Is Ovarian Tissue Cryopreservation and Transplantation Still Experimental? It Is a Matter of Female Age and Type of Cancer

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.

Safety and efficacy of ovarian tissue autotransplantation: A systematic literature review

Ovarian tissue autotransplantation is an innovative fertility preservation technique that has provoked ongoing investigations. The purpose of the present study was to assess the safety and reproductive performance of ovarian tissue autotransplantation. This review is conducted according to PRISMA guidelines. Seven studies met the inclusion criteria. A total of 3427 patients underwent ovarian tissue cryopreservation and 205 received an autotransplantation. Tissue retrieval was mainly performed by laparoscopy and only one major complication occurred. Transplantations were predominantly performed by open procedures and data on safety were insufficient. A total of 295 autotransplantations were analyzed, resulting in 104 pregnancies. Sixty-five pregnancies led to live births, while nine were ongoing at that time. A pregnancy rate (PR) of 50.7% and a live-birth rate (LBR) of 32.7% were observed. Natural conception accounted for 46.3% of live births. No birth deficits were recorded. Ovarian tissue autotransplantation seems to be a safe procedure with acceptable pregnancy rates.

In vitro growth (IVG) of human ovarian follicles in frozen thawed ovarian cortex tissue culture supplemented with follicular fluid under hypoxic conditions

Background

Despite its clinical success rates, transplantation after ovarian tissue cryopreservation (OTC) remains a matter of concern. Certain cancer subtypes may lead to the transfer of malignant cells when transplantation of affected ovarian tissue is conducted. IVG and subsequent isolation of vital follicles obtained from frozen thawed ovarian tissue for further in vitro maturation (IVM) would expand current fertility protection techniques while reducing the risk of retransplanting malignant cells.

Methods

A total of 216 cortical biopsies from 3 patients were included in this study in 4 treatment groups. After freezing, thawing and 8 days of hypoxic tissue culture supplemented with different concentrations of human follicular fluid (HuFF) and follicle-stimulating hormone (FSH), follicles were isolated enzymatically and stained with calcein to determine follicular viability. Numbers and size of vital follicles were assessed by fluorescence microscopy (Ti2, Nikon) and specified by computer assisted, semi-automated measurement (NIS software, Nikon). To estimate the effect of in vitro culture on apoptosis, tissue sections were stained for nicked DNA (TUNEL) prior and after tissue culture.

Results

Analysing 3025 vital follicles, we observed significant differences [P < 0.01] regarding follicle size when hypoxic tissue culture was supplemented with HuFF compared with the control group on day 1, individual follicles reached sizes > 100 µm.

Conclusions

The results implicate that HuFF contains valuable factors contributing to significant IVG of follicles in human ovarian tissue and could be regarded as an additional tool in personalized fertility restoration prior to retransplantation of ovarian tissue.

How much total ovarian tissue can be removed without compromising ovarian function? An animal study

OBJECTIVE

Removal of ovarian tissue is a new option for fertility preservation for certain cancer patients in China. The aim was to investigate the impact of stepwise removed tissue on hormone levels and follicles in rats.

METHODS

Six to ten-week old rats were divided into six groups (% total ovarian tissue): 1 = control (100%), 2 (75%), 3 (50%), 4 (25%), 5 (12.5%), 6 (0%, bilateral ovariectomy). Blood test was carried out fortnightly to assess estradiol (E2), progesterone (P), follicle-stimulating hormone (FSH), anti-Müllerian hormone (AMH), and inhibin B (INHB). Ovaries are obtained from surgical resections and from rats sacrificed after 12 weeks.

RESULTS

During 12 weeks, groups 4, 5, and 6 had higher FSH and lower AMH and INHB values compared to control (p< .05), but in group 4 E2 and P was not significantly different from control (p> .05). All ovarian function parameters stopped in groups 5 and 6. Follicle morphology was not significantly different between baseline and 12 weeks after surgery in groups 1-5.

CONCLUSIONS

For the first time, we demonstrated that even up to 75% of total ovarian tissue can be removed without impact on E2 and P production in rats, which, if confirmed in women, would mean that hazardous (or possibly contraindicated in cancer patients) hormone therapy is not required to avoid the negative consequences of hormone depletion.

Preservation of connexin 43 and transzonal projections in isolated bovine pre-antral follicles before and following vitrification

PURPOSE

Gap junctions and transzonal projections play a crucial role in intercellular communication between different follicular components and are necessary for follicle development. We aimed to demonstrate gap junction protein connexin 43 (Cx43) and transzonal projections (TZPs) in viable, category 1, isolated bovine pre-antral follicles (PAFs) during short-term culture and after vitrification and warming.

