Progress in the development of childhood cancer therapy

Alkylating agents-induced gonadotoxicity in prepubertal males: Insights on the clinical and preclinical front

Rising cure rates in pediatric cancer patients warrants an increased attention toward the long-term consequences of the diagnosis and treatment in survivors. Chemotherapeutic agents can be gonadotoxic, rendering them at risk for infertility post-survival. While semen cryopreservation is an option that can be provided for most (post)pubertal boys before treatment, this is unfortunately not an option prepubertal in age, simply due to the lack of spermatogenesis. Over the last couple of years, studies have thus focused on better understanding the testis niche in response to various chemotherapeutic agents that are commonly administered and their direct and indirect impact on the germ cell populations. These are generally compounds that have a high risk of infertility and have been classified into risk categories in curated fertility guidelines. However, with it comes the lack of evidence and the challenge of using informative models and conditions most reflective of the physiological scenario, in short, the appropriate study designs for clinically relevant outcomes. Besides, the exact mechanism(s) of action for many of these "risk" compounds as well as other agents is unclear. Understanding their behavior and effect on the testis niche will pave the way for incorporating new strategies to ultimately combat infertility. Of the various drug classes, alkylating agents pose the highest risk of gonadotoxicity as per previously established studies as well as risk stratification guidelines. Therefore, this review will summarize the findings in the field of male fertility concerning gonadotoxicity of akylating agents as a result of chemotherapy exposure.

Post-treatment sperm cryopreservation practices in childhood and young adult cancer survivors

RESEARCH QUESTION

What are current practices of post-treatment fertility preservation in male childhood cancer survivors (CCS) who have not benefitted from pre-therapeutic fertility preservation in France and other European countries?

DESIGN

A survey was conducted of all fertility preservation centres in France (n = 30) and European fertility specialists (n = 9) in five European countries. Eight clinical cases and 40 questions were included to assess the effect of age at diagnosis, type of treatment (alkylating-agents, orchidectomy, testicular radiotherapy) and sperm parameters on the probability of a post-treatment fertility preservation proposal. Demographic characteristics of the responding practitioner were also collected.

RESULTS

Post-treatment sperm cryopreservation was proposed by 100% of fertility specialists in cases of severe oligoasthenoteratozoospermia, 77-88% in cases of moderate oligoasthenoteratozoospermia and in 65-77% in cases of sperm motility and vitality impairment. In cases of normal sperm parameters, 27-54% of fertility specialists would propose post-treatment sperm cryopreservation. These results did not differ significantly according to the type of treatment received or to responder-related factors. Practices of European specialists were also guided by sperm parameter results; 44-67% of specialists responding that they would propose sperm cryopreservation in cases of moderate to severe sperm parameter alterations.

CONCLUSION

Post-treatment semen analysis could be widely proposed to CCS who have not benefitted from pre-therapeutic fertility preservation. Post-treatment fertility preservation could be proposed in cases of persistent moderate to severe sperm parameter alterations. Guidelines would be important to homogenize practices and to encourage oncologists to refer CCS for fertility assessments.

The impact of vincristine on testicular development and function in childhood cancer

BACKGROUND

Increasing childhood cancer survival rates in recent decades have led to an increased focus on fertility as a long-term complication of cancer treatment. Male childhood cancer survivors often face compromised testicular function as a late effect of chemotherapy exposure, with no well-established options to prevent such damage and subsequent infertility. Despite vincristine being considered to be associated with low-gonadotoxic potential, in prepubertal rodents, it was recently shown to result in morphological alterations of the testis and in severely impaired fertility.

OBJECTIVE AND RATIONALE

This systematic review aimed to evaluate the effects of vincristine-containing regimens on human prepubertal testis with reference to testicular function and fertility in adulthood.

