A review of 15 years of ovarian tissue bank activities

A case of non-Hodgkin lymphoma of the upper gingiva with minimal residual disease detected in cryopreserved ovarian tissue: A case report

Recently, more than 200 live births following ovarian tissue cryopreservation (OTC) and transplantation in cancer survivors have been reported worldwide. However, cancer survivors with minimal residual disease (MRD) in cryopreserved ovarian tissue are at the risk of relapse through the graft. Here, we report a rare case of a 19-year-old female patient with non-Hodgkin lymphoma who had MRD in the ovary harvested for OTC. The patient was diagnosed with aggressive B-cell lymphoma after gingival biopsy. The 18F-fluoro-2-deoxy-D-glucose positron emission tomography scan performed before OTC showed no viable lesions in either ovary. However, on histological evaluation, we detected infiltration of lymphoma cells in the ovary. Informed consent about MRD is required even if there is no evidence of MRD in the ovary before OTC. Patients whose cryopreserved ovaries have MRD may require the development of alternative assisted reproductive technologies such as in vitro growth or artificial ovary.

Comparison of liquid nitrogen-free slow freezing protocols toward enabling a practical option for centralized cryobanking of ovarian tissue

Geographically distributed ovarian tissue cryobanks remain limited due to the high facility and staff costs, and cold transportation to centers is associated with ischemia-induced tissue damage that increases with transport distance. It is ideal to perform the cryopreservation procedure at a tissue removal site or local hospital before shipment to cost-effective centralized cryobanks. However, conventional liquid nitrogen-based freezers are not portable and require expensive infrastructure. To study the possibility of an ovarian tissue cryopreservation network not dependent on liquid nitrogen, we cryopreserved bovine ovarian tissue using three cooling techniques: a controlled rate freezer using liquid nitrogen, a liquid nitrogen-free controlled rate freezer, and liquid nitrogen-free passive cooling. Upon thawing, we evaluated a panel of viability metrics in frozen and fresh groups to examine the potency of the portable liquid nitrogen-free controlled and uncontrolled rate freezers in preserving the ovarian tissue compared to the non-portable conventional controlled rate freezer. We found similar outcomes for reactive oxygen species (ROS), total antioxidant capacity (TAC), follicular morphology, tissue viability, and fibrosis in the controlled rate freezer groups. However, passive slow cooling was associated with the lowest tissue viability, follicle morphology, and TAC, and the highest tissue fibrosis and ROS levels compared to all other groups. A stronger correlation was found between follicle morphology, ovarian tissue viability, and fibrosis with the TAC/ROS ratio compared to ROS and TAC alone. The current study undergirds the possibility of centralized cryobanks using a controlled rate liquid nitrogen-free freezer to prevent ischemia-induced damage during ovarian tissue shipment.

Comparative effects of a calcium chelator (BAPTA-AM) and melatonin on cryopreservation-induced oxidative stress and damage in ovarian tissue

Oncology treatments cause infertility, and ovarian tissue cryopreservation and transplantation (OTCT) is the only option for fertility preservation in prepubertal girls with cancer. However, OTCT is associated with massive follicle loss. Here, we aimed to determine the effect of supplementation of slow freezing and vitrification media with BAPTA-AM and melatonin alone and in combination on ovarian tissue viability, reactive oxygen species (ROS) levels, total antioxidant capacity (TAC), and follicular morphology and viability. Our results indicated that BAPTA-AM and melatonin can significantly improve ovarian tissue viability and the TAC/ROS ratio and reduce ROS generation in frozen-thawed ovarian tissues in slow freezing and vitrification procedures. BAPTA-AM was also found to be less effective on TAC compared to melatonin in vitrified ovarian tissue. While supplementation of slow freezing and vitrification media with BAPTA-AM and/or melatonin could increase the percentage of morphologically intact follicles in cryopreserved ovarian tissues, the differences were not significant. In conclusion, supplementation of cryopreservation media with BAPTA-AM or melatonin improved the outcome of ovarian tissue cryopreservation in both vitrification and slow freezing methods. Our data provide some insight into the importance of modulating redox balance and intracellular Ca2+ levels during ovarian tissue cryopreservation to optimize the current cryopreservation methods.

Cryostorage of human ovarian tissue: evaluating the storage and disposal pattern over a 22-year period in 2475 patients

RESEARCH QUESTION

What are the parameters of age, indications for ovarian tissue cryopreservation, storage characteristics and reasons for tissue disposal in a large cohort of individuals undertaking cryopreservation?

DESIGN

The relevant parameters in a single university centre were revised and digitalized in the period from 2019 to 2021. To assess patients' motivation at the end of storage, patients were contacted by letter, e-mails and telephone calls.

RESULTS

A group of 2475 patients with stored ovarian tissue were analysed in the time period between 2000 and 2021; the response rate for contact calls and letters was 28.8% (224/777). Where storage had ended (n = 1155), patients had on average stored for 3.8 years and begun storing at age 30 years; the main indications were breast cancer (53%) and lymphoma (17.5%). Of these participants, 2.5% had a transplantation on site, 10.3% transferred their tissue to another cryobank and 11.5% were deceased. The majority of the group (75.7%) ended their storage due to pregnancy (49.1%), a lack of desire to have children (25.9%), storage fees that were too expensive (8.9%), death (8.5%), recurrence of cancer (8.5%), lack of a partner (4%) and fear of surgery in the future (3.1%); 6.7% retrospectively regretted ending storage.

CONCLUSIONS

The pregnancy rate of 49.1%, resulting from ovarian tissue that was not removed during surgery for scheduled ovarian tissue cryopreservation supports the clinical approach of removing and cryopreserving only 25-50% of one ovary. It is proposed that interdisciplinary counselling should be implemented not only prior to fertility preservation, but also when intending to end storage.

The Aging Ovary and the Tales Learned Since Fetal Development

BACKGROUND

While the term "aging" implies a process typically associated with later life, the consequences of ovarian aging are evident by the time a woman reaches her forties, and sometimes earlier. This is due to a gradual decline in the quantity and quality of oocytes which occurs over a woman's reproductive lifespan. Indeed, the reproductive potential of the ovary is established even before birth, as the proper formation and assembly of the ovarian germ cell population during fetal life determines the lifetime endowment of oocytes and follicles. In the ovary, sophisticated molecular processes have been identified that regulate the timing of ovarian aging and these are critical to ensuring follicular maintenance.

SUMMARY

The mechanisms thought to contribute to overall aging have been summarized under the term the "hallmarks of aging" and include such processes as DNA damage, mitochondrial dysfunction, telomere attrition, genomic instability, and stem cell exhaustion, among others. Similarly, in the ovary, molecular processes have been identified that regulate the timing of ovarian aging and these are critical to ensuring follicular maintenance. In this review, we outline critical processes involved in ovarian aging, highlight major achievements for treatment of ovarian aging, and discuss ongoing questions and areas of debate.

KEY MESSAGES

Ovarian aging is recognized as what may be a complex process in which age, genetics, environment, and many other factors contribute to the size and depletion of the follicle pool. The putative hallmarks of reproductive aging outlined herein include a diversity of plausible processes contributing to the depletion of the ovarian reserve. More research is needed to clarify if and to what extent these putative regulators do in fact govern follicle and oocyte behavior, and how these signals might be integrated in order to control the overall pattern of ovarian aging.

Importance of oxygen tension in human ovarian tissue in vitro culture

STUDY QUESTION

Is there any difference between 20% and 5% oxygen (O2) tension in vitro culture (IVC) on the viability and quality of human follicles contained in cultured ovarian cortex?

SUMMARY ANSWER

An O2 tension of 5% yields higher follicle viability and quality than does 20% O2 tension after 6 days of IVC.

WHAT IS KNOWN ALREADY

The primordial follicle (PMF) pool resides within the ovarian cortex, where the in vivo O2 tension ranges between 2% and 8%. Some studies suggest that lowering O2 tension to physiological levels may improve in vitro follicle quality rates.

