Male Gonadal Function after Allogeneic Hematopoietic Stem Cell Transplantation in Childhood: A Cross-Sectional, Population-Based Study

Reproductive late effects and testosterone replacement therapy in male childhood cancer survivors: A population-based study (the Fex-Can study)

Childhood cancer survivors are at risk of various endocrine late effects affecting their quality of life. The aim of this study was to assess the prevalence and predictors of endocrine and reproductive outcomes in young adult survivors. A secondary aim was to assess possible associations between testosterone replacement therapy (TRT) and other endocrine, cardiovascular and psychosocial late effects. This nationwide study comprised 1212 male childhood cancer survivors aged 19-40 years, identified through the National Quality Registry for Childhood Cancer in Sweden. Median age at diagnosis during 1981-2017 was 7 (range 0-17) and at study 29 (19-40) years. The study combined self-report survey data with cancer treatment data from the national registry. Hormone-induced puberty was self-reported by 3.8% of the survivors and ongoing TRT by 6.0%. In separate logistic regression analyses, these treatments were associated with hematopoietic stem cell transplantation and cranial radiotherapy. Hormone-induced puberty was additionally associated with younger age at diagnosis. Men with TRT had a higher prevalence of other endocrine deficiencies, cholesterol medication, depressive symptoms and fatigue as well as a lower probability of living with a partner, having a biological child or current occupation. In the total male cohort, 28.2% reported having a biological child. Reassuring reproductive outcomes after less intensive therapies and low frequency of TRT were observed in young adult male childhood cancer survivors treated in the most recent treatment era. However, men with TRT suffered from several other endocrine, cardiovascular and psychosocial late effects, indicating a need for long-term monitoring of this high-risk group.

Effects of female bone marrow transplantation on male reproductive organs

Graft-versus-host disease (GVHD), an adverse effect after bone marrow transplantation (BMT), may affect male reproductive function. It is hypothesized that a sex-mismatched BMT induces GVHD in male reproductive organs because female immune cells are not immunologically tolerant to specific antigens of the male organs. However, this hypothesis has not been experimentally verified using male (M) recipient animals following BMT from the female (F) donors. Therefore, the aim of the present study is to examine whether the female BMT to males (F→M group) induces some GVHD reactions in the testis and the other male reproductive organs. The results showed that no inflammation was found in recipients of the male BMT to males (M→M group), whereas significant inflammatory cell responses lasting for at least 4 months were induced in testis, epididymis, prostate and preputial gland in some mice of F→M group. The most severe lesion was found in the preputial gland, in which lymphocytic inflammation was accompanied by loss of glandular acini, thickening of the interstitum and increased cytokines such as TNF-α and IFN-γ. Western blot analyses revealed that sera from the F→M group reacted with various antigens of the male reproductive organs. These results indicate that transplanted female immune cells may recognize the male reproductive organs as immunologically foreign ones and induce chronic GVHD, which may affect male reproductive function.

The relationship between hematologic malignancies on male hypogonadism: a scoping review

INTRODUCTION

The associated symptoms of hypogonadism have been reported in patients with various types of cancer. However, the prevalence and significance of hypogonadism among certain hematologic malignancies have not been completely summarized in recent literature.

OBJECTIVE

In this review we aimed to examine the current literature on hypogonadism in patients with hematologic malignancies, with emphasis on leukemias, lymphomas, and multiple myeloma (MM).

METHODS

This review included relevant studies published before July 2023 that were retrieved through a search of PubMed using the keywords "hematologic cancer," "hematologic malignancy," blood cancer," "leukemia," "lymphoma," "hypogonadism," "multiple myeloma," and "testosterone."

RESULTS

The search yielded 214 studies, of which 21 met the inclusion criteria. Commonly reported findings were that patients who had received hematopoietic stem cell therapy for acute lymphoblastic leukemia and acute myelogenous leukemia as children had laboratory-confirmed hypogonadism as adults. However, the impact of these diseases on hypogonadal symptoms was variable in these studies.Studies reporting on lymphoma and hypogonadism had mixed results, with some studies finding that the degree of cytotoxic chemotherapy was associated with hypogonadism, while others showed no correlation. Regardless, multiple studies found that hypogonadism secondary to lymphoma treatment and symptoms of hypogonadism had no apparent association.The most comprehensive assessment of the frequency of hypogonadism in an MM cohort found that 74% of 561 MM patients were classified as hypogonadal compared to 33% of patients in a control population. Testosterone supplementation was found to lower interleukin-6 levels, which could potentially help manage some of the adverse effects of MM, including decreased bone mineral density.

CONCLUSION

There is a relationship between hematologic malignancies and hypogonadism, which is likely multifactorial. In this review we established that the most plausible factors are related to the secondary effects of gonadotoxic treatments and/or systemic inflammatory responses to the diseases.

