Abstract For young patients receiving treatments that might impair their reproductive functions, gonadal tissue cryopreservation emerges as a technique to preserve their future fertility. The ...reimplantation of cryopreserved prepubertal gonadal tissue is currently the most promising strategy for restoring fertility in these individuals. There have been reports of successful births after autotransplanting ovarian tissue harvested at peri-puberty. In males, although autotransplantation of testicular tissue has not yet led to the production of viable sperm, successful reproduction has been documented in primate studies following such procedures. The preservation of gonadal tissue in the setting of cancer introduces concerns regarding the potential for malignant cell contamination, leading to worries about the future reimplantation of contaminated tissue. Recent analysis shows significant contamination rates with cancer cells in cryopreserved gonadal tissues from children with leukemia and lymphoma — 37% in testicular tissues and 12% in ovarian tissues. The risk of contamination extends beyond hematological cancers with documented cases of cancer cell contamination in ovarian tissue from patients with apparently localized sarcoma, and detection of neuroblastoma cells in cryopreserved testicular tissue. Such significant contamination rates prompt discussions about harvesting tissue post-chemotherapy, although gonadotoxic treatments may adversely affect the quality of the cryopreserved germ cells. Emerging diagnostic techniques, especially molecular methods, are being investigated for their ability to more accurately detect residual maliganat disease. While traditional histology and immunohistochemistry have been the norm, their sensitivity is relatively low. More precise molecular-genetic techniques, such as Polymerase Chain Reaction (PCR) and Reverse Transcriptase-quantitative PCR, demonstrate greater sensitivity. Moreover, advanced methods like next-generation sequencing offer even higher precision in detecting minimal residual disease. Xenotransplantation of gonadal tissue into immunodeficient animals may also provide some insights as a preclinical method for relapse prediction. Future research is essential to refine these diagnostic techniques to achieve the necessary sensitivity for clinical application. This presentation aims to explore the current knowledge on gonadal tissue contamination rates for both hematological cancers and solid tumors in prepubertal patients and to review strategies for decontaminating gonadal tissues. A critical examination of existing knowledge gaps will be conducted with the objective of identifying secure methods for fertility restoration in cancer survivors.
Abstract
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 INTEREST(S)
The work was funded by ESHRE. None of the authors has a conflict of interest.
Abstract
STUDY QUESTION
Does chemotherapy exposure (with or without alkylating agents) or primary diagnosis affect spermatogonial quantity in human prepubertal testicular tissue?
SUMMARY ANSWER
...Spermatogonial quantity is significantly reduced in testes of prepubertal boys treated with alkylating agent therapies or with hydroxyurea for sickle cell disease.
WHAT IS KNOWN ALREADY
Cryopreservation of spermatogonial stem cells, followed by transplantation into the testis after treatment, is a proposed clinical option for fertility restoration in children. The key clinical consideration behind this approach is a sufficient quantity of healthy cryopreserved spermatogonia. However, since most boys with malignancies start therapy with agents that are not potentially sterilizing, they will have already received some chemotherapy before testicular tissue cryopreservation is considered.
STUDY DESIGN, SIZE, DURATION
We examined histological sections of prepubertal testicular tissue to elucidate whether chemotherapy exposure or primary diagnosis affects spermatogonial quantity. Quantity of spermatogonia per transverse tubular cross-section (S/T) was assessed in relation to treatment characteristics and normative reference values in histological sections of paraffin embedded testicular tissue samples collected from 32 consecutive boy patients (aged 6.3 ± 3.8 mean ± SD years) between 2014 and 2017, as part of the NORDFERTIL study, and in 14 control samples (from boys aged 5.6 ± 5.0 mean ± SD years) from an internal biobank.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Prepubertal boys in Sweden, Finland and Iceland who were facing treatments associated with a very high risk of infertility, were offered the experimental procedure of testicular cryopreservation. Exclusion criteria were testicular volumes >10 ml and high bleeding or infection risk. There were 18 patients with a diagnosis of malignancy and 14 patients a non-malignant diagnosis. While 20 patients had the testicular biopsy performed 1-45 days after chemotherapy, 12 patients had not received any chemotherapy. In addition, 14 testicular tissue samples of patients with no reported testicular pathology, obtained from the internal biobank of the Department of Pathology at Karolinska University Hospital, were included as control samples in addition to reference values obtained from a recently published meta-analysis. The quantity of spermatogonia was assessed by both morphological and immunohistochemical analysis.
MAIN RESULTS AND THE ROLE OF CHANCE
The main finding was a significant reduction in spermatogonial cell counts in boys treated with alkylating agents or with hydroxyurea for sickle cell disease. The mean S/T values in boys exposed to alkylating agents (0.2 ± 0.3, n = 6) or in boys with sickle cell disease and exposed to hydroxyurea (0.3 ± 0.6, n = 6) were significantly lower (P = 0.003 and P = 0.008, respectively) than in a group exposed to non-alkylating agents or in biobank control samples (1.7 ± 1.0, n = 8 and 4.1 ± 4.6, n = 14, respectively). The mean S/T values of the testicular tissue samples included in the biobank control group and the patient group exposed to non-alkylating agents were within recently published normative reference values.