STUDY DESIGN, SIZE, DURATION

This prospective experimental study included frozen-thawed ovarian cortex from six adult patients (mean age: 28.5 years; age range: 26-31 years) who were undergoing laparoscopic surgery for non-ovarian diseases. Ovarian cortical fragments were cultured for 6 days at (i) 20% O2 with 5% CO2 and (ii) 5% O2 with 5% CO2. Non-cultured fragments served as controls.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Cortical fragments were used for the following analyses: hematoxylin and eosin staining for follicle count and classification; Ki67 staining to evaluate PMF proliferation; cleaved caspase-3 immunostaining to identify follicle apoptosis; 8-hydroxy-2-deoxyguanosine and gamma-H2AX (γH2AX) immunolabeling to detect oxidative stress damage and DNA double-strand breaks (DSBs) in oocytes and granulosa cells (GCs); and β-galactosidase staining to assess follicle senescence. Droplet digital PCR was also performed to further explore the gene expression of superoxide dismutase 2 (SOD2) and glutathione peroxidase 4 (GPX4) from the antioxidant defense system and cyclin-dependent kinase inhibitors (p21 and p16) as tissue senescence-related genes.

MAIN RESULTS AND THE ROLE OF CHANCE

Apoptosis (P = 0.002) and follicle senescence (P < 0.001) rates were significantly lower in the 5% O2 group than in the 20% O2 group. Moreover, GCs in follicles in the 20% O2 group exhibited significantly (P < 0.001) higher oxidative stress damage rates than those in the 5% O2 group. DNA DSB damage rates in GCs of follicles were also significantly higher (P = 0.001) in the 20% O2 group than in the 5% O2 group. SOD2 expression was significantly greater in the 5% O2 group compared to the 20% O2 group (P = 0.04) and the non-cultured group (P = 0.002). Expression of p21 was significantly increased in both the 20% O2 (P = 0.03) and 5% O2 (P = 0.008) groups compared to the non-cultured group. Moreover, the 20% O2 group showed significantly greater p16 expression (P = 0.04) than the non-cultured group, while no significant variation was observed between the 5% O2 and no culture groups.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

This study focuses on improving follicle outcomes during the first step of ovarian tissue IVC, where follicles remain in situ within the tissue. The impact of O2 tension in further steps, such as secondary follicle isolation and maturation, was not investigated here.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that 5% O2 tension culture is a promising step toward potentially solving the problem of poor follicle viability after IVC.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grants from the Fonds National de la Recherche Scientifique de Belgique (FNRS-PDR T.0064.22, CDR J.0063.20 and grant 5/4/150/5 awarded to M.M.D.). The authors have nothing to disclose.

When to cryopreserve ovarian tissue: Determining the effects of chemotherapy on the ovarian reserve by studying follicular density and apoptosis

OBJECTIVES

Patients scheduled to receive chemotherapy should be counselled on fertility preservation. Known gonadotoxic chemotherapies such as alkylating agents have a high risk of altering ovarian reserve. In some cases, the urgency of treatment requires the use of chemotherapy before fertility preservation, which will be carried out at a later stage. Usually the ovarian tissue is cryopreserved. The aim of our study is to investigate the impact of chemotherapies on follicular density and the apoptosis of reserve follicles.

METHODS

We included 140 patients: 63 patients, mean age 18.8 years, were included in the group "no chemotherapy" (group A) and 77 patients, mean age 17.1 years, in the group "received chemotherapy before ovarian conservation" (group B). None of the patients had had pelvic radiotherapy prior to ovarian cryopreservation. The histological parameters studied were follicular density and the presence of malignant cells. We selected 12 patients from group A and 15 patients from group B, comparable in age and pathology, for whom we evaluated follicle apoptosis by immunostaining cleaved caspase-3.

RESULTS

We demonstrated an inverse relationship between follicular density and age (p < 0.0001), as well as a lack of effect of chemotherapy on follicular density (p = 0.87). We showed the impact of various chemotherapies, especially with alkylating agents, on the apoptosis of ovarian follicles (p < 0.0001). Three patients had ovarian tissue infiltration, two of which were malignant.

CONCLUSION

This work underlines the fact that conservation of ovarian tissue after chemotherapy remains possible.

Follicle outcomes in human ovarian tissue: effect of freezing, culture, and grafting

OBJECTIVE

To study the effect of freezing, in vitro culture (IVC) and grafting to chorioallantoic membrane (CAM) on follicle outcomes in human ovarian tissue.

DESIGN

An experimental study.

SETTING

University-based research laboratory.

PATIENTS

Fresh and cryopreserved ovarian tissue from 10 patients was donated to research with their consent and institutional review board approval.

INTERVENTIONS

Fresh and frozen-thawed ovarian cortical pieces were in vitro-cultured and compared (fresh-IVC vs FT-IVC). The FT-IVC fragments were then examined against fragments grafted to CAM (FT-CAM). After both IVC and CAM grafting, ovarian cortical pieces (4×2×1 mm³) were analyzed on days 0, 1, and 6.

MAIN OUTCOME MEASURES

Follicle analyses included histology (count and classification) and immunohistochemistry (Ki67 [proliferation], caspase-3 [apoptosis], 1A and 1B light chain 3B [autophagy], p-Akt, FOXO1, and p-rpS6 [PI3K activation]). Droplet digital polymerase chain reaction further explored expression of PI3K pathway- and oocyte-related genes in tissue sections.

RESULTS

No major differences were detected between fresh-IVC and FT-IVC tissues in any conducted analyses. Although a significant drop was observed in primordial follicle (PF) proportions in the fresh-IVC and FT-IVC groups (d0 vs. d6, P<.002), they held steady in the FT-CAM group (d0 vs. d6, P>.05). The PF rates were also significantly higher in the FT-CAM group than the FT-IVC group on d6 (P=.02). Importantly, avian erythrocytes were already present in 30% of implants from d1. Apoptotic and autophagic follicle rates increased during IVC (P<.008), but remained significantly lower in the FT-CAM group (P<.01), confirming superior follicle preservation in CAM-grafted tissue. Upregulation of the PI3K/FOXO pathway was established in the IVC groups, demonstrating PF activation, whereas significant pathway downregulation was detected in the FT-CAM group (P<.03). The droplet digital polymerase chain reaction tests confirmed oocyte growth during IVC and follicle autophagy in all groups; however, the PI3K pathway appeared to be differentially modulated in tissues and follicles.

CONCLUSIONS

In vitro culture induces PF depletion with no additional impact of freezing. Grafting to CAM preserves the PF pool by curbing follicle activation, apoptosis, and autophagy, probably thanks to rapid graft revascularization and/or the circulating embryonic antimüllerian hormone. These findings highlight the importance of enhancing neoangiogenesis in ovarian grafts and investigating the potential benefits of administering antimüllerian hormone to prevent PF burnout.

What should be done in terms of fertility preservation for patients with cancer? The French 2021 guidelines

AIM

To provide practice guidelines about fertility preservation (FP) in oncology.

METHODS

We selected 400 articles after a PubMed review of the literature (1987-2019).

RECOMMENDATIONS

Any child, adolescent and adult of reproductive age should be informed about the risk of treatment gonadotoxicity. In women, systematically proposed FP counselling between 15 and 38 years of age in case of treatment including bifunctional alkylating agents, above 6 g/m2 cyclophosphamide equivalent dose (CED), and for radiation doses on the ovaries ≥3 Gy. For postmenarchal patients, oocyte cryopreservation after ovarian stimulation is the first-line FP technique. Ovarian tissue cryopreservation should be discussed as a first-line approach in case of treatment with a high gonadotoxic risk, when chemotherapy has already started and in urgent cases. Ovarian transposition is to be discussed prior to pelvic radiotherapy involving a high risk of premature ovarian failure. For prepubertal girls, ovarian tissue cryopreservation should be proposed in the case of treatment with a high gonadotoxic risk. In pubertal males, sperm cryopreservation must be systematically offered to any male who is to undergo cancer treatment, regardless of toxicity. Testicular tissue cryopreservation must be proposed in males unable to cryopreserve sperm who are to undergo a treatment with intermediate or severe risk of gonadotoxicity. In prepubertal boys, testicular tissue preservation is: - recommended for chemotherapy with a CED ≥7500 mg/m2 or radiotherapy ≥3 Gy on both testicles. - proposed for chemotherapy with a CED ≥5.000 mg/m2 or radiotherapy ≥2 Gy. If several possible strategies, the ultimate choice is made by the patient.

