Role of mTOR Signaling in Female Reproduction

Mammalian target of rapamycin (mTOR) is a conserved serine/threonine kinase of the phosphatidylinositol kinase-related kinase family that regulates cell growth, metabolism, and autophagy. Extensive research has linked mTOR to several human diseases including cancer, neurodegenerative disorders, and aging. In this review, recent publications regarding the mechanisms underlying the role of mTOR in female reproduction under physiological and pathological conditions are summarized. Moreover, we assess whether strategies to improve or suppress mTOR expression could have therapeutic potential for reproductive diseases like premature ovarian failure, polycystic ovarian syndrome, and endometriosis.

Recent advances in oocyte and ovarian tissue cryopreservation and transplantation

Options for preserving fertility in women include well-established methods such as fertility-sparing surgery, shielding to reduce radiation damage to reproductive organs, and emergency in-vitro fertilisation after controlled ovarian stimulation, with the aim of freezing embryos. The practice of transfering frozen or thawed embryos has been in place for over 25 years, and today is a routine clinical treatment in fertility clinics. Oocytes may also be frozen unfertilised for later thawing and fertilisation by intracytoplasmic sperm injection in vitro. In recent years, oocyte cryopreservation methods have further developed, reaching promising standards. More than 1000 children are born worldwide after fertilisation of frozen and thawed oocytes. Nevertheless, this technique is still considered experimental. In this chapter, we focus on options for fertility preservation still in development that can be offered to women. These include freezing of oocytes and ovarian cortex and the transplantation of ovarian tissue.

Ovarian tissue cryopreservation for fertility preservation: clinical and research perspectives

BACKGROUND

Small case series have reported successful live births after ovarian tissue cryopreservation and orthotopic transplantation, demonstrating that it can be of value in increasing the chance of successful pregnancy after treatment for cancer and other fertility-impacting diseases in adult women.

OBJECTIVE AND RATIONALE

This review is intended to set out the current clinical issues in the field of ovarian tissue cryopreservation, and elucidate the status of laboratory studies to address these.

SEARCH METHODS

We reviewed the English-language literature on ovarian tissue cryopreservation and in vitro maturation (IVM) of ovarian follicles.

OUTCOMES

Ovarian tissue cryopreservation is increasingly used for fertility preservation and, whilst areas for development remain (optimal patient selection, minimizing risk of contamination by malignant cells and IVM protocols), there are emerging data as to its efficacy. We review the current status of ovarian tissue cryopreservation in girls and young women facing loss of fertility from treatment of cancer and other serious diseases. Increasingly large cohort studies are reporting on success rates from ovarian tissue cryopreservation giving an indication of likely success rates. Patient selection is necessary to ensure the safety and effectiveness of this approach, especially in the very experimental situation of its application to prepubertal girls. There are continuing developments in supporting follicle development in vitro.

LIMITATIONS REASONS FOR CAUTION

The evidence base consists largely of case series and cohort studies, thus there is the possibility of bias in key outcomes. In vitro development of human ovarian follicles remains some way from clinical application.

WIDER IMPLICATIONS OF THE FINDINGS

Ovarian tissue cryopreservation is becoming established as a valuable approach to the preservation of fertility in women. Its application in prepubertal girls may be of particular value, as it offers the only approach in this patient group. For both girls and young women, more accurate data are needed on the likelihood of successful childbirth after this procedure and the factors that underpin successful application of this approach, which will lead to its more effective use.

STUDY FUNDING/COMPETING INTERESTS

The author's work in this field is supported by Medical Research Grant (MRC) grants G0901839 and MR/L00299X/1 and partially undertaken in the MRC Centre for Reproductive Health which is funded by MRC Centre grant MR/N022556/1. The authors declare that there is no conflict of interest that could prejudice the impartiality of the present research.

Oncofertility-An emerging discipline rather than a special consideration

Originally absent from the oncologist's consult, then placed in a 'quality of life' rubric, oncofertility should now be an essential part of a comprehensive cancer treatment plan in patients of reproductive age, including adolescents and young adults (AYAs). Oncofertility encompasses the endocrine health of the patient, as well as fertility management options. Thus, pubertal transitions in males and females, bone health, and menstrual health are all part of this discipline, enabling practitioners to work in interdisciplinary teams to solve problems in reproductive health. This review provides a summary of the essential considerations required for the assessement of reproductive risk and choice of fertility preservation options as well as considerations for developing oncofertility services for AYAs.

