Testicular tissue cryopreservation in prepubertal male children: an analysis of parental decision-making

Testis tissue cryopreservation may be considered in boys with cryptorchidism

ABSTRACT

This study assessed the feasibility of testis tissue cryopreservation (TTC) for fertility preservation in prepubescent boys with cryptorchidism. From January 2014 to December 2022, the University Hospital of Copenhagen (Rigshospitalet, Copenhagen, Denmark) implemented TTC for 56 boys with cryptorchidism to preserve their reproductive potential. Testis tissue samples were collected during orchiopexy (32 cases) or at subsequent follow-up procedures (24 cases), necessitated by an increased risk of infertility as indicated by hormonal assessments and/or findings from initial surgical biopsies. Testis samples were procured for TTC and pathological analysis. The cohort had an average age of 1.3 (range: 0.3-3.8) years at the time of orchiopexy, with 91.1% presenting bilateral cryptorchidism. The study revealed a median germ cell count of 0.39 (range: 0-2.88) per seminiferous tubule, with germ cells detected in 98.0% of the bilateral biopsies and 100% of the unilateral, indicating a substantial potential for fertility in these immature tissues. A dark spermatogonia (Ad) was detected in 37 out of 56 patients evaluated, with a median Ad spermatogonia count of 0.027 (range: 0.002-0.158) per seminiferous tubule. A total of 30.2% of the samples lacked Ad spermatogonia, indicative of potential gonadotrophin insufficiency. The median hormone levels measured were as follows: follicle-stimulating hormone (FSH) at 0.69 (range: 0.16-2.5) U l -1 , luteinizing hormone (LH) at 0.21 (range: 0.05-3.86) U l -1 , and inhibin B at 126 (range: 17-300) pg ml -1 . Despite early orchiopexy, 20%-25% of boys with cryptorchidism remain at risk for future infertility, substantiating the necessity of TTC as a precaution. The study highlights the need for refined predictive techniques to identify boys at higher risk of future infertility.

Comprehensive fertility preservation can be offered in a timely manner around gonadotoxic therapy in children and adolescents

BACKGROUND

Treatment for certain childhood cancers and nonmalignant conditions can lead to future infertility and gonadal failure. The risk of treatment delay must be considered when offering fertility preservation (FP) options. We examined the timeline from FP referral to return to treatment (RTT) in pediatric patients who underwent FP due to iatrogenic risk for infertility.

METHODS

A retrospective review was performed of patients with FP consultation due to an increased risk of iatrogenic infertility at Ann & Robert H. Lurie Children's Hospital of Chicago from 2018 to 2022. Data on diagnosis, age, treatment characteristics, and procedure were collected.

RESULTS

A total of 337 patients (n = 149 with ovaries, n = 188 with testes) had an FP consultation. Of patients with ovaries, 106 (71.1%) underwent ovarian tissue cryopreservation (OTC), 10 (6.7%) completed ovarian stimulation/egg retrieval (OSER), and 33 (22.1%) declined FP. Of the patients with testes, 98 (52.1%) underwent testicular tissue cryopreservation (TTC), 48 (25.5%) completed sperm banking (SB), and 42 (22.3%) declined FP. Median time from referral to FP consultation was short (ovaries: 2 days, range: 0-6; testes: 1 day, range: 0-5). OSER had a significantly longer RTT versus OTC and no FP (52.5 vs.19.5 vs. 12 days, p = .01). SB had a significantly quicker RTT compared to TTC or no FP (9.0 vs. 21.0 vs. 13.5 days; p = .008). For patients who underwent OTC/TTC and those who declined FP, there was no significant difference in time from consultation to treatment.

CONCLUSIONS

It is feasible to promptly offer and complete FP with minimal delay to disease-directed treatment.

The effect of red blood cell disorders on male fertility and reproductive health

Male infertility is defined as a failure to conceive after 12 months of unprotected intercourse owing to suspected male reproductive factors. Non-malignant red blood cell disorders are systemic conditions that have been associated with male infertility with varying severity and strength of evidence. Hereditary haemoglobinopathies and bone marrow failure syndromes have been associated with hypothalamic-pituitary-gonadal axis dysfunction, hypogonadism, and abnormal sperm parameters. Bone marrow transplantation is a potential cure for these conditions, but exposes patients to potentially gonadotoxic chemotherapy and/or radiation that could further impair fertility. Iron imbalance might also reduce male fertility. Thus, disorders of hereditary iron overload can cause iron deposition in tissues that might result in hypogonadism and impaired spermatogenesis, whereas severe iron deficiency can propagate anaemias that decrease gonadotropin release and sperm counts. Reproductive urologists should be included in the comprehensive care of patients with red blood cell disorders, especially when gonadotoxic treatments are being considered, to ensure fertility concerns are appropriately evaluated and managed.

A 10-year experience in testicular tissue cryopreservation for boys under 18 years of age: What can be learned from 350 cases?

BACKGROUND

A growing number of centers worldwide are preserving testicular tissue (TT) of young boys at risk of fertility loss to preserve their fertility. Data in this regard are scarce and experience sharing is essential to the optimization of the process.

OBJECTIVES

This report of our 10-year activity of pediatric fertility preservation (FP) has the objective to (1) improve knowledge regarding the feasibility, acceptability, safety, and potential usefulness of the procedure; (2) analyze the impact of chemotherapy on spermatogonia in the cryopreserved TT.

MATERIALS AND METHODS

For this retrospective study of data prospectively recorded, we included all boys under 18 years of age referred to the FP consultation of our academic network between October 2009 and December 2019. Characteristics of patients and cryopreservation of testicular tissue (CTT) were extracted from the clinical database. Univariate and multivariate analyses were used to assess factors associated with the risk of absence of spermatogonia in the TT.

RESULTS

Three hundred and sixty-nine patients (7.2 years; 0.5-17.0) were referred to the FP consultation for malignant (70%) or non-malignant (30%) disease, of whom 88% were candidates for CTT, after a previous chemotherapy exposure (78%). The rate of recorded immediate adverse events was 3.5%, with painful episodes dominating. Spermatogonia were detected in the majority of TTs: 91.1% of those exposed to chemotherapy and 92.3% of those not exposed (p = 0.962). In multivariate analysis, the risk of absence of spermatogonia was almost three-fold higher in boys > 10 years of age ([OR] 2.74, 95% CI 1.09-7.26, p = 0.035) and four-fold higher in boys exposed to alkylating agents prior to CTT ([OR] 4.09, 95% CI 1.32-17.94, p = 0.028).

DISCUSSION/CONCLUSION

This large series of pediatric FP shows that this procedure is well accepted, feasible, and safe in the short term, strengthening its place in the clinical care pathway of young patients requiring a highly gonadotoxic treatment. Our results demonstrate that CTT post-chemotherapy does not impair the chance to preserve spermatogonia in the TT except when the treatment includes alkylating agents. More data on post-CTT follow-up are still required to ensure the long-term safety and usefulness of the procedure.