SEARCH METHODS

The systematic search of the literature was conducted according to PRISMA guidelines, and the study was registered with PROSPERO. PubMed and Scopus were searched for articles published in English between 01 January 1900 and 05 March 2021, with the search including 'chemotherapy', 'vincristine', 'prepubertal', 'testis', 'spermatogenesis' and related terms. Abstracts and full-text articles were screened and selected for, providing they met the inclusion criteria (≤12 years at treatment, exposure to vincristine-containing regimens and long-term fertility outcomes). Additional studies were identified via bibliography screening. Bias evaluation across included studies was conducted using the ROBINS-I tool, subdivided into assessment for confounding, participant selection, intervention classification, missing data, outcome measurements and selection of reported results.

OUTCOMES

Our initial search identified 288 articles of which 24 (8%; n = 7134 males) met all inclusion criteria. Control groups were included for 9/24 (38%) studies and 4/24 (17%) studies provided sub-analysis of the relative gonadotoxicity of vincristine-based agents. Primary outcome measures were: fertility and parenthood; semen analysis (World Health Organization criteria); and hormonal function and testicular volume. For the studies that performed vincristine sub-analysis, none reported negative associations with vincristine for the potential of siring a pregnancy, including the largest (n = 6224; hazard ratio = 0.56) controlled study. For semen analysis, no significant difference versus healthy controls was illustrated for mitotic inhibitors (including vincristine) following sub-analysis in one study (n = 143). For hormone analysis, a single study did not find significant impacts on spermatogenesis attributed to vincristine based on levels of FSH and semen analysis, which meant that its administration was unlikely to be responsible for the diminished testicular reserve; however, most of the studies were based on low numbers of patients receiving vincristine-containing chemotherapy. Analysis of bias demonstrated that studies which included vincristine exposure sub-analysis had a lower risk of bias when compared with cohorts which did not.

WIDER IMPLICATIONS

In contrast to recent findings in rodent studies, the limited number of clinical studies do not indicate gonadotoxic effects of vincristine following prepubertal exposure. However, given the relative lack of data from studies with vincristine sub-analysis, experimental studies involving vincristine exposure using human testicular tissues are warranted. Results from such studies could better inform paediatric cancer patients about their future fertility and eligibility for fertility preservation before initiation of treatment.

GnRH Antagonist Improves Pubertal Cyclophosphamide-Induced Long-Term Testicular Injury in Adult Rats

BACKGROUND

Gonadal injury following chemotherapy is of increasing importance with the continuous improvement of survival rates. The protection of gonadotropin hormone antagonist (GnRHant) in long-term adult survivors of adolescent cancers and some autoimmune diseases has not yet been evaluated.

METHODS

The present study was aimed at longitudinally exploring whether the GnRHant could alleviate testicular damage induced by cyclophosphamide (CPA) in a rat model. Pubertal male rats were assigned to receive CPA with and without GnRHant. CPA was administrated at a single dose (100 mg/kg). GnRHant was started one hour prior to CPA injection and continued for four weeks (0.1 mg/kg, 3 times a week). Body and testes weights, testicular hormones, histological changes, and expression of androgen receptor (AR) in the testis were analyzed when rats matured into adulthood and completed a round of spermatogenesis.

RESULTS

Our results showed that body weight, histological injury, and AR expression in the testis were improved in the GnRHant + CPA group. However, testes weight and testicular hormones (anti-Müllerian hormone, inhibin B, and testosterone) did not markedly change.

CONCLUSION

Our results indicate that the GnRHant administration before and after CPA in pubertal rats can protect long-term testicular injury induced by CPA via increased AR expression in the testes.

[Transgenerational impact of chemotherapy: Would the father exposure impact the health of future progeny?]