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.

Impact of low- or moderate-risk gonadotoxic chemotherapy prior to testicular tissue freezing on spermatogonia quantity in human (pre)pubertal testicular tissue

STUDY QUESTION

What is the impact of low- or moderate-risk gonadotoxic chemotherapy received prior to testicular tissue freezing (TTF), and of the cancer itself, on spermatogonia quantity in testicular tissue from (pre)pubertal boys?

SUMMARY ANSWER

Vincristine, when associated with alkylating agents, has an additional adverse effect on spermatogonia quantity, while carboplatin has no individual contribution to spermatogonia quantity, in testicular tissue of (pre)pubertal boys, when compared to patients who have received non-alkylating chemotherapy.

WHAT IS KNOWN ALREADY

The improved survival rates after cancer treatment necessitate the inclusion of fertility preservation procedures as part of the comprehensive care for patients, taking into consideration their age. Sperm cryopreservation is an established procedure in post-pubertal males while the TTF proposed for (pre)pubertal boys remains experimental. Several studies exploring testicular tissue of (pre)pubertal boys after TTF have examined the tubular fertility index (TFI, percentage of seminiferous tubule cross-sections containing spermatogonia) and the number of spermatogonia per seminiferous tubule cross-section (S/T). All studies have demonstrated that TFI and S/T always decrease after the introduction of chemotherapeutic agents, especially those which carry high gonadotoxic risks such as alkylating agents.

STUDY DESIGN, SIZE, DURATION

Testicular tissue samples from 79 (pre)pubertal boys diagnosed with cancer (from 6 months to 16 years of age) were cryopreserved between May 2009 and June 2014. Their medical diagnoses and previous chemotherapy exposures were recorded. We examined histological sections of (pre)pubertal testicular tissue to elucidate whether the chemotherapy or the primary diagnosis affects mainly TFI and S/T.

PARTICIPANTS/MATERIALS, SETTING, METHODS

(Pre)pubertal boys with cancer diagnosis who had been offered TTF prior to conditioning treatment for hematopoietic stem cell transplantation were included in the study. All the patients had previously received chemotherapy with low- or moderate-risk for future fertility. We have selected patients for whom the information on the chemotherapy received was complete. The quantity of spermatogonia and quality of testicular tissue were assessed by both morphological and immunohistochemical analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

A significant reduction in the number of spermatogonia was observed in boys treated with alkylating agents. The mean S/T values in boys exposed to alkylating agents were significantly lower compared to boys exposed to non-alkylating agents (P = 0.018). In contrast, no difference was observed for patients treated with carboplatin as the sole administered alkylating agent compared to the group of patients exposed to non-alkylating agents. We observed an increase of S/T with age in the group of patients who did not receive any alkylating agent and a decrease of S/T with age when patients received alkylating agents included in the cyclophosphamide equivalent dose (CED) formula (r = 0.6166, P = 0.0434; r = -0.3759, P = 0.0036, respectively). The TFI and S/T decreased further in the group of patients who received vincristine in combination with alkylating agents (decrease of 22.4%, P = 0.0049 and P < 0.0001, respectively), but in this group the CED was also increased significantly (P < 0.0001). Multivariate analysis, after CED adjustment, showed the persistence of a decrease in TFI correlated with vincristine administration (P = 0.02).

LIMITATIONS, REASONS FOR CAUTION

This is a descriptive study of testicular tissues obtained from (pre)pubertal boys who were at risk of infertility. The study population is quite heterogeneous, with a small number of patients in each sub-group. Our results are based on comparisons between patients receiving alkylating agents compared to patients receiving non-alkylating agents rather than chemotherapy-naive patients. The French national guidelines for fertility preservation in cancer patients recommend TTF before highly gonadotoxic treatment. Therefore, all the patients had received low- or moderate-risk gonadotoxic chemotherapy before TTF. Access to testicular tissue samples from chemotherapy-naive patients with comparable histological types of cancer was not possible. The functionality of spermatogonia and somatic cells could not be tested by transplantation or in vitro maturation due to limited sample sizes.

WIDER IMPLICATIONS OF THE FINDINGS

This study summarizes the spermatogonial quantity of (pre)pubertal boys prior to TTF. We confirmed a negative correlation between the cumulative exposure to alkylating agents and spermatogonial quantity. In addition, the synergistic use of vincristine in combination with alkylating agents showed a cumulative deleterious effect on the TFI. For patients for whom fertility preservation is indicated, TTF should be proposed for chemotherapy with a predicted CED above 4000 mg/m2. However, the data obtained from vincristine and carboplatin use should be confirmed in a subsequent study including more patients.