Fertility Preservation in Children and Adolescents during Oncological Treatment-A Review of Healthcare System Factors and Attitudes of Patients and Their Caregivers

Oncofertility is any therapeutic intervention to safeguard the fertility of cancer patients. Anti-cancer therapies (chemotherapy, radiation therapy, etc.) entail the risk of reproductive disorders through cytotoxic effects on gamete-building cells, especially those not yet fully developed. This literature review analyzes the available data on securing fertility in pediatric and adolescent populations to identify the methods used and describe aspects related to financing, ethics, and the perspective of patients and their parents. Topics related to oncofertility in this age group are relatively niche, with few peer-reviewed articles available and published studies mostly on adults. Compared to pubertal individuals, a limited number of fertility preservation methods are used for prepubertal patients. Funding for the procedures described varies from country to country, but only a few governments choose to reimburse them. Oncofertility of pediatric and adolescent patients raises many controversies related to the decision, parents' beliefs, having a partner, ethics, as well as the knowledge and experience of healthcare professionals. As the fertility of young cancer patients is at risk, healthcare professionals should make every effort to provide them with an opportunity to fulfill their future reproductive plans and to have a family and offspring. Systemic solutions should form the basis for the development of oncofertility in pediatric and adolescent populations.

Gonadal development and function after immature testicular tissue banking as part of high-risk gonadotoxic treatment

BACKGROUND

Experimental fertility preservation programs have been started to safeguard the future fertility of prepubertal and pubertal males requiring high-risk gonadotoxic treatment protocols. However, long-term follow-up studies evaluating the effects on their gonadal development and function related to the testicular biopsy procedure are rather limited.

DESIGN

This two-center follow-up study (between 2002 and 2020) evaluated the gonadal development and function of a cohort of 59 prepubertal and pubertal males who have been offered immature testicular tissue banking (TTB) prior to conventional high-risk chemo- and/or radiotherapy (HR-C/R) or conditioning therapy before hematopoietic stem cell transplantation (CT-HSCT). The aim is to investigate the long-term impact of the testicular biopsy procedure and the high-risk gonadotoxic treatment. Testicular growth and the reproductive hormones luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T), and inhibin B (INHB) were analyzed after treatment completion, and compared between males accepting TTB and those refusing TTB (control) as well as between HR-C/R and CT-HSCT treatment protocols.

RESULTS

Of the 59 prepubertal and pubertal males included, 25 were treated by HR-C/R and 34 required CT-HSCT. TTB was accepted for 39 males and refused for 20 males. Most patients were prepubertal at diagnosis (85%), at TTB (79%), and at treatment completion (76%), and pubertal or postpubertal at their last follow-up visit (66%). After 5.0 (1.0-13.0) years post treatment, most patients show normal testicular volumes (83%) and normal LH (89%), FSH (87%), T (87%), and INHB (79%) serum levels. The testicular biopsy procedure did not have an effect on testicular growth, LH, FSH, T, and INHB. Significantly more small postpubertal testicular volumes (p = .0278) and low INHB serum levels (p = .0130) were recorded after CT-HSCT, especially after myeloablative conditioning.

CONCLUSION

The clinical follow-up data demonstrate no effect related to the biopsy procedure, but a substantial risk for impaired gonadal development after high-risk gonadotoxic treatment, in particular myeloablative CT-HSCT. Longer follow-up studies with a larger study population are needed to confirm these preliminary findings.

Fertility preservation in pediatric healthcare: a review

Survival rates for children and adolescents diagnosed with malignancy have been steadily increasing due to advances in oncology treatments. These treatments can have a toxic effect on the gonads. Currently, oocyte and sperm cryopreservation are recognized as well-established and successful strategies for fertility preservation for pubertal patients, while the use of gonadotropin-releasing hormone agonists for ovarian protection is controversial. For prepubertal girls, ovarian tissue cryopreservation is the sole option. However, the endocrinological and reproductive outcomes after ovarian tissue transplantation are highly heterogeneous. On the other hand, immature testicular tissue cryopreservation remains the only alternative for prepubertal boys, yet it is still experimental. Although there are several published guidelines for navigating fertility preservation for pediatric and adolescent patients as well as transgender populations, it is still restricted in clinical practice. This review aims to discuss the indications and clinical outcomes of fertility preservation. We also discuss the probably effective and efficient workflow to facilitate fertility preservation.

A comprehensive review and update on human fertility cryopreservation methods and tools

The broad conceptualization of fertility preservation and restoration has become already a major concern in the modern western world since a large number of individuals often face it in the everyday life. Driven by different health conditions and/or social reasons, a variety of patients currently rely on routinely and non-routinely applied assisted reproductive technologies, and mostly on the possibility to cryopreserve gametes and/or gonadal tissues for expanding their reproductive lifespan. This review embraces the data present in human-focused literature regarding the up-to-date methodologies and tools contemporarily applied in IVF laboratories' clinical setting of the oocyte, sperm, and embryo cryopreservation and explores the latest news and issues related to the optimization of methods used in ovarian and testicular tissue cryopreservation.

Biomaterials for Testicular Bioengineering: How far have we come and where do we have to go?

Traditional therapeutic interventions aim to restore male fertile potential or preserve sperm viability in severe cases, such as semen cryopreservation, testicular tissue, germ cell transplantation and testicular graft. However, these techniques demonstrate several methodological, clinical, and biological limitations, that impact in their results. In this scenario, reproductive medicine has sought biotechnological alternatives applied for infertility treatment, or to improve gamete preservation and thus increase reproductive rates in vitro and in vivo. One of the main approaches employed is the biomimetic testicular tissue reconstruction, which uses tissue-engineering principles and methodologies. This strategy pursues to mimic the testicular microenvironment, simulating physiological conditions. Such approach allows male gametes maintenance in culture or produce viable grafts that can be transplanted and restore reproductive functions. In this context, the application of several biomaterials have been proposed to be used in artificial biological systems. From synthetic polymers to decellularized matrixes, each biomaterial has advantages and disadvantages regarding its application in cell culture and tissue reconstruction. Therefore, the present review aims to list the progress that has been made and the continued challenges facing testicular regenerative medicine and the preservation of male reproductive capacity, based on the development of tissue bioengineering approaches for testicular tissue microenvironment reconstruction.

The Role of Promyelocytic Leukemia Zinc Finger (PLZF) and Glial-Derived Neurotrophic Factor Family Receptor Alpha 1 (GFRα1) in the Cryopreservation of Spermatogonia Stem Cells

The cryopreservation of spermatogonia stem cells (SSCs) has been widely used as an alternative treatment for infertility. However, cryopreservation itself induces cryoinjury due to oxidative and osmotic stress, leading to reduction in the survival rate and functionality of SSCs. Glial-derived neurotrophic factor family receptor alpha 1 (GFRα1) and promyelocytic leukemia zinc finger (PLZF) are expressed during the self-renewal and differentiation of SSCs, making them key tools for identifying the functionality of SSCs. To the best of our knowledge, the involvement of GFRα1 and PLZF in determining the functionality of SSCs after cryopreservation with therapeutic intervention is limited. Therefore, the purpose of this review is to determine the role of GFRα1 and PLZF as biomarkers for evaluating the functionality of SSCs in cryopreservation with therapeutic intervention. Therapeutic intervention, such as the use of antioxidants, and enhancement in cryopreservation protocols, such as cell encapsulation, cryoprotectant agents (CPA), and equilibrium of time and temperature increase the expression of GFRα1 and PLZF, resulting in maintaining the functionality of SSCs. In conclusion, GFRα1 and PLZF have the potential as biomarkers in cryopreservation with therapeutic intervention of SSCs to ensure the functionality of the stem cells.

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.