Anticancer treatments and female fertility: clinical concerns and role of oncologists in oncofertility practice

INTRODUCTION

Anticancer treatments such as aggressive chemotherapy and radiotherapy have deleterious gonadotoxic side effects and are considered the most common causes of pathological and iatrogenic fertility loss in women. Areas covered: In order to preserve fertility of young women and girls with cancer, several established, experimental, and debatable options can be offered in the emerging field of oncofertility. This article reviews the effects of anticancer treatments on female fertility and discusses the current challenges and future directions of fertility preservation options that can be offered to the female patients with cancer. Expert commentary: Although promising, several medical, economic, social and legal barriers face oncofertility practice around the globe especially in underserved areas. To overcome such barriers, more effective solutions should be provided to spread awareness and enhance communication between patients, oncologists and gynecologists. Early referral by oncologists before initiation of chemotherapy and radiotherapy is an important key factor for success in female fertility preservation strategies.

Antimüllerian hormone as a measure of reproductive function in female childhood cancer survivors

OBJECTIVE

To evaluate the utility of measuring antimüllerian hormone (AMH) in childhood cancer survivors to assess ovarian reserve, pubertal status, and fertility potential.

DESIGN

Cross-sectional study.

SETTING

Academic medical center.

PATIENT(S)

Fifty-three female childhood cancer survivors, median age 13.9 years (range: 9-25 years) recruited at least 1 year from completion of cancer therapy.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Serum AMH, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and estradiol measurements, pubertal/menstrual history and Tanner staging, with risk of gonadotoxicity classified as low or high based on chemotherapy agent and pelvic/abdominal radiation.

RESULT(S)

Thirty-one of the 53 patients (58%) in the cohort had diminished ovarian reserve (DOR) detected by an AMH value <1 ng/mL. We detected DOR by a FSH value of >12 IU/mL in 17 patients (32%). The patients exposed to high-risk chemotherapy or pelvic radiation were at statistically significantly higher risk for DOR as measured by their AMH level. The AMH level was also statistically significantly lower in the patients who had delayed puberty.

CONCLUSION(S)

Using the serum gonadotropins level to screen childhood cancer survivors for ovarian failure is a suboptimal method. The AMH value identified the patients at risk for delayed puberty and those who could benefit from fertility preservation counseling, which makes AMH perhaps the optimal screening tool for assessing ovarian reserve in this population.

Anti-Müllerian hormone as a marker of ovarian reserve and premature ovarian insufficiency in children and women with cancer: a systematic review

BACKGROUND

Female patients undergoing anticancer treatment are at elevated risk of adverse ovarian outcomes including infertility and premature ovarian insufficiency (POI), which is associated with short- and long-term health risks. Anti-Müllerian hormone (AMH) is a key biomarker of ovarian reserve, but its role prior to and after cancer treatment is less well understood.

OBJECTIVE AND RATIONALE

To conduct a systematic review evaluating AMH as a biomarker of ovarian reserve and POI before and after anticancer treatment, which has become a pressing clinical issue in reproductive medicine. There are a large number of observational studies, but differences in patient groups, cancer diagnoses and study design make this a confusing field that will benefit from a thorough and robust review.

SEARCH METHODS

A systematic literature search for AMH in women with cancer was conducted in PubMed, Embase and Cochrane Central Register of Controlled Trials up to 1 April 2021. Bias review was conducted using the Risk of Bias In Non-randomized Studies of Interventions (ROBINS-I) protocol along with qualitative assessment of quality. Exploratory subgroups were established based on age, cancer type and length of follow-up.