STUDY FUNDING/COMPETING INTEREST(S)

This study had financial support from a French national research grant PHRC No. 2008/071/HP obtained by the French Institute of Cancer and the French Healthcare Organization. The sponsors played no role in the study. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Male pediatric, adolescent, and young adult reproductive survivorship

As pediatric, adolescent, and young adult cancer survival rates increase, emphasis is placed on reducing late effects, including reproductive complications and potential impact to fertility. Male survivors are at risk of abnormalities in sperm, hormone deficiencies, and sexual dysfunction. This can impact one's progression into puberty and ability to have a biological child and impacts quality of life following treatment. Access to reproductive care is important and requires patient assessment and appropriate referral to reproductive specialists. This review addresses reproductive complications associated with therapy, standard-of-care testing, and therapeutic interventions. The psychologic impact on psychosexual functioning is also addressed.

Reduced-Intensity Conditioning Mitigates Risk for Primary Ovarian Insufficiency but Does Not Decrease Risk for Infertility in Pediatric and Young Adult Survivors of Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation (HSCT) is a curative therapy for many pediatric malignant and nonmalignant conditions. Gonadal insufficiency or infertility is present in almost all HSCT survivors who received a myeloablative conditioning (MAC) regimen. Reduced-intensity conditioning (RIC) regimens are being increasingly used in medically fragile patients or in patients with nonmalignant diagnoses to limit the toxicities associated with HSCT; however, the short-term and long-term gonadal toxicity of RIC regimens in pediatric and young adult survivors remains unknown. In this study, we compared the prevalence of gonadal insufficiency and infertility among pubertal and postpubertal pediatric and young adult survivors of HSCT who received a RIC regimen versus those who received a MAC regimen. Twenty-three females (RIC, n = 8; MAC, n = 15) and 35 males (RIC, n = 19; MAC, n = 16) were included in this single-center, retrospective cross-sectional study. Eligible patients were those with available laboratory results who were ≥1 year post-HSCT, age <40 years, and pubertal or postpubertal as assessed by an endocrinologist. Follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, and anti-Müllerian hormone (AMH) levels were measured in females, and FSH, LH, total testosterone, and inhibin B (InhB) levels were measured in males. Twenty-one males (RIC, n = 11; MAC, n = 10) underwent semen analysis through a separate consent. Parametric and nonparametric analyses were undertaken to compare the RIC and MAC groups. Female patients who received RIC were less likely than those who received MAC to develop primary ovarian insufficiency, as demonstrated by elevated FSH (P = .02) and low estradiol (P = .01) or elevated LH (P = .09). Most females in the RIC (75%) and MAC (93%) groups had low AMH levels, indicating low or absent ovarian reserve, with no significant difference between the groups (P = .53). In males, there were no significant differences between the 2 groups in the prevalence of abnormal FSH, LH, testosterone, or InhB levels. Ten of 11 RIC males (91%) and 10 of 10 MAC males (100%) had azoospermia or oligospermia, at a median time to semen analysis from HSCT of 3.7 years (range, 1.3 to 12.2 years). RIC may pose less risk than MAC for primary ovarian insufficiency among female survivors of HSCT; however, both female and male recipients of either RIC or MAC regimens are at high risk for infertility. In the largest reported series of semen analyses of pediatric and young adult male recipients of RIC, azoospermia or oligospermia was found in nearly all (91%) RIC survivors. All patients undergoing HSCT should receive counseling about the high risk of gonadal toxicity, and efforts should be made to preserve fertility in patients undergoing either RIC or MAC.

Metabolic Dysregulation in Adult Survivors of Pediatric Hematopoietic Stem Cell Transplantation: The Role of Incretins

CONTEXT

Survivors of pediatric hematopoietic stem cell transplantation (HSCT) have increased risk of developing metabolic syndrome (MetS), but the mechanisms are poorly understood.

OBJECTIVE

We aimed to test the hypothesis that insufficient secretion of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) plays a pathogenetic role in HSCT survivors with MetS.

METHODS

This cross-sectional cohort study, conducted at the Danish national referral center for HSCT, studied 42 male HSCT survivors (median age 28.9 years) for a median 21.2 years from HSCT, along with 15 age- and sex-matched healthy controls. Main outcome measures were glucose metabolism and incretin hormones (by oral glucose tolerance test [OGTT]) and MetS criteria. The hypothesis was formulated before data collection.