Male fertility preservation and restoration strategies for patients undergoing gonadotoxic therapies†

Medical treatments for cancers or other conditions can lead to permanent infertility. Infertility is an insidious disease that impacts not only the ability to have a biological child but also the emotional well-being of the infertile individuals, relationships, finances, and overall health. Therefore, all patients should be educated about the effects of their medical treatments on future fertility and about fertility preservation options. The standard fertility preservation option for adolescent and adult men is sperm cryopreservation. Sperms can be frozen and stored for a long period, thawed at a later date, and used to achieve pregnancy with existing assisted reproductive technologies. However, sperm cryopreservation is not applicable for prepubertal patients who do not yet produce sperm. The only fertility preservation option available to prepubertal boys is testicular tissue cryopreservation. Next-generation technologies are being developed to mature those testicular cells or tissues to produce fertilization-competent sperms. When sperm and testicular tissues are not available for fertility preservation, inducing pluripotent stem cells derived from somatic cells, such as blood or skin, may provide an alternative path to produce sperms through a process call in vitro gametogenesis. This review describes standard and experimental options to preserve male fertility as well as the experimental options to produce functional spermatids or sperms from immature cryopreserved testicular tissues or somatic cells.

Spermatogonial Stem Cell-Based Therapies: Taking Preclinical Research to the Next Level

Fertility preservation via biobanking of testicular tissue retrieved from testicular biopsies is now generally recommended for boys who need to undergo gonadotoxic treatment prior to the onset of puberty, as a source of spermatogonial stem cells (SSCs). SSCs have the potential of forming spermatids and may be used for therapeutic fertility approaches later in life. Although in the past 30 years many milestones have been reached to work towards SSC-based fertility restoration therapies, including transplantation of SSCs, grafting of testicular tissue and various in vitro and ex vivo spermatogenesis approaches, unfortunately, all these fertility therapies are still in a preclinical phase and not yet available for patients who have become infertile because of their treatment during childhood. Therefore, it is now time to take the preclinical research towards SSC-based therapy to the next level to resolve major issues that impede clinical implementation. This review gives an outline of the state of the art of the effectiveness and safety of fertility preservation and SSC-based therapies and addresses the hurdles that need to be taken for optimal progression towards actual clinical implementation of safe and effective SSC-based fertility treatments in the near future.

Update on pediatric testicular germ cell tumors

BACKGROUND

Testicular germ cell tumors are uncommon tumors that are encountered by pediatric surgeons and urologists and require a knowledge of appropriate contemporary evaluation and surgical and medical management.

METHOD

A review of the recommended diagnostic evaluation and current surgical and medical management of children and adolescents with testicular germ cell tumors based upon recently completed clinical trials was performed and summarized in this article.

RESULTS

In this summary of childhood and adolescent testicular germ cell tumors, we review the initial clinical evaluation, surgical and medical management, risk stratification, results from recent prospective cooperative group studies, and clinical outcomes. A summary of recently completed clinical trials by pediatric oncology cooperative groups is provided, and best surgical practices are discussed.

CONCLUSIONS

Testicular germ cell tumors in children are rare tumors. International collaborations, data-sharing, and enrollment of patients at all stages and risk classifications into active clinical trials will enhance our knowledge of these rare tumors and most importantly improve outcomes of patients with testicular germ cell tumors.

LEVEL OF EVIDENCE

This is a review article of previously published and referenced level 1 and 2 studies, but also includes expert opinion level 5, represented by the American Pediatric Surgical Association Cancer Committee.

Testicular Tissue Banking for Fertility Preservation in Young Boys: Which Patients Should Be Included?

Due to the growing number of young patients at risk of germ cell loss, there is a need to preserve spermatogonial stem cells for patients who are not able to bank spermatozoa. Worldwide, more and more clinics are implementing testicular tissue (TT) banking programs, making it a novel, yet indispensable, discipline in the field of fertility preservation. Previously, TT cryopreservation was predominantly offered to young cancer patients before starting gonadotoxic chemo- or radiotherapy. Nowadays, most centers also bank TT from patients with non-malignant conditions who need gonadotoxic conditioning therapy prior to hematopoietic stem cell (HSCT) or bone marrow transplantation (BMT). Additionally, some centers include patients who suffer from genetic or developmental disorders associated with prepubertal germ cell loss or patients who already had a previous round of chemo- or radiotherapy. It is important to note that the surgical removal of TT is an invasive procedure. Moreover, TT cryopreservation is still considered experimental as restoration methods are not yet clinically available. For this reason, TT banking should preferably only be offered to patients who are at significant risk of becoming infertile. In our view, TT cryopreservation is recommended for young cancer patients in need of high-risk chemo- and/or radiotherapy, regardless of previous low-risk treatment. Likewise, TT banking is advised for patients with non-malignant disorders such as sickle cell disease, beta-thalassemia, and bone marrow failure, who need high-risk conditioning therapy before HSCT/BMT. TT retrieval during orchidopexy is also proposed for patients with bilateral cryptorchidism. Since patients with a medium- to low-risk treatment generally maintain their fertility, TT banking is not advised for this group. Also for Klinefelter patients, TT banking is not recommended as it does not give better outcomes than a testicular sperm extraction later in life.

A review of methods for preserving male fertility

Male infertility is responsible for 50% of men's health problems and has always been a concern for personal and social issues. A survey of global statistics suggests an increase in infertility rate as one of the critical issues documented in studies. There are different ways of maintaining fertility in men, depending on their age. In this paper, we review the preservation methods used for fertility treatment in Iran and other countries. Available data were reviewed from Google Scholar, PubMed, Scopus, Web of Science, IranMedex, MEDLIB, IranDoc and Scientific Information Database and searched for articles published up to 2018, using the medical subject heading (MeSH) terms for cryopreservation, sperm, testicular, spermatogonia stem cell, male infertility and/or Iranian and in the world, to provide evidence from evaluation of fertility preservation the methods. Based the search strategy, 274 manuscripts were found. After reviewing the titles, abstracts and manuscripts in their entirety, 119 articles were obtained and selected according to the eligibility criteria. The 85 studies mentioned above were divided into three categories (sperm, testis, and spermatogonia stem cells (SSCs)), and methods of fertility preservation were investigated. Ways to maintain male fertility were different depending on age, and included sperm, testicular, and SSC freezing. The number of studies on testicular tissue and SSCs was low for human samples, and more studies are still needed. Sperm freezing at infertility centres is the top for male fertility preservation.

Assessment of the architecture and integrity of frozen-thawed testicular tissue from (pre)pubertal boys with cancer

BACKGROUND

Testicular tissue freezing is proposed for fertility preservation to (pre)pubertal boys with cancer before highly gonadotoxic treatment. Studies accurately comparing human (pre)pubertal testicular tissue quality before freezing and after thawing are exceptional. No study has reported this approach in a systematic manner and routine care.

OBJECTIVES

To assess the impact of a control slow freezing protocol on testicular tissue architecture and integrity of (pre)pubertal boys after thawing.

MATERIALS AND METHODS

(Pre)pubertal boys (n = 87) with cancer from 8 Reproductive Biology Laboratories of the French CECOS network benefited from testicular tissue freezing before hematopoietic stem cell transplantation. Seminiferous tubule cryodamage was determined histologically by scoring morphological alterations and by quantifying intratubular spermatogonia and the expression of DNA replication and repair marker in frozen-thawed testicular fragments.

RESULTS

A significant increase in nuclear and epithelial score alterations was observed after thawing (p < 0.0001). The global lesional score remained lower than 1.5 and comparable to fresh testicular tissue. The number of intratubular spermatogonia and the expression of DNA replication and repair marker in spermatogonia and Sertoli cells did not vary significantly after thawing. These data showed the good preservation of the seminiferous tubule integrity and architecture after thawing, as previously reported in our studies performed in prepubertal mice and rats.

DISCUSSION

The current study reports, for the first time, the development of a semi-quantitative analysis of cryodamage in human (pre)pubertal testicular tissue, using a rapid and useful tool that can be proposed in routine care to develop an internal and external quality control for testicular tissue freezing. This tool can also be used when changing one or several parameters of the freezing-thawing procedure.