LIMITATIONS, REASONS FOR CAUTION
Normal testicular tissue samples included in this study were obtained from the internal biobank of Karolinska University Hospital. Samples were considered normal and included in the study if no testicular pathology was reported in the analysed samples. However, detailed information regarding previous medical treatments and testicular volumes of patients included in this biobank were not available.
WIDER IMPLICATIONS OF THE FINDINGS
This study summarizes, for the first time, spermatogonial quantity in a prepubertal patient cohort just before and after potentially sterilizing treatments. Boys facing cancer and cytotoxic therapies are regarded as the major group who will benefit from novel fertility preservation techniques. There are no previous reports correlating spermatogonial quantity to cumulative exposure to alkylating agents and anthracyclines (non-alkylating agents) and no information about the timing of cytotoxic exposures among this particular patient cohort. For prepubertal boys in whom fertility preservation is indicated, testicular tissue should be obtained before initiation of chemotherapy with alkylating agents, whilst for those with sickle cell disease and treated with hydroxyurea, this approach to fertility preservation may not be feasible.
STUDY FUNDING/COMPETING INTEREST(S)
This study was supported by grants from The Swedish Childhood Cancer Foundation (PR2016-0124; TJ2016-0093; PR2015-0073, TJ2015-0046) (J.-B.S. and K.J.), the Jane and Dan Olssons Foundation (2016-33) (J.-B.S.), the Finnish Cancer Society (K.J.), the Foundation for Paediatric Research (J.-B.S.), Kronprinsessan Lovisas Förening För Barnasjukvård/ Stiftelsen Axel Tielmans Minnesfond, Samariten Foundation (J.-B.S.), the Väre Foundation for Paediatric Cancer Research (K.J.) and the Swedish Research Council (2012-6352) (O.S.). R.T.M. was supported by a Wellcome Trust Fellowship (09822). J.P.A.-L. and M.K. were supported by the ITN Marie Curie program 'Growsperm' (EU-FP7-PEOPLE-2013-ITN 603568). The authors declare no conflicts of interest.
TRIAL REGISTRATION NUMBER
N/A.
The aim of this study was to analyze the prevalence of frailty and physical health limitations among long-term survivors of high-risk neuroblastoma (HR NBL) and to investigate whether frail health is ...associated with variables of cardiovascular function, markers of inflammation and telomere length. A national study cohort of 19 (median age 22, range 16-30 years) long-term (>10 years) HR NBL survivors was studied and the findings were compared with 20 age- and sex-matched controls. Frailty was defined as ⩾3 of the following conditions: low muscle mass, low energy expenditure, slow running and weakness. The prevalence of frailty was significantly higher among the HR NBL survivors 9/19 (47%) than among the controls (0%). Thirteen (68%) of the survivors reported significant physical health limitations in vigorous activities, as opposed to none of the controls. The HR NBL survivors had significantly shorter telomere length and higher serum levels of high sensitivity C-reactive protein than did the controls. Frail health and poor physical functioning are prevalent among HR NBL survivors and suggest premature aging. Survivors with gonadal damage, very low fat mass percentage, low glycosylated hemoglobin A1c and increased common carotid artery intima-media thickness may be more prone to early aging after high dose therapy.
Despite improvement of current treatment strategies and novel targeted drugs, relapse and treatment resistance largely determine the outcome for acute myeloid leukemia (AML) patients. To identify the ...underlying molecular characteristics, numerous studies have been aimed to decipher the genomic- and transcriptomic landscape of AML. Nevertheless, further molecular changes allowing malignant cells to escape treatment remain to be elucidated. Mass spectrometry is a powerful tool enabling detailed insights into proteomic changes that could explain AML relapse and resistance. Here, we investigated AML samples from 47 adult and 22 pediatric patients at serial time-points during disease progression using mass spectrometry-based in-depth proteomics. We show that the proteomic profile at relapse is enriched for mitochondrial ribosomal proteins and subunits of the respiratory chain complex, indicative of reprogrammed energy metabolism from diagnosis to relapse. Further, higher levels of granzymes and lower levels of the anti-inflammatory protein CR1/CD35 suggest an inflammatory signature promoting disease progression. Finally, through a proteogenomic approach, we detected novel peptides, which present a promising repertoire in the search for biomarkers and tumor-specific druggable targets. Altogether, this study highlights the importance of proteomic studies in holistic approaches to improve treatment and survival of AML patients.
The aim of the study was to evaluate long-term ovarian function after allogeneic hematopoietic stem cell transplantation (HSCT) in childhood and adolescence.
Predictive factors for ovarian function ...were evaluated among 92 adult or pubertal female survivors transplanted at Huddinge and Helsinki University Hospital during 1978-2000, at a mean age of 9±4.3 years (range 1-19). At the time of the study a mean±s.d. of 13±5.5 years (range 6-27) had elapsed since the HSCT and the mean age of the participants was 22±6.3 years (range 9-41).