RESULTS

GLP-1, GIP, and glucagon during an OGTT were similar in patients and controls, with no overall difference between survivors with (24%) and without MetS. However, fasting glucagon was significantly higher in patients with hypertriglyceridemia (mean difference [MD]: 6.1 pmol/L; 95% CI, 1.5-10.8; P = 0.01), and correlated with HDL (MD: 4.7 mmol/L; 95% CI, -0.6 to 9.9; P = 0.08), android-gynoid ratio (correlation coefficient [r] = 0.6, P = 0.0001) and waist-hip ratio (r = 0.5, P = 0.002). A similar pattern was seen for GIP, correlating positively with triglyceride (MD: 60%; 95% CI, 44-82; P = 0.002). GIP levels were significantly increased in patients treated with total body irradiation (TBI) (MD: 165%; 95% CI, 118-230; P = 0.004), which was found to be a significant risk factor for MetS.

CONCLUSION

This study demonstrates an altered production of incretin hormones in HSCT survivors previously treated with TBI, developing dyslipidemia and abdominal adiposity.

Patient-reported long-term outcome following allogeneic hematopoietic stem cell transplantation in pediatric chronic myeloid leukemia

Background

Pediatric CML is very rare. Before the introduction of tyrosine kinase inhibitors (TKIs), allogeneic hematopoietic stem cell transplantation (HSCT) from a donor -if available- was the standard cure attempt. Data on the long-term outcome and health-related quality of life (HRQOL) in former pediatric CML patients undergoing HSCT are lacking.

Study question

We investigated long-term survivors' self-reporting to a questionnaire sent out to patients formerly enrolled in pediatric CML-HSCT trials.

Methods

Individuals with CML transplanted at age <18 years were identified from the German Childhood Cancer Registry database. Long-term survivors received a questionnaire based on the SF-36 and FACT-BMT asking them to self-report HRQOL issues. (Ethical vote #541_20 B, Medical Faculty, University of Erlangen-Nürnberg).

Results

111/171 (64.9%) individuals survived HSCT long-term and 86/111 (77.5%) fulfilled all inclusion criteria and received the questionnaire. 37/86 (43%) participants (24 female, 13 male, median age at HSCT 12 years [range 2-18], median age at the time of the survey 29 years [range 18-43]) responded after a median follow-up period of 19 years (range 4-27) after HSCT. 10/37 (27%) participants underwent no regular medical follow-up examinations. Self-reported symptoms like chronic graft-versus-host disease (cGvHD)-associated organ impairments and conditioning regimen consequences could causatively not sharply be separated in each case. Complains comprised hypothyroidism (N=11, 30%), infertility (N=9, 24%), lung problems, dry eyes (each N=7, 19%), skin alterations (N=6, 17%), hair problems (N=4, 11%), and sexual dysfunction (N=3, 9%). 10 (27%) participants experienced 13 CML relapses after a median interval from HSCT of 31 months (range 2-93). Only one patient underwent 2nd SCT after failure of relapse treatment with TKIs. Six secondary malignancies (dysplastic melanocytic nevus and ALL, basal cell carcinoma (N=2), rhabdomyosarcoma, and thyroid carcinoma developed in 5 (13%) participants. As assessed by the SF-36 questionnaire, impaired physical health was mainly associated with cGvHD. The mental component summary score showed that also participants without cGvHD scored significantly lower than the general population. When assessed by the FACT-BMT, participants with cGvHD scored significantly lower while participants without cGvHD scored even 5 points higher than the data from controls. 18 (49%) participants considered the sequelae of HSCT an obstacle to education. Out of the total cohort, N=20 (54%), N=7 (19%), N=5 (14%), and N=4 (11%) participants worked full time, part-time, were unemployed, or had not yet finalized their education, respectively. 20 (54%) participants lived as singles, 8 (22%) lived in a partnership, 6 (16%) were married, and 3 (8%) had been divorced. Four (11%) participants reported a total number of 7 children.

Conclusion

This first assessment of HRQOL in former pediatric patients with CML surviving HSCT for more than two decades demonstrates self-reported satisfactory well-being only in the absence of cGvHD. Research-based on self-reported outcomes sheds light on former patients' perspectives and provides an additional layer of valuable knowledge for pediatric and adult hematologists. Regular follow-up examinations are mandatory helping to avoid that late secondary neoplasias, CML-relapse, and disorders forming the broad range of possible long-term consequences of HSCT are not detected too late.

Physical Fitness and Frailty in Males after Allogeneic Hematopoietic Stem Cell Transplantation in Childhood: A Long-Term Follow-Up Study