CONCLUSION

Control slow freezing protocol without seeding maintains the seminiferous tubule architecture and integrity, the concentration of spermatogonia and the expression of DNA replication and repair marker in spermatogonia and Sertoli cells after thawing.

Strategies for cryopreservation of testicular cells and tissues in cancer and genetic diseases

Cryopreservation of testicular cells and tissues is useful for the preservation and restoration of fertility in pre-pubertal males expecting gonadotoxic treatment for cancer and genetic diseases causing impaired spermatogenesis. A number of freezing and vitrification protocols have thus been tried and variable results have been reported in terms of cell viability spermatogenesis progression and the production of fertile spermatozoa. A few studies have also reported the production of live offspring from cryopreserved testicular stem cells and tissues in rodents but their replication in large animals and human have been lacking. Advancement in in vitro spermatogenesis system has improved the possibility of producing fertile spermatozoa from the cryopreserved testis and has reduced the dependency on transplantation. This review provides an update on various cryopreservation strategies for fertility preservation in males expecting gonadotoxic treatment. It also discusses various methods of assessing and ameliorating cryoinjuries. Newer developments on in vitro spermatogenesis and testicular tissue engineering for in vitro sperm production from cryopreserved SSCs and testicular tissue are also discussed.

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

Patients with childhood, adolescent, and young adult cancer who will be treated with gonadotoxic therapies are at increased risk for infertility. Many patients and their families desire biological children but effective communication about treatment-related infertility risk and procedures for fertility preservation does not always happen. The PanCareLIFE Consortium and the International Late Effects of Childhood Cancer Guideline Harmonization Group reviewed the literature and developed a clinical practice guideline that provides recommendations for ongoing communication methods for fertility preservation for patients who were diagnosed with childhood, adolescent, and young adult cancer at age 25 years or younger and their families. Moreover, the guideline panel formulated considerations of the ethical implications that are associated with these procedures. Grading of Recommendations Assessment, Development and Evaluation methodology was used to grade the evidence and recommendations. In this clinical practice guideline, existing evidence and international expertise are combined to develop transparent recommendations that are easy to use to facilitate ongoing communication between health-care providers and patients with childhood, adolescent, and young adult cancer who might be at high risk for fertility impairment and their families.

Identifying and Meeting the Needs of Adolescents and Young Adults with Cancer

PURPOSE OF REVIEW

Adolescents and young adults (AYAs) with cancer are a vulnerable population with unique needs that are under-recognized and often overlooked by healthcare providers. This review focuses on identifying and meeting some of those needs including adherence to treatment, financial implications, impact on fertility and intimacy, issues with work/school, isolation, challenges with re-entry, and long-term side effects and survivorship.

RECENT FINDINGS

Survival rates have not improved in adolescents and young adults with cancer at the same rate as in children and older adults (the so called "AYA gap"). Restricted or delayed access to care and inconsistent cancer treatment and follow-up care contribute to this. Importantly, fertility preservation options have broadened and efforts to provide age appropriate counseling prior to treatment have improved. Additionally, AYAs face a variety of psychosocial issues while dealing with a cancer diagnosis during critical developmental years, and yet data pertaining to the successful identification and management of these issues is lacking. As a result, there has been recent increasing awareness that this patient population warrants strong advocates, additional research, and requires age group specific resources to be successful in navigating their cancer experience during treatment and into survivorship care. Members of the healthcare team should familiarize themselves with the unique needs of AYA cancer patients to provide optimal patient care. In order to build upon early progress, this group calls for additional study particularly when it comes to barriers to enrollment for AYA-specific research (including clinical trials), recognizing psychosocial needs (both during and after treatment), transition planning for returning to life after cancer, and managing long-term effects of treatment (including neuro cognitive changes). In addition, access to financial resources and appropriate mental health support needs to be improved.

Timing of spermatogonial stem cell transplantation affects the spermatogenic recovery outcome in mice

Spermatogonial stem cell transplantation (SSCT) is a strategy that has demonstrated to be feasible to restore spermatogenesis in animal models when it is performed shortly after the gonadotoxic onset to destroy their endogenous germ cells. However, in the case of boys subjected to fertility preservation, future transplantations will be performed with a delay of many years. In order to study how timing of SSCT affects donor-derived spermatogenic recovery in mice, we compared the percentage of spermatogenic tubule cross-sections within testes of 59 C57BL/6NCrl mice distributed in 6 groups: group 1, untreated mice controls (n = 9); group 2, mice that received a single dose of busulfan 40 mg/kg (n = 10); group 3, mice that received two additional doses of busulfan 10 mg/kg every 5 weeks (n = 10); group 4 (SSCT-A), mice subjected to a standard SSCT performed 5 weeks after a single injection of busulfan 40 mg/kg (n = 10); group 5 (SSCT-B), mice subjected to a delayed SSCT performed 15 weeks after a single injection of busulfan 40 mg/kg (n = 10); and group 6 (SSCT-C), mice subjected to a delayed SSCT with two additional doses of busulfan 10 mg/kg every 5 weeks (n = 10). Spermatogenic recovery in standard SSCT-A and SSCT-C groups ranged between 22.29 and 22.65%, compared with a lower recovery rate of 11.54% showed in the SSCT-B group. However, donor contribution resulted higher in standard SSCT-A, representing a 69.71% of cross-sections, compared with the rest of conditions ranging from 34.69 to 35.42%. Overall, we concluded that a delay in the SSCT from the gonadotoxic onset decreases the efficiency of donor-derived spermatogenic recovery in mice.

Fertility preservation for prepubertal boys: lessons learned from the past and update on remaining challenges towards clinical translation

BACKGROUND

Childhood cancer incidence and survivorship are both on the rise. However, many lifesaving treatments threaten the prepubertal testis. Cryopreservation of immature testicular tissue (ITT), containing spermatogonial stem cells (SSCs), as a fertility preservation (FP) option for this population is increasingly proposed worldwide. Recent achievements notably the birth of non-human primate (NHP) progeny using sperm developed in frozen-thawed ITT autografts has given proof of principle of the reproductive potential of banked ITT. Outlining the current state of the art on FP for prepubertal boys is crucial as some of the boys who have cryopreserved ITT since the early 2000s are now in their reproductive age and are already seeking answers with regards to their fertility.

OBJECTIVE AND RATIONALE

In the light of past decade achievements and observations, this review aims to provide insight into relevant questions for clinicians involved in FP programmes. Have the indications for FP for prepubertal boys changed over time? What is key for patient counselling and ITT sampling based on the latest achievements in animals and research performed with human ITT? How far are we from clinical application of methods to restore reproductive capacity with cryostored ITT?

SEARCH METHODS

An extensive search for articles published in English or French since January 2010 to June 2020 using keywords relevant to the topic of FP for prepubertal boys was made in the MEDLINE database through PubMed. Original articles on fertility preservation with emphasis on those involving prepubertal testicular tissue, as well as comprehensive and systematic reviews were included. Papers with redundancy of information or with an absence of a relevant link for future clinical application were excluded. Papers on alternative sources of stem cells besides SSCs were excluded.

OUTCOMES

Preliminary follow-up data indicate that around 27% of boys who have undergone testicular sampling as an FP measure have proved azoospermic and must therefore solely rely on their cryostored ITT to ensure biologic parenthood. Auto-transplantation of ITT appears to be the first technique that could enter pilot clinical trials but should be restricted to tissue free of malignant cells. While in vitro spermatogenesis circumvents the risk linked to cancer cell contamination and has led to offspring in mice, complete spermatogenesis has not been achieved with human ITT. However, generation of haploid germ cells paves the way to further studies aimed at completing the final maturation of germ cells and increasing the efficiency of the processes.