Age-related fertility decline: is there a role for elective ovarian tissue cryopreservation?

Age-related fertility decline (ARFD) is a prevalent concern amongst western cultures due to the increasing age of first-time motherhood. Elective oocyte and embryo cryopreservation remain the most established methods of fertility preservation, providing women the opportunity of reproductive autonomy to preserve their fertility and extend their childbearing years to prevent involuntary childlessness. Whilst ovarian cortex cryopreservation has been used to preserve reproductive potential in women for medical reasons, such as in pre- or peripubertal girls undergoing gonadotoxic chemotherapy, it has not yet been considered in the context of ARFD. As artificial reproductive technology (ART) and surgical methods of fertility preservation continue to evolve, it is a judicious time to review current evidence and consider alternative options for women wishing to delay their fertility. This article critically appraises elective oocyte cryopreservation as an option for women who use it to mitigate the risk of ARFD and introduces the prospect of elective ovarian cortex cryopreservation as an alternative.

Fresh and cryopreserved ovarian tissue transplantation for preserving reproductive and endocrine function: a systematic review and individual patient data meta-analysis

BACKGROUND

Ovarian tissue cryopreservation involves freezing and storing of surgically retrieved ovarian tissue in liquid or vapour nitrogen below -190°C. The tissue can be thawed and transplanted back with the aim of restoring fertility or ovarian endocrine function. The techniques for human ovarian tissue freezing and transplantation have evolved over the last 20 years, particularly in the context of fertility preservation in pre-pubertal cancer patients. Fresh ovarian tissue transplantation, using an autograft or donor tissue, is a more recent development; it has the potential to preserve fertility and hormonal function in women who have their ovaries removed for benign gynaecological conditions. The techniques of ovarian tissue cryopreservation and transplantation have progressed rapidly since inception; however, the evidence on the success of this intervention is largely based on case reports and case series.

OBJECTIVE AND RATIONALE

The aim of this study was to systematically review the current evidence by incorporating study-level and individual patient-level meta-analyses of women who received ovarian transplants, including frozen-thawed transplant, fresh or donor graft.

SEARCH METHODS

The review protocol was registered with PROSPERO (CRD42018115233). A comprehensive literature search was performed using MEDLINE, EMBASE, CINAHL and Cochrane Central Register of Controlled Trials from database inception to October 2020. Authors were also contacted for individual patient data if relevant outcomes were not reported in the published manuscripts. Meta-analysis was performed using inverse-variance weighting to calculate summary estimates using a fixed-effects model.

OUTCOMES

The review included 87 studies (735 women). Twenty studies reported on ≥5 cases of ovarian transplants and were included in the meta-analysis (568 women). Fertility outcomes included pregnancy, live birth and miscarriage rates, and endocrine outcomes included oestrogen, FSH and LH levels. The pooled rates were 37% (95% CI: 32-43%) for pregnancy, 28% (95% CI: 24-34%) for live birth and 37% (95% CI: 30-46%) for miscarriage following frozen ovarian tissue transplantation. Pooled mean for pre-transplant oestrogen was 101.6 pmol/l (95% CI: 47.9-155.3), which increased post-transplant to 522.4 pmol/l (95% CI: 315.4-729; mean difference: 228.24; 95% CI: 180.5-276). Pooled mean of pre-transplant FSH was 66.4 IU/l (95% CI: 52.8-84), which decreased post-transplant to 14.1 IU/l (95% CI: 10.9-17.3; mean difference 61.8; 95% CI: 57-66.6). The median time to return of FSH to a value <25 IU/l was 19 weeks (interquartile range: 15-26 weeks; range: 0.4-208 weeks). The median duration of graft function was 2.5 years (interquartile range: 1.4-3.4 years; range: 0.7-5 years). The analysis demonstrated that ovarian tissue cryopreservation and transplantation could restore reproductive and hormonal functions in women. Further studies with larger samples of well-characterized populations are required to define the optimal retrieval, cryopreservation and transplantation processes.

WIDER IMPLICATIONS

Ovarian tissue cryopreservation and transplantation may not only be effective in restoring fertility but also the return of reproductive endocrine function. Although this technology was developed as a fertility preservation option, it may have the scope to be considered for endocrine function preservation.

A comparison of fertility preservation outcomes in patients who froze oocytes, embryos, or ovarian tissue for medically indicated circumstances: a systematic review and meta-analysis

OBJECTIVE

To compare obstetric outcomes in patients cryopreserving reproductive cells or tissues before gonadotoxic therapy.

DESIGN

A literature search was conducted following PRISMA guidelines on Embase, Medline, and Web of Science. Studies reporting obstetric outcomes in cancer patients who completed cryopreservation of oocyte, embryo, or ovarian tissue were included.

SETTING

Not applicable.

PATIENT(S)

Cancer patients attempting pregnancy using cryopreserved cells or tissues frozen before cancer therapy.

INTERVENTION(S)

Oocyte, embryo, or ovarian tissue cryopreservation for fertility preservation in cancer.

MAIN OUTCOME MEASURE(S)

The total numbers of clinical pregnancies, live births, and miscarriages in women attempting pregnancy using cryopreserved reproductive cells or tissues were calculated. A meta-analysis determined the effect size of each intervention.

RESULT(S)

The search returned 4,038 unique entries. Thirty-eight eligible studies were analyzed. The clinical pregnancy rates were 34.9%, 49.0%, and 43.8% for oocyte, embryo, and ovarian tissue cryopreservation, respectively. No significant differences were found among groups. The live birth rates were 25.8%, 35.3%, and 32.3% for oocyte, embryo, and ovarian tissue cryopreservation, respectively, with no significant differences among groups. The miscarriage rates were 9.2%, 16.9%, and 7.5% for oocyte, embryo, and ovarian tissue cryopreservation, respectively. Significantly fewer miscarriages occurred with ovarian tissue cryopreservation than with embryo cryopreservation.

CONCLUSION(S)

This enquiry is required to counsel cancer patients wishing to preserve fertility. Although the limitations of this study include heterogeneity, lack of quality studies, and low utilization rates, it serves as a starting point for comparison of reproductive and obstetric outcomes in patients returning for family-planning after gonadotoxic therapy.

A Systematic Review of Ovarian Tissue Transplantation Outcomes by Ovarian Tissue Processing Size for Cryopreservation

Ovarian tissue cryopreservation (OTC) is the only pre-treatment option currently available to preserve fertility for prepubescent girls and patients who cannot undergo ovarian stimulation. Currently, there is no standardized method of processing ovarian tissue for cryopreservation, despite evidence that fragmentation of ovaries may trigger primordial follicle activation. Because fragmentation may influence ovarian transplant function, the purpose of this systematic review was (1) to identify the processing sizes and dimensions of ovarian tissue within sites around the world, and (2) to examine the reported outcomes of ovarian tissue transplantation including, reported duration of hormone restoration, pregnancy, and live birth. A total of 2,252 abstracts were screened against the inclusion criteria. In this systematic review, 103 studies were included for analysis of tissue processing size and 21 studies were included for analysis of ovarian transplantation outcomes. Only studies where ovarian tissue was cryopreserved (via slow freezing or vitrification) and transplanted orthotopically were included in the review. The size of cryopreserved ovarian tissue was categorized based on dimensions into strips, squares, and fragments. Of the 103 studies, 58 fertility preservation sites were identified that processed ovarian tissue into strips (62%), squares (25.8%), or fragments (31%). Ovarian tissue transplantation was performed in 92 participants that had ovarian tissue cryopreserved into strips (n = 51), squares (n = 37), and fragments (n = 4). All participants had ovarian tissue cryopreserved by slow freezing. The pregnancy rate was 81.3%, 45.5%, 66.7% in the strips, squares, fragment groups, respectively. The live birth rate was 56.3%, 18.2%, 66.7% in the strips, squares, fragment groups, respectively. The mean time from ovarian tissue transplantation to ovarian hormone restoration was 3.88 months, 3.56 months, and 3 months in the strips, squares, and fragments groups, respectively. There was no significant difference between the time of ovarian function' restoration and the size of ovarian tissue. Transplantation of ovarian tissue, regardless of its processing dimensions, restores ovarian hormone activity in the participants that were reported in the literature. More detailed information about the tissue processing size and outcomes post-transplant are required to identify a preferred or more successful processing method.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk], identifier [CRD42020189120].