The number of cancer survivors is increasing and their quality of life is becoming a major public health issue. Cancer treatments reduce men's reproductive health by targeting spermatogenesis. Ultimately, DNA, chromatin and the epigenome of spermatozoa can be altered in cancer survivors. Knowing whether the history of cancer and the treatments received can have consequences on the health of their offspring is therefore a fundamental question for these patients. This review gathers the experimental and epidemiological evidences of the effects observed on the direct descendants and on several generations, and draws up the state of knowledge on the mechanisms potentially involved. Experimental data describe inter- and transgenerational effects of paternal exposure depending on the type of treatment, dose and time of exposure. In the human population, the analysis of the effects specifically due to chemotherapy is still limited because they are often combined with irradiation treatments. However, it appears that chemotherapy agents affect the birth rate but do not have a significant impact on the health of the children born. Nevertheless, the demonstration of modifications of the sperm epigenome in cancer survivors, even after a period of remission, as well as changes in the sperm of the progeny in animal models, suggests a possible transgenerational transmission that remains to be studied in the human population.

Pregnancy after chemotherapy in male and female survivors of childhood cancer treated between 1970 and 1999: a report from the Childhood Cancer Survivor Study cohort

BACKGROUND

The effect of many contemporary chemotherapeutic drugs on pregnancy and livebirth is not well established. We aimed to establish the effects of these drugs on pregnancy in male and female survivors of childhood cancer not exposed to pelvic or cranial radiotherapy.

METHODS

We used data from a subset of the Childhood Cancer Survivor Study cohort, which followed 5-year survivors of the most common types of childhood cancer who were diagnosed before age 21 years and treated at 27 institutions in the USA and Canada between 1970 and 1999. We extracted doses of 14 alkylating and similar DNA interstrand crosslinking drugs from medical records. We used sex-specific Cox models to establish the independent effects of each drug and the cumulative cyclophosphamide equivalent dose of all drugs in relation to pregnancies and livebirths occurring between ages 15 years and 44 years. We included siblings of survivors as a comparison group.

FINDINGS

We included 10 938 survivors and 3949 siblings. After a median follow-up of 8 years (IQR 4-12) from cohort entry or at age 15 years, whichever was later, 4149 (38%) survivors reported having or siring a pregnancy, of whom 3453 (83%) individuals reported at least one livebirth. After a median follow-up of 10 years (IQR 6-15), 2445 (62%) siblings reported having or siring a pregnancy, of whom 2201 (90%) individuals reported at least one livebirth. In multivariable analysis, survivors had a decreased likelihood of siring or having a pregnancy versus siblings (male survivors: hazard ratio [HR] 0·63, 95% CI 0·58-0·68; p<0·0001; female survivors: 0·87, 0·81-0·94; p<0·0001) or of having a livebirth (male survivors: 0·63, 0·58-0·69; p<0·0001; female survivors: 0·82, 0·76-0·89; p<0·0001). In male survivors, reduced likelihood of pregnancy was associated with upper tertile doses of cyclophosphamide (HR 0·60, 95% CI 0·51-0·71; p<0·0001), ifosfamide (0·42, 0·23-0·79; p=0·0069), procarbazine (0·30, 0·20-0·46; p<0·0001) and cisplatin (0·56, 0·39-0·82; p=0·0023). Cyclophosphamide equivalent dose in male survivors was significantly associated with a decreased likelihood of siring a pregnancy (per 5000 mg/m(2) increments: HR 0·82, 95% CI 0·79-0·86; p<0·0001). However, in female survivors, only busulfan (<450 mg/m(2) HR 0·22, 95% CI 0·06-0·79; p=0·020; ≥450 mg/m(2) 0·14, 0·03-0·55; p=0·0051) and doses of lomustine equal to or greater than 411 mg/m(2) (0·41, 0·17-0·98; p=0·046) were significantly associated with reduced pregnancy; cyclophosphamide equivalent dose was associated with risk only at the highest doses in analyses categorised by quartile (upper quartile vs no exposure: HR 0·85, 95% CI 0·74-0·98; p=0·023). Results for livebirth were similar to those for pregnancy.

INTERPRETATION

Greater doses of contemporary alkylating drugs and cisplatin were associated with a decreased likelihood of siring a pregnancy in male survivors of childhood cancer. However, our findings should provide reassurance to most female survivors treated with chemotherapy without radiotherapy to the pelvis or brain, given that chemotherapy-specific effects on pregnancy were generally few. Nevertheless, consideration of fertility preservation before cancer treatment remains important to maximise the reproductive potential of all adolescents newly diagnosed with cancer.