Purpose and methods: To analyze physical fitness, physical activity and the prevalence of frailty in male long-term survivors of pediatric allogeneic hematopoietic stem cell transplantation (HSCT). We performed a Nordic two-center study of 98 male survivors (mean age 28.7 years, range 18.5–47.0) treated with pediatric allogeneic hematopoietic stem cell transplantation (HSCT) 1980–2010 in denmark or finland. physical fitness was evaluated by the dominant hand grip-strength, timed up-and-go, sit-to-stand, gait speed and two-minute walk tests. Results: Survivors presented significantly lower muscle strength and muscle endurance in the dominant hand-grip strength (median Z-score −0.7, range −4.3–3.9) and sit-to-stand tests (median Z-score −1.5, range −3.5–2.5) compared to age and sex matched normative values of the tests. However, mobility and gait speed were not affected on a group level. The prevalence of frailty (pre-frail 20% or frail 10%) was high among the survivors. In multiple regression analysis, chronic graft-versus-host disease, shorter stature, higher body fat mass and hazardous drinking predicted prefrail/frail status. Common cardiovascular risk factors, such as increased levels of serum triglycerides, higher resting heart rate and diastolic blood pressure, were associated with lower physical fitness. Conclusion: Low muscle strength and a high incidence of frailty were observed in survivors of pediatric HSCT. There is a predominant risk of cardiovascular and metabolic diseases in the long-term.

Male-specific late effects in adult hematopoietic cell transplantation recipients: a systematic review from the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research and Transplant Complications Working Party of the European Society of Blood and Marrow Transplantation

Male-specific late effects after hematopoietic cell transplantation (HCT) include genital chronic graft-versus-host disease (GvHD), hypogonadism, sexual dysfunction, infertility, and subsequent malignancies. They may be closely intertwined and cause prolonged morbidity and decreased quality of life after HCT. We provide a systematic review of male-specific late effects in a collaboration between transplant physicians, endocrinologists, urologists, dermatologists, and sexual health professionals through the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research, and the Transplant Complications Working Party of the European Society of Blood and Marrow Transplantation. The systematic review summarizes incidence, risk factors, screening, prevention and treatment of these complications and provides consensus evidence-based recommendations for clinical practice and future research.

Non-myeloablative conditioning is sufficient to achieve complete donor myeloid chimerism following matched sibling donor bone marrow transplant for myeloproliferative leukemia virus oncogene (MPL) mutation-driven congenital amegakaryocytic thrombocytopenia: Case report

BACKGROUND

Congenital amegakaryocytic thrombocytopenia (CAMT) is a rare platelet production disorder caused mainly by loss of function biallelic mutations in myeloproliferative leukemia virus oncogene (MPL), the gene encoding the thrombopoietin receptor (TPOR). Patients with MPL-mutant CAMT are not only at risk for life-threatening bleeding events, but many affected individuals will also ultimately develop bone marrow aplasia owing to the absence of thrombopoietin/TPOR signaling required for maintenance of hematopoietic stem cells. Curative allogeneic stem cell transplant for patients with CAMT has historically used myeloablative conditioning; however, given the inherent stem cell defect in MPL-mutant CAMT, a less intensive regimen may prove equally effective with reduced morbidity, particularly in patients with evolving aplasia.

METHODS

We report the case of a 2-year-old boy with MPL-mutant CAMT and bone marrow hypocellularity who underwent matched sibling donor bone marrow transplant (MSD-BMT) using a non-myeloablative regimen consisting of fludarabine, cyclophosphamide, and antithymocyte globulin (ATG).

RESULTS

The patient achieved rapid trilinear engraftment and resolution of thrombocytopenia. While initial myeloid donor chimerism was mixed (88% donor), due to the competitive advantage of donor hematopoietic cells, myeloid chimerism increased to 100% by 4 months post-transplant. Donor chimerism and blood counts remained stable through 1-year post-transplant.

CONCLUSION

This experience suggests that non-myeloablative conditioning is a suitable approach for patients with MPL-mutant CAMT undergoing MSD-BMT and is associated with reduced risks of conditioning-related toxicity compared to traditional myeloablative regimens.

Fertility Preservation for Prepubertal Patients at Risk of Infertility: Present Status and Future Perspectives

The increasing cure rate of cancer has led to a vast population of survivors having to face the late adverse effects of oncological treatments, with fertility impairment being one of the most sensitive issues for patients. Different options to preserve the fertility of adult patients are routinely used in clinical practice. However, fertility preservation strategies for prepubertal patients at risk of infertility are limited to the cryopreservation of immature gonadal tissue. In recent decades, many research efforts have been focused on the future use of cryopreserved gonadal tissue. This review discusses the common status of fertility preservation measures for pediatric patients undergoing gonadotoxic treatment, focusing especially on the challenges that remain to be solved in order to implement this fundamental service.

Male-specific late effects in adult hematopoietic cell transplantation recipients: a systematic review from the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research and Transplant Complications Working Party of the European Society of Blood and Marrow Transplantation

BACKGROUND

Male-specific late effects after hematopoietic cell transplantation (HCT) include genital chronic graft-versus-host disease (GvHD), hypogonadism, sexual dysfunction, infertility, and subsequent malignancies, such as prostate, penile, and testicular cancer. They may be closely intertwined and cause prolonged morbidity and decreased quality of life after HCT.