Fertility Preservation: How to Preserve Ovarian Function in Children, Adolescents and Adults

Chemotherapy, pelvic radiotherapy and ovarian surgery have known gonadotoxic effects that can lead to endocrine dysfunction, cessation of ovarian endocrine activity and early depletion of the ovarian reserve, causing a risk for future fertility problems, even in children. Important determinants of this risk are the patient’s age and ovarian reserve, type of treatment and dose. When the risk of premature ovarian insufficiency is high, fertility preservation strategies must be offered to the patient. Furthermore, fertility preservation may sometimes be needed in conditions other than cancer, such as in non-malignant diseases or in patients seeking fertility preservation for personal reasons. Oocyte and/or embryo vitrification and ovarian tissue cryopreservation are the two methods currently endorsed by the American Society for Reproductive Medicine, yielding encouraging results in terms of pregnancy and live birth rates. The choice of one technique above the other depends mostly on the age and pubertal status of the patient, and personal and medical circumstances. This review focuses on the available fertility preservation techniques, their appropriateness according to patient age and their efficacy in terms of pregnancy and live birth rates.

Assessing the use of tumor-specific DARPin-toxin fusion proteins for ex vivo purging of cancer metastases from human ovarian cortex before autotransplantation

OBJECTIVE

To assess the use of tumor-specific designed ankyrin repeat proteins (DARPins) fused to a domain of Pseudomonas aeruginosa exotoxin A for purging of cancer metastases from the ovarian cortex.

DESIGN

Experimental study.

SETTING

University medical center.

PATIENT(S)

Human ovarian cortex.

INTERVENTION(S)

Ovarian cortex harboring artificially induced breast cancer metastases was treated with DARPins targeted to epithelial cell adhesion molecule (EpCAM) and human epidermal growth factor receptor 2 (HER2).

MAIN OUTCOME MEASURE(S)

The presence of any remaining cancer cells after purging was analyzed by (immuno)histochemistry and reverse transcriptase polymerase chain reaction. Effects on the viability of the ovarian cortex were determined by (immuno)histology, a follicular viability assay, and an assay to determine the in vitro growth capacity of small follicles.

RESULT(S)

After purging with EpCAM-targeted DARPin, all EpCAM-positive breast cancer cells were eradicated from the ovarian cortex. Although treatment had no effect on the morphology or viability of small follicles, a sharp decrease in oocyte viability during in vitro growth was observed, presumably due to low-level expression of EpCAM on oocytes. The HER2-targeted DARPins had no detrimental effects on the morphology, viability, or in vitro growth of small follicles. HER2-positive breast cancer foci were fully eliminated from the ovarian cortex, and the reverse transcriptase polymerase chain reaction showed a decrease to basal levels of HER2 mRNA after purging.

CONCLUSION(S)

Purging cancer metastases from ovarian cortex without impairing ovarian tissue integrity is possible by targeting tumor cell surface proteins with exotoxin A-fused DARPins. By adapting the target specificity of the cytotoxic DARPin fusions, it should be possible to eradicate metastases from all types of malignancies.

Ovarian tissue cryopreservation and transplantation in patients with central nervous system tumours

STUDY QUESTION

Is there a possibility of reseeding cancer cells potentially present in frozen ovarian tissue from patients with central nervous system (CNS) tumours?

SUMMARY ANSWER

Malignancy reseeding in cryopreserved ovarian tissue from 20 patients with CNS tumours was not detected by histology, immunohistochemistry (IHC), molecular biology or xenotransplantation.

WHAT IS KNOWN ALREADY

Ovarian metastasis potential has been documented in patients with leukaemia, borderline ovarian tumours, advanced breast cancer and Ewing sarcoma. However, data on the safety of transplanting frozen-thawed ovarian tissue from cancer patients with CNS tumours are still lacking.

STUDY DESIGN, SIZE, DURATION

This prospective experimental study was conducted in an academic gynaecology research laboratory using cryopreserved ovarian cortex from 20 patients suffering from CNS tumours. Long-term (5 months) xenografting was performed in immunodeficient mice.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Subjects enrolled in the study were suffering from one of six types of CNS tumours including medulloblastoma, ependymoma, primitive neuroectodermal tumours, astrocytoma, glioblastoma and germinoma. The presence of malignant cells was investigated with disease-specific markers for each patient in cryopreserved and xenografted ovarian tissue by histology, IHC via expression of neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP), and reverse transcription droplet digital polymerase chain reaction (RT-ddPCR) for quantification of GFAP and ENO2 gene amplification.

MAIN RESULTS AND THE ROLE OF CHANCE

Serial sections of cryopreserved and xenografted ovarian tissue from 20 patients showed no malignant cells by histology. All samples were negative for NSE and GFAP, although these neural markers were expressed extensively in the patients' primary tumours. Analysis by RT-ddPCR revealed no cancer cells detected in cryopreserved and xenografted ovarian fragments from subjects with astrocytoma, ependymoma, glioblastoma or medulloblastoma. Taken together, the study found no evidence of malignancy seeding in frozen-thawed and xenotransplanted ovarian tissue from patients affected by CNS cancers.

LIMITATIONS, REASONS FOR CAUTION

This analysis cannot guarantee complete elimination of disseminated disease from all cryopreserved ovarian cortex, since we are unable to examine the fragments used for transplantation.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study to be conducted in patients with CNS cancers undergoing ovarian tissue cryopreservation and transplantation, and clearly demonstrates no tumour seeding in their frozen-thawed and xenografted tissue. This information is vital for doctors to provide patients with meaningful and accurate advice on the possibilities and risks of ovarian tissue reimplantation.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grants from the Fonds National de la Recherche Scientifique de Belgique-the Excellence of Science (FNRS-EOS), number 30443682 awarded to M.-M.D. and T.Y.T.N., FNRS grant number 5/4/150/5 and FNRS-PDR Convention grant number T.0077.14 awarded to M.-M.D., grant 2018-042 from the Foundation Against Cancer awarded to A.C., and private donations (Ferrero, de Spoelberch). The authors declare no competing financial interests.

TRIAL REGISTRATION NUMBER

N/A.

Long-time low-temperature transportation of human ovarian tissue before cryopreservation

RESEARCH QUESTION

Can the low-temperature transport time of removed human ovarian tissue be prolonged until cryopreservation?

DESIGN

Fresh ovarian cortex from nine premenopausal patients was either slow-frozen immediately or stored at 4°C for 24 or 48 h before slow-freezing. The fresh and frozen-thawed biopsies were evaluated by follicle counting via calcein staining, histologic analyses via haematoxylin and eosin staining, and apoptosis via terminal deoxynucleotidyl transferase-mediated dUDP nick-end labelling (TUNEL). The fresh cortex was assessed by reactive oxygen species (ROS) and total antioxidant capacity (TAC) assay to detect oxidative stress. The frozen-thawed cortex biopsies were also evaluated by quantitative PCR for messenger RNA (mRNA) expression of BCL-2, BAX, TNFa, HIF-1a, BMP15 and GDF9, and Western blot for detection of BCL-2, BMP15, GDF9 and CASPASE-3. The frozen-thawed cortex was cultured in vitro for 4 days, anti-Müllerian hormone and glucose were assessed in the supernatant, and ROS and TAC assay detected any oxidative stress in the cortex.

RESULTS

In the fresh cortex, there were no significant differences between the three groups. In the frozen-thawed cortex, there were no significant differences between the three groups regarding follicle viability, TUNEL, mRNA expression of TNFa, HIF-1a or BMP15. GDF9 mRNA and BAX/BCL-2 were lower and higher at 48 h than at 0 h, respectively. However, the protein expression of BCL-2, CASPASE-3, GDF9 and BMP15 were no different. In the cultured cortex, ROS, TAC and glucose uptake were no different across the three groups.

CONCLUSION

Ovarian tissue transportation was validated for 24 h in the procedure used in clinical practice. This study showed that 4-8°C transportation for 24 or 48 h does not seem to damage the ovarian tissue. However, ovarian tissue transportation beyond 48 h needs to be further studied for conclusions to be made.