FUNDING

National Cancer Institute, National Institutes of Health, and the American Lebanese-Syrian Associated Charities.

Protective effect of Satureja montana extract on cyclophosphamide-induced testicular injury in rats

The present study investigated the protective effect of Satureja montana extract against cyclophosphamide-induced testicular injury in rats. Total phenolic and flavonoid contents of the extract were 1.03% and 0.34%w/w of dry herb expressed as chlorogenic acid and quercetin, respectively. HPLC analysis identified caffeic, syringic and rosmarinic acids as the chief phenolic acids, and rutin as the major flavonoid in the extract. Oral daily administration of S.montana extract (50mg/kg/day) for 7days before and 7days after an intraperitoneal injection of cyclophosphamide (200mg/kg) restored the reduced relative testicular weight, serum testosterone level and testicular alkaline phosphatase activity, raised the lowered testicular sorbitol dehydrogenase and acid phosphatase activities, and decreased the elevated testicular hemoglobin absorbance. It also attenuated lipid peroxidation, restored the lowered glutathione content, glucose-6-phosphate dehydrogenase, glutathione peroxidase and glutathione reductase activities, and improved total antioxidant capacity. Moreover, S.montana extract mitigated testicular DNA fragmentation, decreased the elevated Fas and Bax gene expression, up-regulated the decreased Bcl-2 and peroxisome proliferator-activated receptor-gamma (PPAR-γ) gene expression and normalized Akt1 protein level. Histopathological investigation confirmed the protective effects of the extract. Conclusively, S.montana extract protects the rat testis against cyclophosphamide-induced damage via anti-oxidative and anti-apoptotic mechanisms that seem to be mediated, at least in part, by PPAR-γ and Akt1 up-regulation.

Cumulative alkylating agent exposure and semen parameters in adult survivors of childhood cancer: a report from the St Jude Lifetime Cohort Study

BACKGROUND

Few data define the dose-specific relation between alkylating agent exposure and semen variables in adult survivors of childhood cancer. We undertook this study to test the hypothesis that increased exposure to alkylating agents would be associated with decreased sperm concentration in a cohort of adult male survivors of childhood cancer who were not exposed to radiation therapy for their childhood cancer.

METHODS

We did semen analysis on 214 adult male survivors of childhood cancer (median age 7·7 years [range 0·01-20·3] at diagnosis, 29·0 years [18·4-56·1] at assessment, and a median of 21·0 years [10·5-41·6] since diagnosis) who had received alkylating agent chemotherapy but no radiation therapy. Alkylating agent exposure was estimated using the cyclophosphamide equivalent dose (CED). Odds ratios (ORs) and 95% CIs for oligospermia (sperm concentration >0 and <15 million per mL) and azoospermia were calculated with logistic regression modelling.

FINDINGS

Azoospermia was noted in 53 (25%) of 214 participants, oligospermia in 59 (28%), and normospermia (sperm concentration ≥15 million per mL) in 102 (48%) participants. 31 (89%) of 35 participants who received CED less than 4000 mg/m(2) were normospermic. CED was negatively correlated with sperm concentration (correlation coefficient=-0·37, p<0·0001). Mean CED was 10 830 mg/m(2) (SD 7274) in patients with azoospermia, 8480 mg/m(2) (4264) in patients with oligospermia, and 6626 mg/m(2) (3576) in patients with normospermia. In multivariable analysis, CED was significantly associated with an increased risk per 1000 mg/m(2) CED for azoospermia (OR 1·22, 95% CI 1·11-1·34), and for oligospermia (1·14, 1·04-1·25), but age at diagnosis and age at assessment were not.

INTERPRETATION

Impaired spermatogenesis was unlikely when the CED was less than 4000 mg/m(2). Although sperm concentration decreases with increasing CED, there was substantial overlap of CED associated with normospermia, oligospermia, and azoospermia. These data can inform pretreatment patient counselling and use of fertility preservation services.