METHODS

This study involved four experimental groups: fresh control, 2-day culture, 4-day culture, and vitrified secondary PAFs. Isolated PAFs were vitrified using a simple and efficient cryopreservation method by means of mini cell strainers.

RESULTS

Cx43 and TZPs were detected in pre-antral follicles of all stages, as well as in every experimental group. The group fresh follicles showed a higher percentage of follicles that were positive for Cx43 (91.7%) than the follicles that were vitrified (77.4%). All follicles that were cultured for 2 days were Cx43-positive (100%). Follicles cultured for 4 days (65.8%) (P = 0.002) showed the lowest percentage of follicles that were Cx43-positive. The percentages of the presence or (partial) absence of the TZP network were shown to be very heterogeneous between follicles in different treatment groups.

CONCLUSIONS

These results suggest the maintenance of communication between the oocyte and the somatic companion cells after vitrification and warming. The varying percentages of the expression of the TZP network within groups suggests that it will be of interest to investigate whether this is truly due to variability in TZP integrity and follicle quality or due to methodological limitations.

Human Ovarian Cortex biobanking: A Fascinating Resource for Fertility Preservation in Cancer

Novel anti-cancer treatments have improved the survival rates of female young patients, reopening pregnancy issues for female cancer survivors affected by the tumor treatment-related infertility. This condition occurs in approximately one third of women of fertile age and is mainly dependent on gonadotoxic protocols, including radiation treatments. Besides routine procedures such as the hormonal induction of follicular growth and subsequent cryopreservation of oocytes or embryos, the ovarian protection by gonadotropin-releasing hormone (GnRH) agonists during chemotherapy as well as even gonadal shielding during radiotherapy, other innovative techniques are available today and need to be optimized to support their introduction into the clinical practice. These novel methods are hormone stimulation-free and include the ovarian cortex cryopreservation before anti-cancer treatments and its subsequent autologous reimplantation and a regenerative medicine approach using oocytes derived in vitro from ovarian stem cells (OSCs). For both procedures, the major benefit is related to the prompt recruitment and processing of the ovarian cortex fragments before gonadotoxic treatments. However, while the functional competence of oocytes within the cryopreserved cortex is not assessable, the in vitro maturation of OSCs to oocytes, allows to select the most competent eggs to be cryopreserved for fertility restoration.

FertiPROTEKT, Oncofertility Consortium and the Danish Fertility-Preservation Networks - What Can We Learn From Their Experiences?

Fertility preservation is an increasingly important discipline. It requires close coordination between reproductive medicine specialists, reproductive biologists, and oncologists in various disciplines. In addition, it represents a particular health policy challenge, since fertility-protection measures are to be understood as a treatment for side effects of gonadotoxic treatments and would therefore normally have to be reimbursed by health insurance companies. Therefore, it is inevitable that fertility-preservation activities should organise themselves into a network structure both as a medical-logistic network and as a professional medical society. The necessary network structures can differ significantly at regional, national, and international level, as the size of the regions to be integrated and the local cultural and geographical conditions, as well as the political conditions are very different. To address these issues, the current review aims to point out the basic importance and the chances but also the difficulties of fertility-protection networks and give practical guidance for the development of such network structures. We will not only discuss network structures theoretically but also present them based on three established, different sized networks, such as the Danish Network (www.rigshospitalet.dk), representing a centralised network in a small country; the German-Austrian-Swiss network FertiPROTEKT® (www.fertiprotekt.com), representing a centralised as well as decentralised network in a large country; and the Oncofertility® Consortium (www.oncofertility.northwestern.edu), representing a decentralised, internationally oriented network, primarily serving the transfer of knowledge among its members.

Fertility preservation in female cancer patients: current knowledge and future perspectives

INTRODUCTION

Protecting fertility in the presence of cancer has become highly significant, as the desire to give birth to a child is increasingly postponed to later in life, and long-term survival with cancer has increased. A variety of fertility-preserving methods have been developed.

EVIDENCE ACQUISITION

To find them, we performed a literature search in Medline using the key words "female fertility preservation in cancer" in December 2017. A total of 2381 different publications were found.

EVIDENCE SYNTHESIS

After screening the abstracts 78 publications in English, French, or German language had been assessed as relevant (17 dealing with medical approaches, six with surgical approaches, 15 with oocyte cryopreservation, 11 with ovarian tissue cryopreservation and 29 were review articles). In general, there are medical (non-surgical) and surgical approaches. Medical approaches comprise administration of GnRH-analogues during gonad toxic oncologic treatment, and cryopreservation of oocytes after ovarian stimulation. Surgical approaches comprise traditional methods of organ-saving surgery and ovarian transposition outside of the radiation portal as well as ovary cryopreservation as standard.

CONCLUSIONS

It is important to inquire about a prospective desire to have children with premenopausal women with cancer and comprehensively explain the fertility conserving methods available. Every premenopausal woman with cancer should be counseled about the methods of fertility protection currently available at a multiprofessional center.