OBJECTIVE

Here, we provide a systematic review of male-specific late effects in a collaboration between transplant physicians, endocrinologists, urologists, dermatologists, and sexual health professionals through the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research, and the Transplant Complications Working Party of the European Society of Blood and Marrow Transplantation.

STUDY DESIGN

We utilized systematic review methodology to summarize incidence, risk factors, screening, prevention and treatment of these complications and provide consensus evidence-based recommendations for clinical practice and future research.

RESULTS

Most of the evidence regarding male GvHD is still based on limited data, precluding strong therapeutic recommendations. We therefore recommend to systematically screen for male genital GvHD regularly and report it to large registries to allow for a better understanding. Future research should also address treatment since little published evidence is available to date. Male-specific endocrine consequences of HCT include hypogonadism which may also affect bone health. Since the evidence is scarce, current recommendations for hormone substitution and/or bone health treatment are based on similar principles as for the general population. Following HCT, sexual health decreases and this topic should be addressed at regular intervals. Future studies should focus on interventional strategies to address sexual dysfunction. Infertility remains prevalent in patients having undergone myeloablative conditioning, which warrants offering sperm preservation in all HCT candidates. Most studies on fertility rely on descriptive registry analysis and surveys, hence the importance of reporting post-HCT conception data to large registries. Although the quality of evidence is low, the development of cancer in male genital organs does not seem more prevalent than in the general population; however, subsequent malignancies in general seem to be more prevalent in males than females, and special attention should be given to skin and oral mucosa.

CONCLUSION

Male-specific late effects, probably more under-reported than female-specific complications, should be systematically considered during the regular follow-up visits of male survivors who have undergone HCT. Care of patients with male-specific late effects warrants close collaboration between transplant physicians and specialists from other involved disciplines. Future research should be directed towards better data collection on male-specific late effects and on studies about the interrelationship between these late effects, to allow the development of evidence based effective management practices.

Childhood reproductive hormone levels after pediatric hematopoietic stem cell transplantation in relation to adult testicular function

OBJECTIVES

Longitudinal assessment of testicular function after pediatric hematopoietic stem cell transplantation (HSCT) is needed to guide clinical follow-up. We investigated dynamics in male reproductive hormones after pediatric HSCT, focusing on pubertal timing and associations with testosterone deficiency and azoospermia in adulthood.

METHODS

This retrospective, longitudinal study included 39 survivors median 19 years after pediatric HSCT. Serum concentrations of LH, testosterone, FSH, and inhibin B from the time of HSCT, during puberty, and into adulthood were analyzed. Pubertal timing (rise in LH and testosterone) was compared to a reference cohort of 112 healthy boys. Associations between reproductive hormone levels during puberty and adult testicular function (including semen quality) were investigated.

RESULTS

Pubertal induction with testosterone was needed in 6/26 patients who were prepubertal at HSCT. In the remaining patients, pubertal timing was comparable to the reference cohort. However, 9/33 patients (without pubertal induction) developed testosterone deficiency in early adulthood, which was associated with higher LH levels from age 14 to 16 years. Azoospermia in adulthood was found in 18/26 patients without testosterone substitution. Higher FSH and lower inhibin B levels from mid-pubertal age were associated with azoospermia in adulthood, in patients being prepubertal at HSCT.

CONCLUSION

Our results indicate a substantial risk of deterioration in testicular function after pediatric HSCT, despite normal pubertal timing. Although reproductive hormone levels from mid-puberty indicated adult testicular function, prolonged follow-up into adulthood is needed in these patients, including clinical examination, reproductive hormone analysis, and semen sample for patients interested in their fertility potential.

Cardiorespiratory fitness and physical performance after childhood hematopoietic stem cell transplantation: a systematic review and meta-analysis

The effects of childhood hematopoietic stem cell transplantation (HSCT) on key organs can impair cardiorespiratory fitness, muscle strength, and physical performance. We aimed to provide an overview of childhood HSCT survivors' status on these parameters compared with healthy controls and discuss current insights into clinical risk factors. We performed a systematic search in six scientific databases, including studies published before April 2019 and performed a meta-analysis on cardiorespiratory fitness. Muscle strength and physical performance status were presented narratively. We included ten studies embodying 517 childhood HSCT survivors (mean 17.8 years at follow-up). The meta-analysis (n = 4 studies) showed that childhood HSCT survivors have lower cardiorespiratory fitness compared with healthy controls (Standard mean difference (SMD) -1.32 [95% CI -1-58 to -1.07]; I² 2%, p < 0.00001). Collectively, the studies indicated that childhood HSCT survivors have lower muscle strength (n = 4 studies) and physical performance (n = 3 studies) compared with healthy controls. Childhood HSCT survivors have impaired cardiorespiratory fitness years after ended treatment. Muscle strength and physical performance seem to be impaired, although these measures are insufficiently investigated. Associations between HSCT-specific clinical risk factors and cardiorespiratory fitness, muscle strength, and physical performance are required.