OUTCOMES

Ninety-two publications (N = 9183 patients) were included in this analysis after quality and bias review. Reduced/undetectable AMH was consistently identified in 69/75 studies (92%) following chemotherapy or radiotherapy, with reductions ranging from 42% to concentrations below the limit of detection, and many reporting mean or median declines of ≥90%. Where longitudinal data were analysed (42 studies), a majority (33/42 (79%)) of studies reported at least partial recovery of AMH at follow-up, however, effect estimates were highly variable, reflecting that AMH levels were strongly impacted by anticancer treatment (i.e. the chemotherapy regimen used and the number of treatment cycles need), with recovery and its degree determined by treatment regimen, age and pre-treatment AMH level. In 16/31 (52%) publications, oligo/amenorrhoea was associated with lower post-treatment AMH consistent with impending POI, although menstruation and/or pregnancy were reported in patients with low or undetectable AMH. Long-term (>5 years) follow-up of paediatric patients following cancer treatment also found significantly lower AMH compared with control groups in 14/20 (70%) of studies, with very variable effect sizes from complete loss of AMH to full recovery depending on treatment exposure, as in adult patients.

WIDER IMPLICATIONS

AMH can be used to identify the damaging effect of cancer treatments on ovarian function. This can be applied to individual women, including pre-pubertal and adolescent girls, as well as comparing different treatment regimens, ages and pre-treatment AMH levels in populations of women. While there was evidence for its value in the diagnosis of POI after cancer treatment, further studies across a range of diagnoses/treatment regimens and patient ages are required to clarify this, and to quantify its predictive value. A major limitation for the use of AMH clinically is the very limited data relating post-treatment AMH levels to fertility, duration of reproductive lifespan or time to POI; analysis of these clinically relevant outcomes will be important in further research.

New advances in fertility preservation for pediatric cancer patients

PURPOSE OF REVIEW

The number of pediatric cancer survivors is growing rapidly as treatments become more effective. However, many current regimens cause gonadotoxicity and permanent infertility, significantly impacting quality of life. The purpose of this review is to update pediatric oncologists on risk factors for cancer treatment-associated gonadotoxicity, current methods for fertility preservation, and new scientific advances in this area.

RECENT FINDINGS

Infertility is an enormous quality-of-life issue for pediatric cancer survivors and their families. Numerous treatment options are already available to prevent infertility in patients at risk. It is important to counsel patients at risk and initiate management for fertility preservation prior to beginning therapy. Preclinical research indicates that it may be possible to bank gonadal tissues from patients for subsequent re-implantation after therapy or expansion of germ cells in vitro. Further translational studies are required to advance these technologies into clinical use.

SUMMARY

Pediatric cancer survivors are at risk for long-term treatment-related gonadal failure and infertility. Counseling and treatment should begin prior to initiating chemo or radiation therapy. Recent scientific advances in understanding germ cell biology should eventually generate new clinical strategies to maintain fertility in pediatric cancer patients.

'An ounce of prevention is worth a pound of cure': the case for and against GnRH-agonist for fertility preservation

The late effects of cancer treatment have recently gained a worldwide interest among reproductive endocrinologists, oncologists, and all health-care providers, and the protection against iatrogenic infertility caused by chemotherapy assumes a high priority. Here, we summarize the case for and against using GnRH-agonist for fertility preservation and minimizing chemotherapy-induced gonadotoxicity. The rationale and philosophy supporting its use is that preventing premature ovarian failure (POF) is preferable to treating it, following the dictum: 'an ounce of prevention is worth a pound of cure'. Despite many publications on this subject, there are many equivocal issues necessitating summary. Until now, 20 studies (15 retrospective and 5 randomized, controlled trials) have reported on 1837 patients treated with GnRH-a in parallel to chemotherapy, showing a significant decrease in POF rate in survivors versus 9 studies reporting on 593 patients, with results not supporting GnRH-a use. Patients treated with GnRH-a in parallel to chemotherapy preserved their cyclic ovarian function in 91% of cases when compared with 41% of controls, with a pregnancy rate of 19-71% in the treated patients. Furthermore, seven meta-analyses have concluded that GnRH-a are beneficial and may decrease the risk of POF in survivors. However, controversy still remains regarding the efficiency of GnRH-a in preserving fertility. Since not all the methods involving fertility preservation are unequivocally successful and safe, these young patients deserve to be informed of all the various modalities to minimize gonadal damage and preserve ovarian function and future fertility. Combining several methods for a specific patient may increase the odds for minimally invasive fertility preservation.