Spontaneous puberty based on breast development occurred in 40 and menarche in 30 of the 70 girls who were prepubertal at transplantation. Six out of 20 girls who received HSCT after initiation of pubertal development recovered their ovarian function. Younger age at HSCT, conditioning without total body irradiation (TBI), and a non-leukemia diagnosis predicted the spontaneous menarche. The incidence of menarche was higher after fractioned vs single fraction TBI (P<0.05), cyclophosphamide (Cy) vs busulfan (Bu)-based conditioning (P<0.05), and among leukemia patients transplanted at first remission vs later remissions (P<0.01) and with no cranial irradiation (cranial radiotherapy, CRT) vs given CRT (14-24 Gy) (P<0.01). The majority of recipients conditioned with only Cy vs TBI (P<0.001) or vs Bu-based regimens (P<0.01) showed preserved ovarian function and required no estrogen replacement at their latest follow-up visit at a mean age of 23±6.3 years (range 15-41). Ten women became pregnant.
Patients conditioned with TBI or Bu-based regimes are at high risk of ovarian failure. Intensive anti-leukemia therapy before HSCT including CRT especially among relapsed patients may further decrease the possibility of spontaneous menarche.
The rhabdoid tumor (RT) predisposition syndromes 1 and 2 (RTPS1 and 2) are rare genetic conditions rendering young children vulnerable to an increased risk of RT, malignant neoplasms affecting the ...kidney, miscellaneous soft-part tissues, the liver and the central nervous system (Atypical Teratoid Rhabdoid Tumors, ATRT). Both, RTPS1&2 are due to pathogenic variants (PV) in genes encoding constituents of the BAF chromatin remodeling complex, i.e.
SMARCB1
(RTPS1) and
SMARCA4
(RTPS2). In contrast to other genetic disorders related to PVs in
SMARCB1
and
SMARCA4
such as Coffin-Siris Syndrome, RTPS1&2 are characterized by a predominance of truncating PVs, terminating transcription thus explaining a specific cancer risk. The penetrance of RTPS1 early in life is high and associated with a poor survival. However, few unaffected carriers may be encountered. Beyond RT, the tumor spectrum may be larger than initially suspected, and cancer surveillance offered to unaffected carriers (siblings or parents) and long-term survivors of RT is still a matter of discussion. RTPS2 exposes female carriers to an ill-defined risk of small cell carcinoma of the ovaries, hypercalcemic type (SCCOHT), which may appear in prepubertal females. RT surveillance protocols for these rare families have not been established. To address unresolved issues in the care of individuals with RTPS and to propose appropriate surveillance guidelines in childhood, the SIOPe Host Genome working group invited pediatric oncologists and geneticists to contribute to an expert meeting. The current manuscript summarizes conclusions of the panel discussion, including consented statements as well as non-evidence-based proposals for validation in the future.
Nowadays, allogeneic haematopoietic stem cell transplantation (allo-HSCT) is a well-established treatment procedure and often the only cure for many patients with malignant and non-malignant ...diseases. Decrease in short-term complications has substantially contributed to increased survival. Therefore long-term sequelae are reaching the focus of patient care. One of the most important risks of stem cell transplant survivors is infertility. As well as in the field of allo-HSCT also the field of reproductive medicine has achieved substantial advances to offer potential options for fertility preservation in both boys and girls. Access to these procedures as well as their financing differs significantly throughout Europe. As all European children and adolescents should have the same possibility, the Paediatric Diseases Working Party of the European Society for Blood and Marrow Transplantation organised an expert meeting in September 2015. This manuscript describes the recommendations for the diagnosis and pre-emptive procedures that should be offered to all children and adolescents in Europe who have to undergo an allo-HSCT.
High-dose therapy and hematopoietic stem cell transplantation (HSCT) have been shown to improve survival rates in high-risk neuroblastoma (HR-NBL), but may cause adverse effects on the growing ...skeleton. We studied skeletal health in a national cohort of long-term survivors of HR-NBL (n=21; age 16-30 years, median 22 years) and in 20 healthy age- and sex-matched controls. In addition to clinical evaluation and measurement of bone mineral density (BMD) by dual-energy X-ray absorptiometry, we performed spinal magnetic resonance imaging. Skeletal complications were categorized according to Common Terminology Criteria for Adverse Events (CTCAE). Altogether, 18/21 survivors presented with at least one skeletal adverse event according to CTCAE, the most common skeletal complications being short stature (n=14) and osteopenia (n=13). Altogether, 38% of the subjects had a severe complication (CTCAE score ⩾3) including bilateral slipped capital femoral epiphyseolysis in 3/21. Fracture rate was not increased. In spinal MRI, no vertebral fractures were found and degenerative intervertebral disc changes were equally prevalent in survivors and controls. BMD was lower in survivors than controls, but differences became non-significant when adjusted for bone size. In conclusion, skeletal late complications are common and can significantly impair the quality of life in young adult survivors of HR-NBL treated with high-dose protocols and HSCT.
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