Metabolic Syndrome in Male Survivors of Pediatric Allogeneic Hematopoietic Stem Cell Transplantation: Impact of Total Body Irradiation, Low-Grade Inflammation, and Hypogonadism

Metabolic syndrome (MetS) is a growing concern in survivors of pediatric hematopoietic stem cell transplantation (HSCT), but little is known about the underlying mechanisms. This study aimed to determine the prevalence and clinical presentation of MetS in male long-term survivors of pediatric HSCT and to investigate predisposing factors, including low-grade inflammation, altered fat distribution, and low testosterone levels. We included 98 survivors age 19 to 47 years at a median follow-up of 18 years (range, 8 to 35 years) after pediatric HSCT. MetS was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria. The prevalence and clinical manifestations of MetS were compared between our cohort and a control group of males from the background population (n = 4767). Fat distribution was assessed by android/gynoid ratio from a whole-body dual-energy X-ray absorptiometry scan. Systemic inflammation was evaluated by IL-6 and high-sensitivity C-reactive protein (hsCRP). Serum testosterone levels were measured in morning samples. The prevalence of MetS was 30%, corresponding to the prevalence in the 50- to 80-year-old males from the background population. In individuals with MetS, hyperglycemia was more frequent in the HSCT survivors compared with age-matched controls with MetS (76% versus 20%; P < .001), whereas hypertension was more dominant in the control group with MetS (69% versus 93%; P = .01). In addition, normal or low body mass index was more commonly observed among HSCT survivors with MetS compared with age-matched controls with MetS (41% versus 11%; P = .002). MetS was more often associated with total body irradiation (TBI) compared with chemotherapy regimens (odds ratio [OR], 4.3; 95% confidence interval [CI], 1.2 to 24.4; P = .02), lower testosterone levels (OR, 5.4; 95% CI, 1.3 to 23.6; P = .02), higher IL-6 levels (OR, 1.8; 95% CI, 1.2 to 2.8; P = .004), and higher hsCRP levels (OR, 1.8; 95% CI, 1.3 to 2.6; P < .001) (estimates per 2-fold increase). In addition, an increased android/gynoid (AG) fat ratio was strongly associated with MetS (OR, 2.1; 95% CI, 1.5 to 2.9; P < .001), even though only 7% of patients met the criteria for increased abdominal circumference. Our results indicate an increased risk of MetS in early adulthood after pediatric HSCT. The clinical manifestations differed from those seen in age-matched controls with MetS, indicating different pathophysiology driven by hyperglycemia, altered fat distribution (despite no clinical abdominal obesity), and low-grade inflammation. Risk factors included TBI-based conditioning and low testosterone levels. These results underline the importance of continuous clinical assessment of the cardiometabolic risk profile and stress the presence of important dissimilarities in the pathophysiology of MetS in HSCT survivors compared with the background population.

Long-term follow-up of boys who have undergone a testicular biopsy for fertility preservation

STUDY QUESTION

What is the long-term reproductive health outcome of patients who have undergone testicular sampling for fertility preservation (FP) before and during the pubertal transition period?

SUMMARY ANSWER

In long-term follow-up after testicular sampling for FP, hormonal data showed that 33% of patients had primary seminiferous tubule insufficiency (high FSH) while semen analyses showed 52% of patients having a severe reduction in total sperm counts or complete absence of ejaculated sperm.

WHAT IS KNOWN ALREADY

During childhood and adolescence, both treatments for cancer and benign haematological diseases that require a bone marrow transplantation, can be detrimental to spermatogenesis by depleting the spermatogonial stem cell population. A testicular biopsy prior to chemotherapy or radiotherapy, even though still an experimental procedure, is now recommended for FP by European and USA oncofertility societies if performed within an institutional research setting. While short-term follow-up studies showed little to no post-operative complications and a normal testicular development after 1 year, data regarding the long-term follow-up of boys who have undergone this procedure are still lacking.