Successful conception in a 34-year-old lupus patient following spontaneous pregnancy after autotransplantation of cryopreserved ovarian tissue

Premature gonadal failure is a common problem in patients with systemic lupus erythematosus (SLE) when gonadotoxic therapies are applied. The preservation of gonadal function and fertility is of great importance to many predominantly young SLE patients. Some fertility preservation methods are well established and well known, whereas others are considered more cautiously. In particular, the cryopreservation of ovarian tissue is a rarely chosen fertility preservation option for SLE patients of (pre)fertile age. We report the first case of successful conception and pregnancy of an SLE patient after autotransplantation of cryopreserved ovarian tissue. A 26-year-old SLE patient decided to undergo cryopreservation of ovarian tissue when receiving cyclophosphamide for lupus nephritis. Tissue removal, preparation, cryopreservation and quality control was performed, as described, according to current state-of-the-art techniques. After 6 years of being in remission using azathioprine and belimumab, her ovarian tissue was autotransplanted because of premature ovarian failure, diagnosed at the age of 32, and a wish to conceive. She conceived spontaneously 8 months later, having a diamniotic-dichoriotic twin pregnancy. The children were born prematurely due to preterm premature rupture of membranes in the 32nd week of gestation; mother and children are doing very well 8 months later. We regard the procedure to be an option worth consideration for our predominantly young SLE patients.

Overnight ovarian tissue transportation for centralized cryobanking: a feasible option

RESEARCH QUESTION

Is overnight transportation of ovarian tissue before cryopreservation in a centralized cryobank from the FertiPROTEKT network feasible?

DESIGN

Data from 1810 women with cryopreserved ovarian tissue after overnight transportation from December 2000 to December 2017 were analysed with a focus on transportation, tissue activity parameters and pregnancy, and delivery rates after transplantation.

RESULTS

A total of 92.4% of tissue samples arrived at ideal temperatures of 2-8°C, 0.4% were transported at temperatures lower than ideal and 6.4% were transported at temperatures that were too high, generally due to mishandling of the inlayed cool packs of the transportation boxes. In 62 women, 78 tissue transplantations were carried out. A subgroup of 30 women who underwent a single orthotopic transplantation with fulfilled criteria of a complete follow-up after transplantation until the end of study, a premature ovarian insufficiency after gonadotoxic therapy as well as the absence of pelvic radiation, was further analysed. In this group, transplantations into a peritoneal pocket accounted for 90%. Transplants were still active at 1 year and above after transplantation in 93.3%. Pregnancy and delivery rates were 46.7% and 43.3%, respectively, with one ongoing pregnancy at the end of the study.

CONCLUSIONS

Overnight transportation for central cryobanking is a feasible concept that results in high reproducible success rates through standardized professional tissue freezing and storage.

Fertility Preservation for Child and Adolescent Cancer Patients in Asian Countries

Background: At present, fertility is one of the main concerns of young cancer patients. Following this trend, "fertility preservation (FP)" has been established and has become a new field of reproductive medicine. However, FP for child and adolescent (C-A) cancer patients is still developing, even in advanced countries. The aim of the present study was to assess the barriers to FP for C-A patients by investigating the current status of FP for C-A patients in Asian countries, which just have started FP activities. Method: A questionnaire survey of founding members of the Asian Society for Fertility Preservation (ASFP) was conducted in November 2018. Main findings: Of the 14 countries, 11 country representatives replied to this survey. FP for C-A patients is still developing in Asian countries, even in Australia, Japan, and Korea, which have organizations or academic societies specialized for FP. In all countries that replied to the present survey, the patients can receive embryo cryopreservation (EC), oocyte cryopreservation (OC), and sperm cryopreservation (SC) as FP. Compared with ovarian tissue cryopreservation (OTC), testicular tissue cryopreservation (TTC) is an uncommon FP treatment because of its still extremely experimental status (7 of 11 countries provide it). Most Asian countries can provide FP for C-A patients in terms of medical technology, but most have factors inhibiting to promote FP for C-A patients, due to lack of sufficient experience and an established system promoting FP for C-A patients. "Don't know how to provide FP treatment for C-A" is a major barrier. Also, low recognition in society and among medical staff is still a particularly major issue. There is also a problem with cooperative frameworks with pediatric departments. To achieve high-quality FP for C-A patients, a multidisciplinary approach is vital, but, according to the present study, few paramedical staff can participate in FP for C-A patients in Asia. Only Australia and Korea provide FP information by video and specific resources. Conclusion: The present study demonstrated the developing status of FP for C-A patients in Asian countries. More intensive consideration and discussion are needed to provide FP in Asian societies based on the local cultural and religious needs of patients.