplinary oncofertility strategies that involve a highly skilled and experienced oncofertility team consisting of medical oncologists, gynecologists, reproductive biologists, surgical oncologists, patient care coordinators, and research scientists are necessary to provide cancer patients with high-quality care.

Pretreatment of ovaries with collagenase before vitrification keeps the ovarian reserve by maintaining cell-cell adhesion integrity in ovarian follicles

The mammalian ovarian follicle is comprised of the germ cell or oocyte surrounded by the somatic cells, the granulosa and theca cells. The ovarian stroma, including the collagen-rich matrix that supports the three-dimensional disk-like follicular structure, impacts the integrity of the ovarian follicle and is essential for follicular development. Maintaining follicular integrity during cryopreservation has remained a limiting factor in preserving ovarian tissues for transplantation because a significant proportion of developed follicles in the frozen-thawed ovaries undergo atresia after transplantation. In this study, we show for the first time that during vitrification of the mouse ovary, the attachment of the oocyte to the granulosa cells was impaired by the loss of the cadherin adhesion molecules. Importantly, exposure to a high osmotic solution greatly decreased the ratio of oocyte diameter to the diameter of its follicle but did not alter the collagen-rich matrix surrounding the follicles. By treating ovaries briefly with collagenase before exposure to the hyper-osmotic solution the ratio of oocyte diameter to follicle diameter was maintained, and cadherin adhesion junctions were preserved. When frozen-thawed ovaries were transplanted to the bursa of recipient hosts, pretreatment with collagenase significantly increased serum levels of AMH, the number of intact follicles and the total number of viable offspring compared to frozen-thawed ovaries without collagenase pretreatment, even 6 months after transplantation. Thus, the collagenase pretreatment could provide a beneficial approach for maintaining the functions and viability of cryopreserved ovaries in other species and clinically relevant situations.

An evaluation of the Gifu Model in a trial for a new regional oncofertility network in Japan, focusing on its necessity and effects

Purpose

We evaluated our 2-year experience of the regional oncofertility network in Gifu Prefecture (GPOFS) in order to establish a more sophisticated regional oncofertility networking model in Japan.

Methods

Questionnaires were distributed twice in January 2013 to 57 departments in 35 hospitals that provide cancer treatment in Gifu Prefecture, before the establishment of the regional oncofertility network. The number and type of disease of the referred adolescent and young adult (AYA) cancer patients who visited the oncofertility clinic in Gifu University Hospital via the GPOFS were analyzed.

Results

The majority of regional oncologists are aware of the need to provide information about oncofertility to their patients, but they cannot provide sufficient information due to their lack of knowledge about reproductive medicine. Eighty-one AYA patients were referred to our clinic for oncofertility counseling in the first 2 years after the establishment of the GPOFS.

Conclusions

The GPOFS as the first regional oncofertility network in Japan has just started and may be working to help both AYA cancer patients and their oncologists. The nationwide establishment of the regional oncofertility network model could help both AYA cancer patients and oncologists.