WIDER IMPLICATIONS

Despite all the research done to date, FP for prepubertal boys remains a relatively young field and is often challenging to healthcare providers, patients and parents. As cryopreservation of ITT is now likely to expand further, it is important not only to acknowledge some of the research questions raised on the topic, e.g. the epigenetic and genetic integrity of gametes derived from strategies to restore fertility with banked ITT but also to provide healthcare professionals worldwide with updated knowledge to launch proper multicollaborative care pathways in the field and address clinical issues that will come-up when aiming for the child's best interest.

Pediatric oncofertility: an update

Fertility preservation (FP) in pediatric patients with cancer is an evolving field. In this review, we give a short update on recent scientific advances in the practice of pediatric oncofertility, particularly related to the research involving gonadal tissue cryopreservation from prepubertal patients, which remains experimental. We then focus on recent advances in the implementation of formal pediatric oncofertility programs and barriers in the delivery of FP in this patient population. Finally, we include some of the more recent outcomes data from established oncofertility programs that treat pediatric patients.

Histologic Analysis of Testes from Prepubertal Patients Treated with Chemotherapy Associates Impaired Germ Cell Counts with Cumulative Doses of Cyclophosphamide, Ifosfamide, Cytarabine, and Asparaginase

Cryopreservation of immature testicular tissue is an experimental strategy for the preservation of fertility in prepubertal boys that will be subjected to a gonadotoxic onset, as is the case of oncologic patients. Therefore, the objective of this study was to assess the impact of chemotherapeutic treatments on the testicular histologic phenotype in prepubertal patients. A total of 56 testicular tissue samples from pediatric patients between 0 and 16 years old (28 with at least one previous chemotherapeutic onset and 28 untreated controls) were histologically analyzed and age-matched compared. At least two 5-μm sections from testis per patient separated by a distance of 100 μm were immunostained for the germ cell marker VASA, the spermatogonial markers UTF1, PLZF, UCHL1, and SALL4, the marker for proliferative cells KI67, and the Sertoli cell marker SOX9. The percentage of tubule cross-sections positive for each marker and the number of positive cells per tubule cross-section were determined and association with the cumulative dose received of each chemotherapeutic drug was statistically assessed. Results indicated that alkylating agents, cyclophosphamide and ifosfamide, but also the antimetabolite cytarabine and asparaginase were associated with a decreased percentage of positive tubules and a lower number of positive cells per tubule for the analyzed markers. Our results provide new evidences of the potential of chemotherapeutic agents previously considered to have low gonadotoxic effects such as cytarabine and asparaginase to trigger a severe testicular phenotype, hampering the potential success of future fertility restoration in experimental programs of fertility preservation in prepubertal boys.

A prospective study on the long-term outcome of prepubertal and pubertal boys undergoing testicular biopsy for fertility preservation prior to hematologic stem cell transplantation

BACKGROUND

Few studies have reported the long-term outcomes of prepubertal and pubertal boys undergoing testicular biopsy for fertility preservation (FP).

PROCEDURE

This prospective longitudinal study examined 21 boys (aged 1.5-14.5 years) who underwent testicular biopsy for FP prior to allogeneic (n = 20) or autologous (n = 1) hematological stem cell transplantation (HSCT) between 2003 and 2010. During counseling, pubertal boys were encouraged to produce a sperm sample by masturbation , while prepubertal boys were presented with surgical testicular tissue retrieval as an option for experimental FP. Clinical outcomes included postoperative complications, pubertal development, and sex-hormone levels. Survivors approaching adulthood were encouraged to provide semen samples.

RESULTS

Twenty boys, including 14 in prepuberty and six in early puberty (Tanner stage 2-3), underwent open testicular biopsies. Two pubertal biopsies contained mature sperms, which were cryopreserved. Testicular tissue was vitrified in the remaining 18 cases. One pubertal boy (Tanner stage 4) underwent percutaneous testicular sperm aspiration and sperms obtained were cryopreserved. Postoperative complications (hematoma or infection) were rare. Overall, 14 boys survived >5 years (mean follow-up after HSCT, 7.2 years) and 11 showed advanced puberty. Semen samples were provided by five boys and obtained sperm were cryopreserved from two. Individuals at adulthood had normal testosterone levels but subnormal testicular size, high follicle stimulating hormone, and low inhibin B and anti-Müllerian hormone levels.

CONCLUSION

No long-term risks were detected during continuous clinical follow-up. Experimental testicular biopsies for FP were well accepted by the patients and families, despite the absence of methods to use prepubertal tissue for fertility treatment.

Fertility preservation in boys: recent developments and new insights †

BACKGROUND

Infertility is an important side effect of treatments used for cancer and other non-malignant conditions in males. This may be due to the loss of spermatogonial stem cells (SSCs) and/or altered functionality of testicular somatic cells (e.g. Sertoli cells, Leydig cells). Whereas sperm cryopreservation is the first-line procedure to preserve fertility in post-pubertal males, this option does not exist for prepubertal boys. For patients unable to produce sperm and at high risk of losing their fertility, testicular tissue freezing is now proposed as an alternative experimental option to safeguard their fertility.

OBJECTIVE AND RATIONALE

With this review, we aim to provide an update on clinical practices and experimental methods, as well as to describe patient management inclusion strategies used to preserve and restore the fertility of prepubertal boys at high risk of fertility loss.

SEARCH METHODS

Based on the expertise of the participating centres and a literature search of the progress in clinical practices, patient management strategies and experimental methods used to preserve and restore the fertility of prepubertal boys at high risk of fertility loss were identified. In addition, a survey was conducted amongst European and North American centres/networks that have published papers on their testicular tissue banking activity.

OUTCOMES

Since the first publication on murine SSC transplantation in 1994, remarkable progress has been made towards clinical application: cryopreservation protocols for testicular tissue have been developed in animal models and are now offered to patients in clinics as a still experimental procedure. Transplantation methods have been adapted for human testis, and the efficiency and safety of the technique are being evaluated in mouse and primate models. However, important practical, medical and ethical issues must be resolved before fertility restoration can be applied in the clinic.Since the previous survey conducted in 2012, the implementation of testicular tissue cryopreservation as a means to preserve the fertility of prepubertal boys has increased. Data have been collected from 24 co-ordinating centres worldwide, which are actively offering testis tissue cryobanking to safeguard the future fertility of boys. More than 1033 young patients (age range 3 months to 18 years) have already undergone testicular tissue retrieval and storage for fertility preservation.

LIMITATIONS REASONS FOR CAUTION

The review does not include the data of all reproductive centres worldwide. Other centres might be offering testicular tissue cryopreservation. Therefore, the numbers might be not representative for the entire field in reproductive medicine and biology worldwide. The key ethical issue regarding fertility preservation in prepubertal boys remains the experimental nature of the intervention.

WIDER IMPLICATIONS

The revised procedures can be implemented by the multi-disciplinary teams offering and/or developing treatment strategies to preserve the fertility of prepubertal boys who have a high risk of fertility loss.

STUDY FUNDING/COMPETING INTERESTS

The work was funded by ESHRE. None of the authors has a conflict of interest.