FUNDING

US National Cancer Institute, American Lebanese Syrian Associated Charities.

Influence of tumor necrosis factor α inhibitors on testicular function and semen in spondyloarthritis patients

OBJECTIVE

To evaluate sperm parameters and sexual hormones in young males affected with spondyloarthritis (SpA) before and after 1 year of anti-tumor necrosis factor (TNF) α treatment.

DESIGN

Prospective case-control study.

SETTING

Rheumatology and human reproduction pathology units at a university hospital.

PATIENTS

Ten SpA outpatients attending the rheumatology clinic; 20 healthy control subjects attending the unit of human reproduction pathology within an infertility prevention program.

INTERVENTIONS

At baseline and after a 12-month treatment, disease activity was assessed and an andrologic evaluation made.

MAIN OUTCOME MEASURE(S)

Rheumatologists assessed anamnestic, clinical, functional, and biomarker data. Andrologists evaluated semen analysis, fluorescence in situ hybridization for chromosomes X, Y, 13, 18, and 21, FSH, LH, and T plasma levels, and testicular color Doppler ultrasound.

RESULTS

At baseline, SpA patients showed reduced sperm motility, higher plasma LH and FSH, and lower T levels compared with control subjects; a significant correlation between disease activity and sperm quality was found. After treatment, a statistically significant decrease in sperm aneuploidies and normal hormone levels were observed.

CONCLUSIONS

Although inflammation in SpA appears to be related to impaired testicular function, anti-TNF-α agents seem to be safe on testicular function and fertility.

Astragalus membranaceus ameliorates reproductive toxicity induced by cyclophosphamide in male mice

The root of Astragalus membranaceus B(UNGE) (AM) is a medicinal herb that has been capable of reducing the adverse effects of conventional chemotherapy. To investigate the effects of AM on cyclophosphamide (CP)-induced reproductive toxicity in mouse testes, 5-week-old male imprinting control region mice were divided into five groups; CP was treated on the first day of each week for 5 weeks (100 mg/kg, i.p.), and AM was treated for 5 days a week for 5 weeks. At the end of the treatment period, the testes were taken out, cleared of the adhering tissues, and weighed. Epididymis was taken out and used for sperm analysis. Testis samples were frozen for real-time quantitative PCR and Western blot analysis. AM treatment increased diminished relative testes weight, and sperm count and motility in mice treated with CP. CP treatment has detrimental effects on the expression of cAMP-responsive element modulator (CREM), a transcription factor that is highly expressed in male germ cells and is crucial to post-meiotic germ cell differentiation. AM restored CREM at both the mRNA and protein levels. AM has beneficial influences and appears able to ameliorate relative testes weight, sperm parameters, and CREM expression against CP-induced reproductive toxicity.

Effect of fenugreek seeds extract on cyclophosphamide-induced histomorphometrical, ultrastructural and biochemical changes in testes of albino mice

Cyclophosphamide (CPA) is an anticancer drug used in the treatment of a variety of neoplastic lesions. On the other hand, treatment with CPA was accompanied by different toxic effects on different body organs. The present work was conducted to study the effect of fenugreek seed extract on histomorphometrical and ultrastructural changes induced by CPA in testes of albino mice. Twenty animals were given CPA (7.0 mg/kg body weight) three times/week orally for 8 weeks and were killed after 4 and 8 weeks. Testis of CPA-treated mice showed many histological alterations including appearance of irregular seminiferous tubules, reduction in the number of all spermatogenic cells, degeneration of Leydig cells and appearance of intertubular hemorrhage. Concerning the ultrastructural changes, abnormalities in spermatogonia (A and B), spermatocytes, round and elongated spermatids were observed. Degenerated Sertoli cells and degenerated interstitial tissue with abnormal Leydig cells were also seen. Moreover, administration of CPA to animals significantly increased malondialdehyde (MDA, lipid peroxidation marker) and decreased superoxide dismutase (SOD) and catalase (CAT). These changes were time-dependent. Treating animals with CPA and fenugreek seed extract (0.4 g/kg body weight) led to an improvement in the histological and ultrastructural pictures of the testis together with reduction in the level of serum MDA and increase in the activities of serum SOD and CAT. In conclusion, the results of the present work indicated that fenugreek had ameliorative effect against testis damage induced by CPA and this may be mediated by its potent antioxidant activities.