Fertility preservation for female patients with childhood, adolescent, and young adult cancer: recommendations from the PanCareLIFE Consortium and the International Late Effects of Childhood Cancer Guideline Harmonization Group

Female patients with childhood, adolescent, and young adult cancer are at increased risk for fertility impairment when treatment adversely affects the function of reproductive organs. Patients and their families desire biological children but substantial variations in clinical practice guidelines reduce consistent and timely implementation of effective interventions for fertility preservation across institutions. As part of the PanCareLIFE Consortium, and in collaboration with the International Late Effects of Childhood Cancer Guideline Harmonization Group, we reviewed the current literature and developed a clinical practice guideline for fertility preservation in female patients who were diagnosed with childhood, adolescent, and young adult cancer at age 25 years or younger, including guidance on risk assessment and available methods for fertility preservation. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to grade the available evidence and to form the recommendations. This clinical practice guideline leverages existing evidence and international expertise to develop transparent recommendations that are easy to use to facilitate the care of female patients with childhood, adolescent, and young adult cancer who are at high risk for fertility impairment. A complete review of the existing evidence, including a quality assessment, transparent reporting of the guideline panel's decisions, and achievement of global interdisciplinary consensus, is an important result of this intensive collaboration.

Can frozen-thawed human ovary withstand refreezing-rethawing in the form of cortical strips?

PURPOSE

The aim of this study was to elucidate whether ovarian tissue is able to withstand a double freezing-thawing procedure.

METHODS

Human ovarian cortical biopsies from 4 thawed whole ovaries were divided into 4 experimental subgroups: (a) frozen-thawed non-grafted group, (b) frozen-thawed xenografted group, (c) refrozen-rethawed non-grafted group, and (d) refrozen-rethawed xenografted group. Xenografting was performed using 8 severe combined immunodeficient mice for a total duration of 21 days. The following analyses were conducted: classic hematoxylin and eosin staining, Ki67 immunolabeling, transmission electron microscopy, Masson's green trichrome, and double CD34 immunostaining.

RESULTS

Morphologically normal preantral follicles were detected in all groups. We observed a dramatic decline of more than 65% in early preantral follicle survival rates after grafting of both frozen-thawed (p < 0.0001) and refrozen-rethawed (p < 0.0001) ovarian tissue. However, mean follicle densities remained comparable between the frozen-thawed and refrozen-rethawed non-grafted groups, as well as both grafted groups. Equivalent proportions of proliferating early preantral follicles were identified in frozen-thawed and refrozen-rethawed samples, whether the tissue was grafted or not. Furthermore, we did not observe any significant difference in atretic follicle rates between any of the four groups, and the ultrastructural quality of follicles appeared unaffected by the refreezing procedure. Similar proportions of fibrosis were noted in the frozen-thawed and refrozen-rethawed groups, irrespective of grafting. Finally, no significant differences were witnessed in terms of vascularization.

CONCLUSION

We were able to demonstrate, for the first time, that refrozen-rethawed ovarian tissue has the same functional characteristics as frozen-thawed ovarian tissue.

Cryopreservation as a Key Element in the Successful Delivery of Cell-Based Therapies-A Review

Cryopreservation is a key enabling technology in regenerative medicine that provides stable and secure extended cell storage for primary tissue isolates and constructs and prepared cell preparations. The essential detail of the process as it can be applied to cell-based therapies is set out in this review, covering tissue and cell isolation, cryoprotection, cooling and freezing, frozen storage and transport, thawing, and recovery. The aim is to provide clinical scientists with an overview of the benefits and difficulties associated with cryopreservation to assist them with problem resolution in their routine work, or to enable them to consider future involvement in cryopreservative procedures. It is also intended to facilitate networking between clinicians and cryo-researchers to review difficulties and problems to advance protocol optimization and innovative design.

Adipose tissue-derived stem cells protect the primordial follicle pool from both direct follicle death and abnormal activation after ovarian tissue transplantation

PURPOSE

To investigate whether adipose tissue-derived stem cells (ASCs) protect the primordial follicle pool, not only by decreasing direct follicle loss but also by modulating follicle activation pathways.

METHODS

Twenty nude mice were grafted with frozen-thawed human ovarian tissue from 5 patients. Ten mice underwent standard ovarian tissue transplantation (OT group), while the remaining ten were transplanted with ASCs and ovarian tissue (2-step/ASCs+OT group). Ovarian grafts were retrieved on days 3 (n = 5) and 10 (n = 5). Analyses included histology (follicle count and classification), immunohistochemistry (c-caspase-3 for apoptosis and LC3B for autophagy), and immunofluorescence (FOXO1 for PI3K/Akt activation and YAP for Hippo pathway disruption). Subcellular localization was determined in primordial follicles on high-resolution images using structured illumination microscopy.

RESULTS

The ASCs+OT group showed significantly higher follicle density than the OT group (p = 0.01). Significantly increased follicle atresia (p < 0.001) and apoptosis (p = 0.001) were observed only in the OT group. In primordial follicles, there was a significant shift in FOXO1 to a cytoplasmic localization in the OT group on days 3 (p = 0.01) and 10 (p = 0.03), indicating follicle activation, while the ASCs+OT group and non-grafted controls maintained nuclear localization, indicating quiescence. Hippo pathway disruption was encountered in primordial follicles irrespective of transplantation, with nuclear YAP localized in their granulosa cells.

CONCLUSION

We demonstrate that ASCs exert positive effects on the ovarian reserve, not only by protecting primordial follicles from direct death but also by maintaining their quiescence through modulation of the PI3K/Akt pathway.

Recent advances in understanding primary ovarian insufficiency

Primary ovarian insufficiency (POI) is an uncommon yet devastating occurrence that results from a premature depletion of the ovarian pool of primordial follicles. Our understanding of both putative and plausible mechanisms underlying POI, previously considered to be largely "idiopathic", has been furthered over the past several years, largely due to advances in the field of genetics and through expansion of translational models for experimental research. In this review, our goal is to familiarize the multidisciplinary readers of the F1000 platform with the strides made in the field of reproductive medicine that hold both preventative and therapeutic implications for those women who are at risk for or who have POI.

Fertility preservation in women for medical and social reasons: Oocytes vs ovarian tissue

Approximately 10% of cancers occur in women under 45 years of age. Chemotherapy, radiotherapy, and bone marrow transplantation cure more than 90% of cancer in women, but can result in premature ovarian insufficiency depending on follicular reserve, age, and drugs used. Some benign diseases are also indications for fertility preservation, particularly those requiring chemotherapy (like thalassemia and lupus), recurrent endometriosis, and family history of premature menopause. Social reasons also account for a large proportion of women who wish to postpone pregnancy. This article discusses the two main strategies for fertility preservation, namely oocyte vitrification and ovarian tissue cryopreservation, examining the indications and results of these options. Oocyte cryopreservation is an effective approach, but further studies are needed in cancer patients to ensure the excellent outcomes obtained in women without cancer or in egg donation programs. For prepubertal girls or cases where immediate therapy is required, cryopreservation of ovarian tissue is the only available option.

Fertility preservation for young adults, adolescents, and children with cancer

Options for fertility preservation (FP) through cryopreservation methods are currently available for young adults, adolescents, and children. Guidelines for FP have been provided by international clinical societies, and emergency procedures aimed at FP have been implemented into clinical practice worldwide. In this article, we review the current data on clinical standards of emergency FP in patients who are facing gonadotoxic effects of cancer treatment, and we also describe the methods that are still under development, usually denoted as experimental. In Sweden, programmes for FP have been established at large university hospitals, thus covering the whole country. The Swedish publicly financed health care covers both assisted reproduction for treatment of infertility and the cryopreservation of gametes or gonadal tissue when there is a medical indication, such as the risk to become infertile due to oncologic treatment; hence the access to FP is ensured for the whole population. At our centre at Karolinska University Hospital in Stockholm, methods for FP have been offered since 1988. In this article, we also review the oncologic indications for FP in our patient cohort of >3000 individuals during the period 1988-2018.

The growth and development conditions in mouse offspring derived from ovarian tissue cryopreservation and orthotopic transplantation

PURPOSE

To investigate the potential development or metabolic risk in offspring derived from mice with transplanted frozen-thawed ovarian tissue.