Progress in translational reproductive science: testicular tissue transplantation and in vitro spermatogenesis

Since the birth of the first child conceived via in vitro fertilization 40 years ago, fertility treatments and assisted reproductive technology have allowed many couples to reach their reproductive goals. As of yet, no fertility options are available for men who cannot produce functional sperm, but many experimental therapies have demonstrated promising results in animal models. Both autologous (stem cell transplantation, de novo morphogenesis, and testicular tissue grafting) and outside-the-body (xenografting and in vitro spermatogenesis) approaches exist for restoring sperm production in infertile animals with varying degrees of success. Once safety profiles are established and an ideal patient population is chosen, some of these techniques may be ready for human experimentation in the near future, with likely clinical implementation within the next decade.

Fertility-related services in pediatric oncology across the cancer continuum: a clinic overview

PURPOSE

Fertility-related services in pediatric oncology are increasing, but barriers to care remain and few structured programs are described in the literature. Therefore, the study objectives were (1) to characterize fertility-related services in a large pediatric oncology center and (2) to discuss recommendations for fertility-related services across the pediatric cancer continuum.

METHODS

Medical records of all cases referred to our Fertility Preservation Clinic within a 3-year period were reviewed, which included 292 patients/survivors with malignant disease. Approximately half (n = 152/292, 52.1%) were cancer patients referred prior to treatment (n = 92/152) or while on active therapy (n = 60/152). The other half (n = 140/292; 47.9%) were survivors who had completed treatment.

RESULTS

Referrals more than doubled over 3 years. Most patients referred before treatment were offered and opted for FP (72.8% attempted; 58.9% completed). More male than female patients opted for FP (77.6% vs. 22.4%), but completion rates were higher among females (93.3% vs. 76.9%). Rates of FP before treatment did not increase over time (p = .752). Many patients on-treatment were referred for infertility risk counseling, demonstrating information/support needs in this group. Referred survivors questioned their fertility post-treatment and completed fertility assessments, indicating intact fertility among few (~ 15%).

CONCLUSIONS

This review demonstrated the acceptance and increasing need for fertility-related services in pediatric oncology across the cancer continuum, including FP before treatment, counseling during treatment, and fertility assessment in survivorship. Based on our experiences, current recommendations are discussed and include standardized procedures, streamlined referrals, adequate communication/education (of providers and families), and meeting specific needs of young cancer patients/survivors.

Setting Up a Cryopreservation Programme for Immature Testicular Tissue: Lessons Learned After More Than 15 Years of Experience

Young boys undergoing gonadotoxic treatments are at high risk of spermatogonial stem cell (SSC) loss and fertility problems later in life. Stem cell loss can also occur in specific genetic conditions, eg, Klinefelter syndrome (KS). Before puberty, these boys do not yet produce sperm. Hence, they cannot benefit from sperm banking. An emerging alternative is the freezing of testicular tissue aiming to preserve the SSCs for eventual autologous transplantation or in vitro maturation at adult age. Many fertility preservation programmes include cryopreservation of immature testicular tissue, although the restoration procedures are still under development. Until the end of 2018, the Universitair Ziekenhuis Brussel has frozen testicular tissues of 112 patients between 8 months and 18 years of age. Testicular tissue was removed in view of gonadotoxic cancer treatment (35%), gonadotoxic conditioning therapy for bone marrow transplantation (35%) or in boys diagnosed with KS (30%). So far, none of these boys had their testicular tissue transplanted back. This article summarizes our experience with cryopreservation of immature testicular tissue over the past 16 years (2002-2018) and describes the key issues for setting up a cryopreservation programme for immature testicular tissue as a means to safeguard the future fertility of boys at high risk of SSC loss.

Fertility preservation knowledge, attitudes and intentions among children by proxy and adolescents with cancer

RESEARCH QUESTION

The current study aimed to assess knowledge, attitudes and intentions in relation to fertility preservation among children, by proxy, and adolescents with cancer. Although fertility preservation options have been developed to mitigate the adverse long-term effects of life-saving cancer treatment on fertility, fertility is difficult for children and adolescents to conceptualize, especially when they face a cancer diagnosis.

DESIGN

This was a descriptive, semi-quantitative analysis. Adolescents and parents of children or adolescents within 6 months of a cancer diagnosis and undergoing gonadotoxic treatment were invited to participate. Seventy-one families completed and returned the study's questionnaire (91 questionnaires) over a period of 26 months.

RESULTS

The vast majority of participants were aware of the gonadotoxic effects of cancer treatment (85%) and had positive attitudes towards fertility preservation (>90%), but only a portion of them (20%) were willing to take action towards this goal. Although adolescent-parent pairs had similar attitudes towards fertility preservation, adolescents tended to be more sceptical about experimental fertility preservation options. Male post-pubertal cancer patients were more likely to be offered fertility preservation counselling or referral to a specialist in comparison to their younger and female counterparts.

CONCLUSIONS

Fertility preservation care has advanced but there are still gender and age differences in counselling and treatment initiation in the paediatric and adolescent cancer population. Interventions to improve provider-patient-parent communication regarding fertility preservation and to help patients address the observed intention-behaviour gap in relation to fertility preservation options are needed.

Testicular wedge biopsy for fertility preservation in children at significant risk for azoospermia after gonadotoxic therapy

BACKGROUND/PURPOSE

Testicular tissue cryopreservation (TTC) provides an experimental option for fertility preservation for male children at significant risk for azoospermia owing to high-risk gonadotoxic treatments.

METHODS

A single institution, retrospective review of TTC cases from 2015 to 2017. Children at significant risk for azoospermia were eligible for study inclusion. A unilateral wedge biopsy of the testis was performed for TTC.

RESULTS

TTC was performed in 23 patients. Average age was 10 years old (5 months to 18 years). Diagnoses included solid tumor (74%, n = 17), hematologic malignancy (17%, n = 4), and benign hematologic disease (13%, n = 3). Six patients had TTC at the time of disease relapse. Nine patients were referred for TTC prior to stem cell transplantation. The majority (70%, n = 16) of patients had an additional procedure at the time of TTC. One patient developed postoperative scrotal cellulitis that was treated with antibiotics. The majority of patients (96%, n = 22) had normal testicular tissue with the presence of germ cells on histopathological analysis. Median time to start of medical therapy was seven days with no unanticipated treatment delays.

CONCLUSIONS

Testicular wedge biopsy for TTC can be performed safely, coordinated with other necessary procedures, and does not delay the start of treatment. TTC remains an experimental option for fertility preservation for children, as no spermatogenic recovery or pregnancies from cryopreserved testicular tissues have been reported to date.

LEVEL OF EVIDENCE

IV.

Adolescent male fertility following reduced-intensity conditioning regimen for hematopoietic stem cell transplantation in non-malignant disorders

INTRODUCTION

The effects of RIC for HSCT on male fertility remain unknown. We investigated spermatogenesis and gonadal hormonal status among adolescent male patients who received RIC HSCT for non-malignant diseases.

PATIENTS AND METHODS

Patients with non-malignant disease who had undergone a RIC HSCT were recruited and evaluated for spermatogenesis via semen analysis and gonadal hormonal function via serum hormone levels. Those who had received prior chemotherapy or radiation were excluded from the study. We reviewed the charts to record demographic factors, conditioning regimen and complications during and after transplant.

RESULTS

Five patients were enrolled. The median age at the time of transplant was 15 years (range, 11-19 years), and the median time between bone marrow transplant and semen analysis was 5 years (range, 3-11 years). Median age of patients was 20 years (range, 18-25 years) at the time of the study. Serum FSH and LH levels were elevated in four patients, and inhibin B levels were low for age in three patients. Semen analysis showed two patients had azoospermia, and the remaining three patients showed severe oligozoospermia. Normal morphology and motility were seen in only one patient.