Sperm DNA integrity in men treated for childhood cancer

PURPOSE

It is not known whether childhood cancer and its treatment are associated with sperm DNA damage, which subsequently affects fertility and might be transmitted to the offspring. The aim of this study is to assess DNA fragmentation index (DFI) as an indicator of sperm DNA integrity in childhood cancer survivors (CCS), with treatment regimen taken into account.

EXPERIMENTAL DESIGN

In 99 CCS and 193 age-matched healthy controls, DFI was assessed by using sperm chromatin structure assay.

RESULTS

In the whole group of CCS, DFI was increased compared with the controls, with borderline statistical significance [mean difference, 1.8%; 95% confidence interval (95% CI), -0.0088%-3.7%]. Those treated with radiotherapy only (mean difference, 6.0%; 95% CI, 1.6-10%) or surgery only (mean difference, 2.9%; 95% CI, 0.083-5.8%) had statistically significantly higher DFI than the controls. The odds ratio (OR) for having DFI >20%, which is associated with reduced fertility, was significantly increased in CCS compared with the control group (OR, 2.2; 95% CI, 1.1-4.4). For the radiotherapy-only group, the OR was even higher (OR, 4.9; 95% CI, 1.3-18). DFI was not associated with dose of scattered testicular irradiation or type of chemotherapy given.

CONCLUSIONS

DFI was increased in CCS, with those treated with chemotherapy being the only exception. This sperm DNA impairment may be associated with the disease per se rather than due to the treatment, and may have negative consequences in terms of fertility and risk of transmission to the offspring.

Fertility of male survivors of childhood cancer: a report from the Childhood Cancer Survivor Study

PURPOSE

This study was undertaken to determine the effect of treatment for childhood cancer on male fertility.

PATIENTS AND METHODS

We reviewed the fertility of male Childhood Cancer Survivor Study survivor and sibling cohorts who completed a questionnaire. We abstracted the chemotherapeutic agents administered, the cumulative dose of drug administered for selected drugs, and the doses and volumes of all radiation therapy from medical records. Risk factors for siring a pregnancy were evaluated using Cox proportional hazards models.

RESULTS

The 6,224 survivors age 15 to 44 years who were not surgically sterile were less likely to sire a pregnancy than siblings (hazard ratio [HR], 0.56; 95% CI, -0.49 to 0.63). Among survivors, the HR of siring a pregnancy was decreased by radiation therapy of more than 7.5 Gy to the testes (HR, 0.12; 95% CI, -0.02 to 0.64), higher cumulative alkylating agent dose (AAD) score or treatment with cyclophosphamide (third tertile HR, 0.42; 95% CI, -0.31 to 0.57) or procarbazine (second tertile HR, 0.48; 95% CI, -0.26 to 0.87; third tertile HR, 0.17; 95% CI, -0.07 to 0.41). Compared with siblings, the HR for ever siring a pregnancy for survivors who had an AAD score = 0, a hypothalamic/pituitary radiation dose = 0 Gy, and a testes radiation dose = 0 Gy was 0.91 (95% CI, 0.73 to 1.14; P = .41).

CONCLUSION

This large study identified risk factors for decreased fertility that may be used for counseling male cancer patients.

Protective effect of the immunomodulator AS101 against cyclophosphamide-induced testicular damage in mice

BACKGROUND

Cyclophosphamide (Cy), a widely used anticancer drug, is associated with significant testicular damage and sterility. Co-administration of the immunomodulating compound AS101 during chemotherapy treatments was previously shown to protect organs against cytotoxic damage, without attenuating the drug's anticancer effect. In this animal study, we investigated the effect of AS101 on testicular damage, sperm DNA damage and infertility induced by Cy. Akt and glycogen synthase kinase-3beta (GSK-3beta) phosphorylation were investigated as a possible chemoprotective mechanism.