METHODS

Mice ovaries were intervened by vitrification (group V) and slow-freezing (group S) cryopreservation and orthotopic transplantation. Orthotopic transplantation of fresh ovarian (group F) and natural mating (group C) served as control groups. The fertility restoration and health conditions of generations were assessed by offspring counts, anti-fatigue and motor ability, and organ morphology. The methylation rate and expression level of imprinted genes (IGF2R, H19, SNRPN, and PLAGL1) were used to predict the potential risk of development in transplanted generations.

RESULTS

Both the percentage of normal morphological follicles in different developmental periods and the litter size of receipt mice were comparable in all three transplanted groups. There was no significant difference in offspring mice's birth defects, body weight gain, anti-fatigue ability, or exercise capacity among the four groups. The methylation rate of IGF2R, H19, and PLAGL1 showed a significant variation in cryopreservation groups as compared with control groups, as well as a difference in gene expression. The SNRPN appeared to be stable in methylation status. There were no differences in mRNA expression in all groups.

CONCLUSIONS

The different ovarian tissue cryopreservation methods did not influence either maternal fertility function or offspring growth. However, these technologies could affect the methylation rate and expression level of some development-related imprinting genes in the offspring, which may lead to some indeterminacy risk.

Techniques of Cryopreservation for Ovarian Tissue and Whole Ovary

Cryopreservation of ovarian tissue has been considered experimental for many years, but very recently the American Society of Reproductive Medicine is reviewing the process and perhaps soon will remove the label of “experimental” and recognize it as an established method for preserving female fertility when gonadotoxic treatments cannot be delayed or in patients before puberty or when there is desire to cryopreserve more than just few oocytes. This article discusses in detail the 3 methodologies used for cryopreservation: (a) slow freezing, (b) directional freezing, and (c) vitrification.

Ovarian tissue cryopreservation: Low usage rates and high live-birth rate after transplantation

Introduction

The likelihood of survival after cancer treatment among young women with cancer has increased considerably, quality of life after treatment has drawn more attention. However, in young fertile women, fertility preservation is an important issue with regard to quality of life. One of the options of fertility preservation is ovarian tissue cryopreservation. The purpose of this follow‐up study is to present our clinical experiences and evaluate the long‐term follow up of ovarian cryopreservation to improve future patient selection.

Material and methods

From July 2002 to December 2015 at the Leiden University Hospital, the Netherlands, 69 young women underwent ovarian tissue cryopreservation when they were at risk of iatrogenic premature ovarian insufficiency. Follow‐up data with regard to ovarian function were obtained until October 2018, from medical records and questionnaires.

Results

Of the 69 women in whom ovarian tissue cryopreservation was performed, 12 died (15.9%), 57 were approached to participate, of which 6 were lost to follow up. The indications for ovarian tissue cryopreservation were malignant (81.1%) and benign (18.9%) diseases in which gonadotoxic treatment was scheduled. In total, twenty women (39.2%) are known to have premature ovarian insufficiency due to gonadotoxic treatment. Fifteen women conceived spontaneously, and delivered 25 babies. In this cohort, the usage rate of autotransplantation is 8.7% (7/69). In total, nine autotransplantations of cryopreserved ovarian tissue were performed in seven patients (of which 1 ovarian tissue cryopreservation was performed in another hospital) after which 6 babies were born to four women, giving a live‐birth rate of 57%.

Conclusions

Ovarian tissue cryopreservation followed by autotransplantation is an effective method to restore fertility (live‐birth rate of 57%). The usage rate of 8.7% (6/69) indicates that more knowledge about the risk of premature ovarian insufficiency after gonadotoxic treatment is needed to be able to offer ovarian tissue cryopreservation more selectively.

Ovarian Tissue Transplantation: Experience From Germany and Worldwide Efficacy

Extraction of ovarian tissue prior to oncologic therapy and subsequent transplantation is being performed increasingly often to preserve fertility in women. The procedure can be performed at any time of the cycle and, therefore, generally does not lead to any delay in oncological therapy. Success rates with transplantation of cryopreserved ovarian tissue have reached promising levels. More than 130 live births have been reported worldwide with the aid of cryopreserved ovarian tissue and the estimated birth rate is currently approximately 30%. In Germany, Austria, and Switzerland, the FertiPROTEKT consortium has successfully achieved 21 pregnancies and 17 deliveries generated after 95 ovarian tissue transplantations by 2015, one of the largest case series worldwide confirming that ovarian tissue cryopreservation and transplantation are successful. Approximately, more than 400 ovarian tissue cryopreservation procedures are performed each year in the FertiPROTEKT consortium, and the request and operations for ovarian tissue transplantation have increased in recent years. Therefore, recommendations for managing transplantation of ovarian tissue to German-speaking reproductive medicine centers were developed. In this overview, these recommendations and our experience in ovarian tissue transplantation are presented and discussed with international procedures.

A prospective study of women and girls undergoing fertility preservation due to oncologic and non-oncologic indications in Sweden-Trends in patients' choices and benefit of the chosen methods after long-term follow up

INTRODUCTION

In Scandinavian countries, programs for fertility preservation are offered free of charge at tertiary-care university hospitals to all patients facing treatments with risk of subsequent sterility. In this prospective study we aimed to investigate trends in female patients' choices after counseling and fertility preservation outcomes during follow up in relation to benign vs malignant indications.

MATERIAL AND METHODS

Data on 1254 females including 1076 adults and 178 girls who received fertility preservation counseling for either oncologic (n = 852) or benign indications (n = 402) at Karolinska University Hospital, Stockholm, between 1 October 1998 and 1 December 2018 were analyzed. As appropriate, t tests and chi-square tests were used to compare groups. Logistic regression was used to compare outcomes among groups depending on indications.

RESULTS

Adult women generally elected to undergo oocyte retrieval after controlled ovarian stimulation for cryopreservation of embryos or oocytes (n = 538, 73%), whereas a minor proportion opted for cryopreservation of ovarian tissue retrieved through laparoscopy (n = 221, 27%). More than half of the women with a partner chose either not to fertilize their oocytes aiming at cryopreservation of oocytes or to share obtained oocytes attempting both cryopreservation of oocytes and cryopreservation of embryos. All pre-pubertal (n = 48) and 73% of post-pubertal girls (n = 66) elected cryopreservation of ovarian tissue. In recent years, an increasing number of teenagers have opted for controlled ovarian stimulation aiming at cryopreservation of oocytes, either before (n = 24, 17%) or after completion of cancer treatment (n = 15, 10%). During follow up, 27% of the women returned for a new reproductive counseling, additional fertility preservation or to attempt pregnancy. Utilization rates among individuals who were alive and of childbearing age by December 2018 indicated 29%, 8% and 5% for embryos, oocytes and ovarian tissue with live birth rates of 54%, 46% and 7%, respectively. Women with benign indications were significantly younger than women with previous malignant indications at the time of attempting pregnancy. Although the pregnancy rates were similar among both groups, the live birth rate was significantly higher in women with benign vs previous malignant indications (47% vs 21%, P = .002).

CONCLUSIONS

Trends in fertility preservation choices have changed over time. Women with previous malignancy had lower live birth rates than women with benign fertility preservation indications.

Use of X-Ray Computed Tomography for Ice Detection Applied to Organ Cryopreservation

One of the main problems in the cryopreservation of biological samples is the formation of ice and the consequent mechanical damage to cells and tissues, due to the crystalline structure of ice and its associated mechanical damage. It is necessary to detect this deleterious formation of ice, especially in tissues and organs, because of their large volume and the complexity of their vascular system in the case of bulky organs. In this work, we propose the use of X-ray Computed Tomography (CT) to detect this ice formation inside tissues and organs. To achieve this aim, rabbit kidneys were loaded with cryoprotectant solutions containing Me₂SO at low temperatures (below -140°C). Drops of water with a volume between 2 and 8 μL were then introduced inside the organs. Finally, the rabbit kidneys were cooled to -196°C. Volumes of ice of up to 1 μL were detected in our CT device, with a resolution of up to 50 μm, validating the proposed technology. On the contrary, we analyzed bovine ovarian tissues cryopreserved with a controlled-rate slow-cooling protocol. CT images showed the different structure on the extracellular ice formation according to the procedure, and even the intracellular ice that can be formed in the tissues. These positive results have a straightforward application in the control of the formation of ice, of significant importance for the creation of biobanks.