Molecular Mechanism and Prevention Strategy of Chemotherapy- and Radiotherapy-Induced Ovarian Damage

Fertility preservation is an emerging discipline, which is of substantial clinical value in the care of young patients with cancer. Chemotherapy and radiation may induce ovarian damage in prepubertal girls and young women. Although many studies have explored the mechanisms implicated in ovarian toxicity during cancer treatment, its molecular pathophysiology is not fully understood. Chemotherapy may accelerate follicular apoptosis and follicle reservoir utilization and damage the ovarian stroma via multiple molecular reactions. Oxidative stress and the radiosensitivity of oocytes are the main causes of gonadal damage after radiation treatment. Fertility preservation options can be differentiated by patient age, desire for conception, treatment regimen, socioeconomic status, and treatment duration. This review will help highlight the importance of multidisciplinary oncofertility strategies for providing high-quality care to young female cancer patients.

Preserving fertility when choosing chemotherapy regimens - the role of gonadotropin-releasing hormone agonists

INTRODUCTION

The late effects of cancer treatment have recently gained a worldwide ubiquitous interest among reproductive endocrinologists, oncologists, and all health care providers. Despite many publications on this subject, there are many equivocal issues necessitating summary. The case for and against using GnRH-agonist for fertility preservation is summarized with the rationale that preventing ovarian failure may be better than treating it.

AREAS COVERED

We searched Medline in the last 10 years using terms: 'fertility preservation', 'female chemotherapy', 'Gonadotropin-releasing hormone (GnRH) analogues', 'GnRH agonists' 'gonadotoxicity', and 'cancer treatment'. We included mainly publications from the past 7 years, but did not exclude previous, commonly referenced publications. Here, we summarize the various methods available for fertility preservation and minimizing chemotherapy induced gonadotoxicity.

EXPERT OPINION

Until now, 20 studies (15 retrospective and 5 randomized controlled trial) have reported on 2038 patients treated with GnRH-a in parallel to chemotherapy, showing a significant decrease in premature ovarian failure (POF) rate in survivors versus 8 studies reporting on 509 patients, with negative results. Patients treated with GnRH-a in parallel to chemotherapy preserved their cyclic ovarian function in 91% of cases as compared to 41% of controls, with a pregnancy rate of 19 - 71% in the treated patients. Furthermore, over 10 recent meta-analyses have concluded that GnRH-a are beneficial and may decrease the risk of POF in survivors. Because most of the methods involving ovarian or egg cryopreservation are not yet clinically established and unequivocally successful, these young patients deserve to be informed with all the various modalities to minimize gonadal damage and preserve ovarian function and future fertility. Combining the various modalities for a specific patient may increase the odds of preservation of future fertility.

Advances in the Treatment and Prevention of Chemotherapy-Induced Ovarian Toxicity

Due to improvements in chemotherapeutic agents, cancer treatment efficacy and cancer patient survival rates have greatly improved, but unfortunately gonadal damage remains a major complication. Gonadotoxic chemotherapy, including alkylating agents during reproductive age, can lead to iatrogenic premature ovarian insufficiency (POI), and loss of fertility. In recent years, the demand for fertility preservation has increased dramatically among female cancer patients. Currently, embryo and oocyte cryopreservation are the only established options for fertility preservation in women. However, there is growing evidence for other experimental techniques including ovarian tissue cryopreservation, oocyte in vitro maturation, artificial ovaries, stem cell technologies, and ovarian suppression. To prevent fertility loss in women with cancer, individualized fertility preservation options including established and experimental techniques that take into consideration the patient's age, marital status, chemotherapy regimen, and the possibility of treatment delay should be provided. In addition, effective multidisciplinary oncofertility strategies that involve a highly skilled and experienced oncofertility team consisting of medical oncologists, gynecologists, reproductive biologists, surgical oncologists, patient care coordinators, and research scientists are necessary to provide cancer patients with high-quality care.