CONCLUSION

This case series suggests that RIC transplants may be associated with impaired spermatogenesis and sequential follow-up is necessary given the potential for either permanent impairment or delayed recovery. Further larger studies are needed to confirm these findings.

Gene expression analysis of ovine prepubertal testicular tissue vitrified with a novel cryodevice (E.Vit)

PURPOSE

Testicular tissue cryopreservation prior to gonadotoxic therapies is a method to preserve fertility in children. However, the technique still requires development, especially when the tissue is immature and rather susceptible to stress derived from in vitro manipulation. This study aimed to investigate the effects of vitrification with a new cryodevice (E.Vit) on cell membrane integrity and gene expression of prepubertal testicular tissue in the ovine model.

METHODS

Pieces of immature testicular tissue (1 mm³) were inserted into "E.Vit" devices and vitrified with a two-step protocol. After warming, tissues were cultured in vitro and cell membrane integrity was assessed after 0, 2, and 24 h by trypan blue exclusion test. Controls consisted of non-vitrified tissue analyzed after 0, 2, and 24 h in vitro culture (IVC). Expression of genes involved in transcriptional stress response (BAX, SOD1, CIRBP, HSP90AB1), cell proliferation (KIF11), and germ- (ZBDB16, TERT, POU5F1, KIT) and somatic- (AR, FSHR, STAR) cell specific markers was evaluated 2 and 24 h after warming.

RESULTS

Post-warming trypan blue staining showed the survival of most cells, although membrane integrity immediately after warming (66.00% ± 4.73) or after 2 h IVC (59.67% ± 4.18) was significantly lower than controls (C0h 89.67% ± 1.45). Extended post-warming IVC (24 h) caused an additional decrease to 31% ± 3.46 (P < 0.05). Germ- and somatic-cell specific markers showed the survival of both cell types after cryopreservation and IVC. All genes were affected by cryopreservation and/or IVC, and moderate stress conditions were indicated by transcriptional stress response.

CONCLUSIONS

Vitrification with the cryodevice E.Vit is a promising strategy to cryopreserve prepubertal testicular tissue.

Satisfaction, disappointment and regret surrounding fertility preservation decisions in the paediatric and adolescent cancer population

PURPOSE

With over 80% of paediatric and adolescent cancer patients surviving into adulthood, quality-of-life issues such as future fertility are increasingly important. However, little is known about regret around decisions to pursue or forgo fertility preservation (FP). We investigated the risk of decision regret in families involved in making a FP decision and explored contributive factors.

METHODS

Parents and patients ≥ 15 years were invited to participate. Participants completed a 10-item survey, including a validated Decision Regret Scale. Scores ≥ 30 indicated high regret. Free-text response items allowed participants to provide reasons for satisfaction or regret.

RESULTS

A total of 108 parents and 30 patients participated. Most (81.4%) reported low regret (mean score 13.7). On multivariate analysis, predictors of low regret included having a FP procedure and a fertility discussion pre-treatment. Most participants believed that FP offers hope for future fertility. Some reported dissatisfaction with the process of decision-making.

CONCLUSION

Overall levels of regret in the study population were low, with factors associated with quality, timely discussion and belief in the success of FP technology being predictors of low regret. However, dissatisfaction with the decision-making process itself revealed that refinements to the programme are required to meet families' needs.

Spermatogonial stem cells

Spermatogonial stem cells (SSCs) are the most primitive spermatogonia in the testis and have an essential role to maintain highly productive spermatogenesis by self-renewal and continuous generation of daughter spermatogonia that differentiate into spermatozoa, transmitting genetic information to the next generation. Since the 1950s, many experimental methods, including histology, immunostaining, whole-mount analyses, and pulse-chase labeling, had been used in attempts to identify SSCs, but without success. In 1994, a spermatogonial transplantation method was reported that established a quantitative functional assay to identify SSCs by evaluating their ability to both self-renew and differentiate to spermatozoa. The system was originally developed using mice and subsequently extended to nonrodents, including domestic animals and humans. Availability of the functional assay for SSCs has made it possible to develop culture systems for their ex vivo expansion, which dramatically advanced germ cell biology and allowed medical and agricultural applications. In coming years, SSCs will be increasingly used to understand their regulation, as well as in germline modification, including gene correction, enhancement of male fertility, and conversion of somatic cells to biologically competent male germline cells.

Influence of temperature, serum, and gonadotropin supplementation in short- and long-term organotypic culture of human immature testicular tissue

OBJECTIVE

To study how temperature, serum, and gonadotropin supplementation affect the organotypic culture of human immature testicular tissue (ITT) in vitro.

DESIGN

Experimental basic science study.

SETTING

Reproductive biology laboratory.

PATIENT(S)

ITT from 4 boys with cancer that had testicular tissue cryopreserved as part of their fertility preservation treatment.

INTERVENTION(S)

In vitro organotypic culture of ITT, exposed to different temperatures (37°C vs. 34°C), serum (fetal bovine serum [FBS] vs. Knockout Serum Replacement [KOS]), and gonadotropin supplementation (with and without FSH and LH).

MAIN OUTCOME MEASURE(S)

Characterization of the tissue was performed at days 0, 14, and 70 with the use of reverse-transcription quantitative polymerase chain reaction, terminal deoxynucleotide transferase-mediated dUTP nick-end labeling, histologic analysis by means of hematoxylin-eosin staining, and immunohistochemical staining. Hormonal secretion was determined at days 3, 14, 28, and 70 by means of immunofluorescent assay.

RESULT(S)

The 37°C conditions showed an accelerated loss of tubular morphology and higher intratubular apoptosis. KOS supplementation triggered the up-regulation of STAR, SOX9, DAZL, DDX4, PLZF, and UTF1, the percentage of SOX9+/androgen receptor (AR)-positive mature Sertoli cells at day 14, and testosterone secretion. Gonadotropin supplementation increased the numbers of both undifferentiated UTF1+ spermatogonia and premeiotic VASA+/SYCP3+ spermatogonia at day 14, and the number of SOX9+ Sertoli cells at day 70. The low SOX9+/AR+ colocalization, the disorganized pattern of ZO-1, and the progressive decrease of antimüllerian hormone secretion indicated inefficient Sertoli cell maturation in vitro.

CONCLUSION(S)

The 34°C condition in KOS showed the best results for the survival of both spermatogonia and Sertoli cells. FSH/LH supplementation also improved long-term survival of Sertoli cells and the maturation of spermatogonia up to meiotic initiation in short-term culture.

Cryostorage of testicular tissue and retransplantation of spermatogonial stem cells in the infertile male

Transplantation of own cryostored spermatogonial stem cells (SSCs) is a promising technique for fertility restoration when the SSC pool has been depleted. In this regard, cryopreservation of pre-pubertal testicular tissue or SSCs suspensions before gonadotoxic therapies is ethically accepted and increasingly proposed. SSC transplantation has also been considered to treat other causes of infertility relying on the possibility of propagating SSCs retrieved in the testes of infertile men before autologous re-transplantation. Although encouraging results were achieved in animals and in preclinical experiments, clinical perspectives are still limited by a number of unresolved technical and safety issues, such as the risk of cancer cell contamination of cells intended for transplantation and the genetic and epigenetic stability of SCCs when cultured before re-transplantation. Moreover, while genome editing techniques raise the hope of modifying the SSCs genome before re-transplantation, their application for reproductive purposes might be a step too far for the moment.