An Ethical and Legal Analysis of Ovascience - A Publicly Traded Fertility Company and its Lead Product AUGMENT

In May 2015, the first baby created through an emerging ova technology called AUGMENT, was born in Canada.1 Developed by OvaScience, AUGMENT essentially introduces mitochondria sourced from the genetic mother into her own ovum in order to revitalize the ovum.2 This technology is controversial because OvaScience is a publicly traded company, and it is driven by short-term results, such as earnings;3 and (2) OvaScience did not complete adequate clinical trials before offering AUGMENT to the public.4 Moreover, in its 2014 annual report, OvaScience declared that it was intentionally offering its products in countries where clinical trials are not required.5 The lack of adequate clinical trials is the primary reason underlying the Food and Drug Administration's (“FDA”) prohibition of the technology in the United States.6 Finally, as of August 2018, OvaScience has shifted its research away from AUGMENT, and it only offers it through an “exclusive license to IVF Japan Group in Japan.”7

Concept Paper on the Technique of Cryopreservation, Removal and Transplantation of Ovarian Tissue for Fertility Preservation

The cryopreservation of ovarian tissue with subsequent transplantation of the tissue represents an established method of fertility protection for female patients who have to undergo gonadotoxic therapy. The procedure can be performed at any point in the cycle and thus generally does not lead to any delay in oncological therapy. With the aid of this procedure, more than 130 births to date worldwide have been able to be recorded. The birth rate is currently approximately 30% and it can be assumed that this will increase through the further optimisation of the cryopreservation and surgical technique. The concept paper presented here is intended to provide guidance for managing cryopreservation and transplantation of ovarian tissue to German-speaking reproductive medicine centres.

An optimized controlled rate slow cooling protocol for bovine ovarian tissue cryopreservation by means of X-ray computed tomography

Cryopreservation and subsequent transplantation of ovarian tissue is the only option to preserve fertility in certain patients facing gonadotoxic treatment. So far, cryopreservation of ovarian tissue has been carried out mostly by a controlled rate slow cooling process, typically known as slow freezing. Even though there are still some concerns about the iatrogenic damage on the follicle population, this technique has been used in the more than 100 live births reported to date. It is well known that the control of the cryoprotectant loading in the tissue is crucial to in a cryopreservation procedure. We have used the technology of X-ray computed tomography to assess the concentration and distribution of dimethyl sulfoxide (one of the cryoprotectants most used in fertility preservation) inside pieces of bovine ovarian tissue after its cryopreservation. The low voltage used in our device (75 kV) and the high electronic density of this cryoprotectant makes the X-ray attenuation proportional to its concentration. By assessing and comparing the permeation and homogeneity of the cryoprotectant inside ovarian tissue fragments subjected to a controlled rate slow cooling process, we have characterized the effect of variations in the main parameters involved in the process, with the goal of achieving an optimized protocol with higher permeation of the cryoprotectant in the tissue. The most promissory results were obtained by increasing the initial concentration of dimethyl sulfoxide in the vehicle solution from 10 to 20%v/v.

Update on fertility preservation from the Barcelona International Society for Fertility Preservation-ESHRE-ASRM 2015 expert meeting: indications, results and future perspectives

STUDY QUESTION

What progress has been made in fertility preservation (FP) over the last decade?

SUMMARY ANSWER

FP techniques have been widely adopted over the last decade and therefore the establishment of international registries on their short- and long-term outcomes is strongly recommended.

WHAT IS KNOWN ALREADY

FP is a fundamental issue for both males and females whose future fertility may be compromised. Reproductive capacity may be seriously affected by age, different medical conditions and also by treatments, especially those with gonadal toxicity. There is general consensus on the need to provide counselling about currently available FP options to all individuals wishing to preserve their fertility.

STUDY DESIGN, SIZE, DURATION

An international meeting with representatives from expert scientific societies involved in FP was held in Barcelona, Spain, in June 2015.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Twenty international FP experts belonging to the American Society of Reproductive Medicine, ESHRE and the International Society of Fertility Preservation reviewed the literature up to June 2015 to be discussed at the meeting, and approved the final manuscript. At the time this manuscript was being written, new evidence considered relevant for the debated topics was published, and was consequently included.

MAIN RESULTS AND THE ROLE OF CHANCE

Several oncological and non-oncological diseases may affect current or future fertility, either caused by the disease itself or the gonadotoxic treatment, and need an adequate FP approach. Women wishing to postpone maternity and transgender individuals before starting hormone therapy or undergoing surgery to remove/alter their reproductive organs should also be counselled accordingly. Embryo and oocyte cryopreservation are first-line FP methods in post-pubertal women. Metaphase II oocyte cryopreservation (vitrification) is the preferred option. Cumulative evidence of restoration of ovarian function and spontaneous pregnancies after ART following orthotopic transplantation of cryopreserved ovarian tissue supports its future consideration as an open clinical application. Semen cryopreservation is the only established method for FP in men. Testicular tissue cryopreservation should be recommended in pre-pubertal boys even though fertility restoration strategies by autotransplantation of cryopreserved testicular tissue have not yet been tested for safe clinical use in humans. The establishment of international registries on the short- and long-term outcomes of FP techniques is strongly recommended.

LIMITATIONS, REASONS FOR CAUTION

Given the lack of studies in large cohorts or with a randomized design, the level of evidence for most of the evidence reviewed was three or below.

WIDER IMPLICATIONS OF THE FINDINGS

Further high quality studies are needed to study the long-term outcomes of FP techniques.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

Isolation and in vitro culture of ovarian stem cells in Chinese soft-shell turtle (Pelodiscus sinensis)

Gonadal cell lines provide valuable tools for studying gametogenesis, sex differentiation, and manipulating germ cells in reproductive biology. Female germline stem cells have been characterized and isolated from ovaries of mammalian species, including mice and human, but there has been very few studies on female germline stem cells in reptiles. Here, we described an ovarian stem cell-like line isolated and cultured from the Chinese soft-shell turtle (Pelodiscus sinensis), designated as PSO1. The cells showed high alkaline phosphatase activity with a normal diploid karyotype. As shown by reverse transcription-polymerase chain reaction, the cells were positive for the expression of germ cell-specific genes, vasa and dazl, as well as a stem cell marker, nanog, but negative for the expression of the folliculogenesis-specific gene, figla. Likewise, through fluorescent immunostaining analyses, both the Dazl and Vasa proteins were detected abundantly in the cytoplasm of perinuclear region, whereas Nanog and PCNA were dominantly observed in the nuclei in PSO1 cells. Moreover, PSO1 cells transfected with pCS2:h2b-egfp could properly express the fusion protein in the nuclei. Taken together, the findings suggested that the germline stem cells exist in the ovary of juvenile Chinese soft-shell turtle and these cells can be isolated for a long-term in vitro culture under experimental conditions. This study has provided a valuable basis for further investigations on the molecular mechanisms whereby the germline stem cells develop and differentiate into gametes in turtles. Also, it has paved the way for studies on oogenesis in turtles, even in the other reptiles.

Comparison of the enzymatic efficiency of Liberase TM and tumor dissociation enzyme: effect on the viability of cells digested from fresh and cryopreserved human ovarian cortex

BACKGROUND

The aim of this study was to examine the effectiveness of Tumor Dissociation Enzyme (TDE) on the viability of follicles after digestion of fresh and cryopreserved ovarian cortex fragments (OCFs).

METHODS

Fresh and thawed OCF from 14 patients (29 ± 6 years), sized 20 to 210 mm³ were randomly distributed into four treatment groups and digested with 16% TDE or 0.05 mg/ml Liberase TM: Group 1, frozen OCF digested with TDE; Group 2, frozen OCF digested with LiberaseTM; Group 3, fresh OCF digested with TDE; and Group 4, fresh OCF digested with Liberase TM. Evaluation of follicle viability was performed under light microscope after staining with Neutral red. For visualization of viable and dead cells under a confocal laser scanning microscope, the follicles were stained with Calcein AM and ethidium homodimer-1.