METHODS

Mature male mice, 10 in each group, were injected intraperitoneally with 200 mg/kg Cy once a week for 5 weeks, with or without concurrent treatment with 10 microg per mouse AS101 three times per week. Damage to testicular tubules and sperm production was determined, sperm chromatin damage was analyzed and fertility was gauged. Akt and GSK-3beta phosphorylation were evaluated.

RESULTS

Co-treatment with AS101 during the course of Cy administration significantly reduced the percentage of damaged seminiferous tubules (76.0 +/- 10.8% versus 40.3 +/- 2.6%), and reduced sperm DNA fragmentation (%DFI) from 44.7 +/- 1.0% to 25 +/- 6.5%. Co-treatment with AS101 also partially protected against the decrease in numbers of impregnated females and litter size. AS101 increased Akt and GSK-3beta phosphorylation.

CONCLUSIONS

Our results indicate that AS101 can significantly protect against Cy-induced testicular damage and sperm DNA damage, probably by acting through Akt/GSK-3beta phosphorylation.

Therapy Insight: preserving fertility in cyclophosphamide-treated patients with rheumatic disease

Cyclophosphamide remains a necessary treatment for severe rheumatic diseases, despite the continued search for alternative therapies with less gonadal toxicity. The risk of premature gonadal failure and sterility might lead young patients to delay treatment with cyclophosphamide. The patient's age at treatment and the cumulative dose received remain important risk factors for cyclophosphamide-induced gonadal failure in both males and females. Estrogen-containing oral contraceptives for females and testosterone for males are suggested to reduce the gonadal toxicity of cyclophosphamide, although few studies support these interventions. Owing to increased side effects, hormonal therapy is often avoided in patients with edema, hypertension, nephrotic syndrome or antiphospholipid antibodies. Agonists and antagonists of gonadotropin receptors are under study. Gonadotropin-receptor agonists might have beneficial effects in addition to suppression of sex-hormone production. The outcome of attempted cryopreservation of eggs, embryos or ovaries remains uncertain for women seeking to preserve their reproductive potential. Storing male gametes before chemotherapy is widely practiced and technically successful. As recovery of menses or production of testosterone does not predict individual fertility, identification of biomarkers of gonadal function and reserve, including serum levels of several hormones, ultrasonographic measurements of ovarian volume and antral follicle count, are necessary.

Does ifosfamide affect gonadal function?

BACKGROUND

Gonadal dysfunction and infertility are potential late effects of cancer therapy. Ifosfamide, an alkylating agent structurally related to cyclophosphamide, is thought to cause gonadal dysfunction, though there is little published evidence.

PROCEDURE

Patients treated on sarcoma protocols containing ifosfamide as the only potential gonadotoxic agent, were evaluated, assessing pubertal development, menstrual history in the females and semen analysis in males. Biochemical evaluation included measurement of gonadotrophins, inhibin B and anti-mullerian hormone (AMH).

RESULTS

All 32 males progressed normally through puberty. No gonadal dysfunction was seen at a total ifosfamide dose of <60 g/m(2). In those with a dose >60 g/m(2), two-thirds of those who underwent semen analysis were subfertile, 31% had elevated FSH and 50% showed decreased inhibin B supporting evidence of germ cell failure. All 13 females progressed through puberty normally and had regular menses. Biochemical results were in line with published data except for AMH levels, which were lower compared with an age-matched reference group. Nine patients not recruited into the study were known to have had 11 live births.

CONCLUSIONS

Males appear more susceptible than females to ifosfamide gonadotoxicity. There may be a dose in males below which the risk of subfertility is low. In females there is preliminary evidence of reduction in ovarian reserve as measured by AMH levels, which may potentially lead to an early menopause and a reduction in the window of fertility.