STUDY DESIGN, SIZE, DURATION

This is a longitudinal retrospective cohort study that reports on the long-term follow-up of pre- and peri-pubertal boys who have undergone a testicular biopsy for FP between May 2005 and May 2020. All the patients included in this study were referred to our programme by haematologists-oncologists who are part of a regional multi-centric collaborative care pathway.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Of the 151 boys referred to our FP programme, 139 parents/legal guardians accepted that their child undergo a testicular biopsy. Patient characteristics (i.e. age at biopsy, urogenital history, pubertal status at diagnosis), indications (disease type and dosage of gonadotoxic treatments), operative and post-operative data (biopsy volume, surgical complications), anatomopathological analyses (presence/absence of spermatogonia, Johnsen score) and reproductive data (semen analyses, FSH, LH, testosterone levels) were collected from the institutions' FP database and medical records or from the 'Brussels Health Network'. Cumulative alkylating agent treatment was quantified using the cyclophosphamide equivalent dose (CED). Patients who were 14 years or older at the time of the follow-up and in whom the testicular tissue was shown to contain spermatogonia were included in the reproductive outcome analysis. Comparison of the sperm count findings (absence/presence of spermatozoa) and FSH levels (high (≥10 IU/l)/normal) between patients who were either pre- (Tanner 1) or peri-pubertal (Tanner >1) at the time of the biopsy was done using the Mann-Whitney U or Fisher's tests. A multiple logistic regression was used to study the relationship between the hormone reproductive outcome (high versus normal FSH), as a proxy marker for fertility, and both the pubertal status (Tanner 1 versus Tanner >1) and Johnsen score at the time of the biopsy, while adjusting for CED.

MAIN RESULTS AND THE ROLE OF CHANCE

A testicular biopsy was performed in 139 patients either before (129/139) or after (10/139) the start of a gonadotoxic treatment. Post-operative complications occurred in 2.1% (3/139). At the time of the procedure, 88% (122/139) of patients were pre-pubertal and 12% (17/139) were peri-pubertal. The presence of spermatogonia was documented in 92% (128/139) of cases. Follow-up data were available for 114 patients after excluding 23 deceased and two patients lost to follow-up. A paediatric endocrinologist's follow-up including clinical examination and data on reproductive hormones was available for 57 patients (age ≥14) and 19 (33%) of these were found to have high FSH levels (20 ± 8.8 IU/l). There were 37 patients who had returned to the reproductive specialist's consultation for post-treatment fertility counselling and results on semen analysis were available in 27 of these cases; 14/27 (52%) had severely impaired semen parameters including 8 who were azoospermic. Among patients who received an alkylating agent-based treatment (n = 42), a peri-pubertal status (Tanner >1) at the time of diagnosis/biopsy was found to be associated with a higher risk of having primary testicular failure (defined by an FSH ≥ 10 IU/l) after treatment completion with an OR of 6.4 (95% CI 1.22-33.9; P = 0.03). Of all the patients, 2.6% had already fulfilled their wish to build a family or were actively seeking parenthood.

LIMITATIONS, REASONS FOR CAUTION

Although this is the largest cohort with follow-up data providing proxy markers of the reproductive potential of boys in whom a testicular biopsy for FP was performed before puberty or during the pubertal transition period, the amount of data provided is limited, and originating from a single programme. Further data collection to confirm the observations in other settings is therefore awaited.

WIDER IMPLICATIONS OF THE FINDINGS

Testicular sampling for FP should be offered to boys at risk of losing their fertility (and is recommended for those at high risk) as part of ethically approved research programmes. Long-term follow-up data on increasing numbers of boys who have undergone an FP procedure will help improve patient care in the future as patient-specific factors (e.g. urogenital history, age at gonadotoxic therapy) appear to influence their reproductive potential after gonadotoxic therapies.

STUDY FUNDING/COMPETING INTEREST(S)

FNRS-Télévie, the Salus Sanguinis Foundation and the Belgian Foundation against Cancer supported the studies required to launch the FP programme. The authors declare that they have no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

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.

Male Sexual Function after Allogeneic Hematopoietic Stem Cell Transplantation in Childhood: A Multicenter Study

There are many known endocrine complications after allogeneic hematopoietic stem cell transplantation (HSCT) in childhood including increased risk of biochemical hypogonadism. However, little is known about sexuality in adulthood following childhood HSCT. In this multicenter study, sexual functions and possible risk factors were assessed comprehensively in two national cohorts (Finland and Denmark) of male adult survivors of childhood HSCT. Compared to a healthy control group (n = 56), HSCT survivors (n = 97) reported less sexual fantasies, poorer orgasms, lower sexual activity with a partner and reduced satisfaction with their sex life, even in the presence of normal erectile functions and a similar frequency of autoerotic acts. Of the HSCT survivors, 35% were cohabitating/married and 66% were sexually active. Risk factors for poorer self-reported sexual functions were partner status (not cohabitating with a partner), depressive symptoms, CNS and testicular irradiation. Sexual dysfunction increased by age in the HSCT group with a pace comparable to that of the control group. However, because of the lower baseline level of sexual functions in the HSCT group, they will reach the level of clinically significant dysfunction at a younger age. Hence, male survivors of childhood HSCT should be interviewed in detail about their sexual health beyond erectile functions.