RESULTS

The results showed that the number of retrieved follicles was significantly higher (990 vs 487; P < 0.01) in the TDE-treatment group compared to the Liberase TM-group. The presence of intense neutral red stained follicles was significantly higher in Group 1 and Group 3 compared to Group 2 and Group 4 (70.3% ± +/- 6.22 vs 53,1% ± 2.03 and 94.2% ± 6.6 vs 79.1% ± 2.1; P < 0.01). The percentage of Calcein AM stained follicles of class V1 was significantly higher in Group 1 and Group 3 compared to Group 2 and Group 4 (95.97% ± 7.8 vs 87.87% ± 2.4; 97.1% ± 6.8 vs 91.3% ± 2.3; P < 0.01).

CONCLUSION

The enzymatic digestion of ovarian cortex with TDE provides recovery of a higher number of healthy preantral follicles in contrast to earlier described Liberase TM procedure.

Fertility preservation healthcare circuit and networks in cancer patients worldwide: what are the issues?

Background

Fertility preservation (FP) is a major determinant of quality of life after cancer remission for women who may not have achieved their ideal family size. This article describes the FP services and strategy currently available, highlighting issues of oncofertility worldwide.

Main body of the abstract

For these patients in complex situations, health networks are essential to improve coordination of care, and the strengthening of this coordination is a major challenge to improve the performance of the health system. Two international networks have been created in order to foster scientific exchange between countries and to standardize the oncofertility healthcare circuit. However, the paucity of referral nationwide networks lead to a structural gap in health care policies.

Short conclusion

Management strategies of oncofertility in the world are still fragile and uneven. To structure the oncofertility sector, a multidisciplinary project allowing teams to collaborate is of utmost importance particularly in low and middle-income countries.

Fertility protection: complications of surgery and results of removal and transplantation of ovarian tissue

Fertility-preserving measures are becoming important for patients receiving oncological treatment. One method involves cryopreservation of ovarian tissue and transplanting it when treatment is completed. We report complications resulting from surgical and fertility medicine, and the results of procedures for the removal and transplantation of ovarian tissue carried out within the FertiProtekt network. A survey using a structured questionnaire was conducted among the FertiProtekt network centres between November 2015 and June 2016. The analysis included surgical techniques used to remove and transplant ovarian tissue, surgical complications and results. Laparoscopic removal and transplantation of ovarian tissue have a low risk of complications. Surgical complications occurred in three of the network's 1373 ovarian tissue removals (n = 1302) and transplantations (n = 71); two complications (0.2%) occurred during removal and one during transplantation. Menstruation resumed in 47 out of 58 women (81%) who underwent ovarian tissue transplantation. Hormonal activity occurred in 63.2% of transplantations with a follow-up of 6 months or over. Sixteen pregnancies occurred in 14 patients, with nine births. The risks and complications of removal and transplantation of ovarian tissue are similar to those of standard laparoscopy. These procedures are becoming standard for fertility protection in cancer patients.

Fertility preservation in post-pubescent female cancer patients: A practical guideline for clinicians

Increasing accessibility of fertility preservation (FP) options has permitted women to retain fertility following anticancer therapies. Several published guidelines have made recommendations for FP however their implementation into practice is currently unknown. In this review, we aim to provide oncology clinicians practical information about FP options for post-pubescent female cancer patients and recommendations for care delivery in order to answer preliminary questions and help triage whether FP referral is appropriate. Herein, we present a resource for oncology providers to guide them with FP discussions. Key points that are discussed in this critical review include: i) All cancer patients beginning a new plan of care should be informed of potential fertility risk. ii) If a woman requests further information on FP interventions, referral to a FP clinic should be made. iii) Given the evolving technologies in this area, patients should be informed of those which are proven and unproven, with oocyte and embryo preservation recognized as standard practice. iv) Random start (independent of menstrual cycle day) techniques are available to minimize oncologic treatment delays. v) Specific protocols for ovarian stimulation may be center-specific. vi) There is unlikely an increased cancer recurrence risk as a result of stimulation protocols in women with hormone-sensitive cancers. vii) Lastly, given the absence of consensus in the literature, routine use of GnRH analogs is not recommended for all cancer patients, however may be considered in select cases, such as high-risk women in whom definitive FP is not possible or feasible.

A transportation network for human ovarian tissue is indispensable to success for fertility preservation

PURPOSE

The purpose of this study was to examine the efficacy of an ovarian tissue transportation network for fertility preservation (FP) for cancer patients in Japan.

METHODS

PubMed was searched for papers on transportation of human ovarian tissue for FP. We analyzed population, area, number of cancer patients for ovarian tissue cryopreservation (OTC), quality control/assessment and safety, cost of a cryopreservation center for the building for 30 years, and medical fees of cancer patients (operation, cryopreservation, and storage of ovarian tissue).

RESULTS

More than twenty babies have been born in Denmark and Germany through a transportation system. Up to 400 new patients a year need OTC. The fees for removal, cryopreservation, and storage for 5 years, and transplantation of ovarian tissue are around €5,000, €4,000, and €5,000, respectively. It costs more than €5 million to establish and maintain one cryopreservation center for 30 years. If we have a few cryopreservation centers in Japan, we can cryopreserve 400 patients' ovarian tissue per year by safer slow freezing and maintain quality control/assessment. We need to lighten the patients' burden for easy to use FP by a government subsidy and medical insurance coverage.

CONCLUSIONS

This model has been termed the Danish model ("the woman stays - the tissue moves"). This is truly patient-centered medicine. We can have maximum effects with the minimum burden. A transportation network like those of Denmark and Germany is the best strategy for FP in Japan. It may be the best system for cancer patients, medical staff, and the Ministry of Health, Labor, and Welfare.

Female fertility preservation in the pediatric and adolescent cancer patient population

The 5-year survival rate for childhood cancer is over 80%, thereby increasing the number of young women facing infertility in the future because of the gonadotoxic effects of chemotherapy and radiation. The gonadotoxic effects of childhood cancer treatment vary by the radiation regimen and the chemotherapeutic drugs utilized. Although the American Society of Clinical Oncology guidelines recommend fertility preservation for all patients, there are several barriers and ethical considerations to fertility preservation in the pediatric and adolescent female population. Additionally, the fertility preservation methods for pre- and postpubertal females differ, with only experimental methods available for prepubertal females. We will review the risk of chemotherapy and radiation on female fertility, the approach to fertility preservation in the pediatric and adolescent female population, methods of fertility preservation for both pre- and postpubertal females, barriers to fertility preservation, cost, and psychological and ethical considerations.

Morphological and phenotypical features of ovarian metastases in breast cancer patients

Background

Autotransplantation of frozen-thawed ovarian tissue is a method to preserve ovarian function and fertility in patients undergoing gonadotoxic therapy. In oncology patients, the safety cannot yet be guaranteed, since current tumor detection methods can only exclude the presence of malignant cells in ovarian fragments that are not transplanted. We determined the need for a novel detection method by studying the distribution of tumor cells in ovaries from patients with breast cancer. Furthermore, we examined which cell-surface proteins are suitable as a target for non-invasive tumor-specific imaging of ovarian metastases from invasive breast cancer.

Methods

Using the nationwide database of the Dutch Pathology Registry (PALGA), we identified a cohort of 46 women with primary invasive breast cancer and ovarian metastases. The localization and morphology of ovarian metastases were determined on hematoxylin-and-eosin-stained sections. The following cell-surface markers were immunohistochemically analyzed: E-cadherin, epithelial membrane antigen (EMA), human epidermal growth receptor type 2 (Her2/neu), carcinoembryonic antigen (CEA), αvβ6 integrin and epithelial cell adhesion molecule (EpCAM).

Results

The majority of ovarian metastases (71%) consisted of a solitary metastasis or multiple distinct nodules separated by uninvolved ovarian tissue, suggesting that ovarian metastases might be overlooked by the current detection approach. Combining the targets E-cadherin, EMA and Her2/neu resulted in nearly 100% detection of ductal ovarian metastases, whereas the combination of EMA, Her2/neu and EpCAM was most suitable to detect lobular ovarian metastases.

Conclusions

Examination of the actual ovarian transplants is recommended. A combination of targets is most appropriate to detect ovarian metastases by tumor-specific imaging.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3191-y) contains supplementary material, which is available to authorized users.