Fertility Issues in Pediatric Urology

Improved understanding of the pathogenesis and natural history of many urologic disorders, as well as advances in fertility preservation techniques, has increased the awareness of and options for management of fertility threats in pediatric patients. In children, fertility may be altered by oncologic conditions, by differences in sexual differentiation, by gonadotoxic drugs and other side effects of treatment for nonurologic disorders, and by urologic conditions, such as varicocele and cryptorchidism. Although fertility concerns are best addressed in a multidisciplinary setting, pediatric urologists should be aware of the underlying pathophysiology and management options to properly counsel and advocate for patients.

Ovarian tissue cryopreservation (OTC) in prepubertal girls and young women: an analysis of parents' and patients' decision-making

PURPOSE

The purpose of this study was to explore the decision-making influences, perceived level of control over decision-making, and mood states of parents and patients who were offered OTC prior to gonadotoxic therapy.

METHODS

Parents and patients, at least 12 years old, who required gonadotoxic therapy and were offered OTC prior to therapy, were asked to complete questionnaires. Two validated instruments were also used: the Decision-Making Control Instrument (DMCI) and the Profile of Mood States (POMS). The factors that influenced decision-making were compared using Student's t test, and the scores of DMCI and POMS were compared using the Mann-Whitney test.

RESULTS

Thirty-six parents and 16 patients who elected ovarian tissue cryopreservation (OTC) completed questionnaires. Five parents who declined OTC also completed questionnaires. Accepters thought OTC was a good idea and that, in the future, science would enable cryopreserved ovarian tissue to be used to restore fertility (100% parents, 93.8% patients). Among accepters, the desire for genetically related children and prevention of the stress of infertility drove parents' and patients' decisions (90.9 and 100%, respectively). The desire to prevent the stress of infertility was important to parents, but patients were less likely to report that a desire to prevent the stress of infertility factored into their decision-making (66.7 vs. 50.0%; p < 0.001). All respondents felt in control of their decision and displayed low levels of mood disturbance.

CONCLUSIONS

Though the decision to undergo experimental OTC is difficult and often urgent, this study suggests that families feel in control of their decision-making and report little emotional disturbance.

Fertility preservation options in pediatric and adolescent patients with cancer

The incidence of childhood cancer has steadily increased since the 1950s, with approximately 16,000 children diagnosed each year. However, with the advent of more effective multimodal therapies, childhood cancer survival rates have continued to improve over the past 40 years, with >80% of patients now surviving into adulthood. Fertility preservation (FP) has become an important quality-of-life issue for many survivors of childhood cancer. As a result, the therapeutic options have become less gonadotoxic over time and more patients are being offered FP options. This review examines the indications for consultation, male and female FP options both in the prepubertal patient and adolescent patient, and the unique ethical issues surrounding FP in this vulnerable population. Cancer 2018;124:1867-76. © 2018 American Cancer Society.

Tissue Engineering to Improve Immature Testicular Tissue and Cell Transplantation Outcomes: One Step Closer to Fertility Restoration for Prepubertal Boys Exposed to Gonadotoxic Treatments

Despite their important contribution to the cure of both oncological and benign diseases, gonadotoxic therapies present the risk of a severe impairment of fertility. Sperm cryopreservation is not an option to preserve prepubertal boys’ reproductive potential, as their seminiferous tubules only contain spermatogonial stem cells (as diploid precursors of spermatozoa). Cryobanking of human immature testicular tissue (ITT) prior to gonadotoxic therapies is an accepted practice. Evaluation of cryopreserved ITT using xenotransplantation in nude mice showed the survival of a limited proportion of spermatogonia and their ability to proliferate and initiate differentiation. However, complete spermatogenesis could not be achieved in the mouse model. Loss of germ cells after ITT grafting points to the need to optimize the transplantation technique. Tissue engineering, a new branch of science that aims at improving cellular environment using scaffolds and molecules administration, might be an approach for further progress. In this review, after summarizing the lessons learned from human prepubertal testicular germ cells or tissue xenotransplantation experiments, we will focus on the benefits that might be gathered using bioengineering techniques to enhance transplantation outcomes by optimizing early tissue graft revascularization, protecting cells from toxic insults linked to ischemic injury and exploring strategies to promote cellular differentiation.

Development of a Cytocompatible Scaffold from Pig Immature Testicular Tissue Allowing Human Sertoli Cell Attachment, Proliferation and Functionality

Cryopreservation of immature testicular tissue before chemo/radiotherapy is the only option to preserve fertility of cancer-affected prepubertal boys. To avoid reintroduction of malignant cells, development of a transplantable scaffold by decellularization of pig immature testicular tissue (ITT) able to support decontaminated testicular cells could be an option for fertility restoration in these patients. We, therefore, compared decellularization protocols to produce a cytocompatible scaffold. Fragments of ITT from 15 piglets were decellularized using three protocols: sodium dodecyl sulfate (SDS)-Triton (ST), Triton-SDS-Triton (TST) and trypsin 0.05%/ethylenediaminetetraacetic acid (EDTA) 0.02%-Triton (TET) with varying detergent concentrations. All protocols were able to lower DNA levels. Collagen retention was demonstrated in all groups except ST 1%, and a significant decrease in glycosaminoglycans was observed in the TST 1% and TET 1% groups. When Sertoli cells (SCs) were cultured with decellularized tissue, no signs of cytotoxicity were detected. A higher SC proliferation rate and greater stem cell factor secretion were observed than with SCs cultured without scaffold. ST 0.01% and TET 3% conditions offered the best compromise in terms of DNA elimination and extracellular matrix (ECM) preservation, while ensuring good attachment, proliferation and functionality of human SCs. This study demonstrates the potential of using decellularized pig ITT for human testicular tissue engineering purposes.

A short report on current fertility preservation strategies for boys

BACKGROUND

Advances in cancer treatment have led to improved long-term survival after childhood cancer, but often at a price of impaired future fertility. Fertility preservation (FP) in male children and early adolescents poses unique challenges as efficacy is unproven.

OBJECTIVES

To describe characteristics of testicular tissue cryopreservation (TTCP) specimens taken from paediatric and adolescent patients, stratified by age, and prior chemotherapy, if any, and to demonstrate evidence for germ cells.

MATERIALS AND METHODS

Retrospective review of gonadal biopsies and clinical records of patients consented into the Royal Children's Hospital FP programme between 1987 and 2015. Tissue was sliced into blocks, with one section sent for histopathology prior to cryopreservation. In boys ≥12 years where spermatogenesis could be expected, a portion of tissue was disaggregated completely to look for mature sperm and if found, additional tissue was dissected and the resulting suspension frozen.

RESULTS

Testicular tissue cryopreservation specimens in 44 males (0.3-16.8 years) provided an average of 7.8 slices per patient. All the specimens were taken at the same time as another necessary surgical procedure, under one general anaesthesic. There was only one complication of scrotal wound dehiscence. Seven of the forty-four (15.9%) patients had chemotherapy prior to testicular biopsy, while the rest were chemotherapy naïve. Five of these were prepubertal, and two were pubertal patients. Eleven subjects had tissue dissected with mature sperm found in eight. Of these eight patients where sperm were found, all were pubertal with testicular size of more than 10 mL and showing histological evidence of spermatogenesis. No histologic specimen demonstrated any malignant cells.

CONCLUSIONS

Testicular tissue cryopreservation can be performed in young patients without delay, preferably prior to cancer treatment. As testicular tissue contains germ cells from which haploid spermatozoa are ultimately derived, future technologies may allow their utilization for fertility in humans. This may be the only hope for biological offspring in some patients undergoing fertility compromising treatment. Retrieval of mature sperm from some pubertal patients, however, offers realistic hope to these patients of future fertility.