Comparative gonadotoxicity of the chemotherapy drugs cisplatin and carboplatin on prepubertal mouse gonads

The treatment of childhood cancer with chemotherapy drugs can result in infertility in adulthood. Newer generations of drugs are developed to replace parent drugs, with the potential benefits of less toxic side effects. For platinum alkylating-like drugs, in contrast to the parent compound cisplatin, the newer-generation drug carboplatin is reported to have reduced toxicity in some respects, despite being administered at 5-15 times higher than the cisplatin dose. Whether carboplatin is also less toxic than cisplatin to the reproductive system is unknown. Here we compare the gonadotoxic impact of cisplatin and carboplatin on female and male mouse prepubertal gonads. In vitro cultured CD1 mouse ovaries or testis fragments were exposed to either cisplatin or carboplatin for 24 h on Day 2 of culture and analysed by Day 6. A dose response for each drug was determined for the ovary (0.5, 1 & 5 μg/ml cisplatin and 1, 5 & 10 μg/ml carboplatin) and the testis (0.01, 0.05 & 0.1 μg/ml cisplatin and 0.1, 0.5 & 1 μg/ml carboplatin). For the ovary, unhealthy follicles were evident from 1 μg/ml cisplatin (73% unhealthy, P = 0.001) and 5 μg/ml carboplatin (84% unhealthy, P = 0.001), with a concomitant reduction in follicle number (P = 0.001). For the testis, the proliferating germ cell population was significantly reduced from 0.05 μg/ml cisplatin (73% reduction, P = 0.001) and 0.5 μg/ml carboplatin (75% reduction, P = 0.001), with no significant impact on the Sertoli cell population. Overall, results from this in vitro animal model study indicate that, at patient equivalent concentrations, carboplatin is no less gonadotoxic than cisplatin.

Oncofertility in Canada: an overview of Canadian practice and suggested action plan

BACKGROUND

Cancer can be a devastating diagnosis. In particular, malignancy and its indicated treatments have profoundly negative effects on the fertility of young cancer patients. Oncofertility has emerged as a new interdisciplinary field to address the issue of gonadotoxicity associated with cancer therapies and to facilitate fertility preservation. In Canada, these fertility issues are often inadequately addressed despite the availability of resources. The goal of this four-part series is to facilitate systemic improvements in fertility preservation for adolescent and young adult Canadians with a new diagnosis of cancer.

METHODS

Here, we describe the services currently available in Canada and the challenges associated with their utilization. Finally, we outline strategies to help maximize and facilitate fertility preservation in the young cancer patient.

RESULTS

Despite an existing infrastructure to the oncofertility system in Canada, the ability of that system's components to function together and to coordinate patient care is a challenge. Areas of weakness include poor access and referral to fertility services, a lack of readily available education for patients and health care providers, and inconsistent interdisciplinary coordination in patient care.

CONCLUSIONS

The implementation of a framework for multidisciplinary resource allocation, education, patient referral, and established lines of communication may facilitate a functional oncofertility system in Canada.

Irinotecan metabolite SN38 results in germ cell loss in the testis but not in the ovary of prepubertal mice

STUDY QUESTION

Does the Irinotecan metabolite 7-ethyl-10-hydroxycamptothecan (SN38) damage the gonads of male and female prepubertal mice?

SUMMARY ANSWER

The Irinotecan metabolite SN38 reduces germ cell numbers within the seminiferous tubules of mouse testes at concentrations that are relevant to cancer patients, while in contrast it has little if any effect on the female germ cell population.

WHAT IS KNOWN ALREADY

Little is known about the role of the chemotherapeutic agent Irinotecan on female fertility, with only one article to date reporting menopausal symptoms in perimenopausal women treated with Irinotecan, while no data are available either on adult male fertility or on the impact of Irinotecan on the subsequent fertility of prepubertal cancer patients, female or male.

STUDY DESIGN SIZE, DURATION

Male and female gonads were obtained from postnatal day 5 C57BL/6 mice and exposed in vitro to a range of concentrations of the Irinotecan metabolite SN38: 0.002, 0.01, 0.05, 0.1 or 1 µg ml^–1 for the testis and 0.1, 1, 2.5 or 5 µg ml^–1 for the ovary, with treated gonads compared to control gonads not exposed to SN38. SN38 was dissolved in 0.5% dimethyl sulfoxide, with controls exposed to the same concentration of diluent. The number of testis fragments used for each analysis ranged between 3 and 9 per treatment group, while the number of ovaries used for each analysis ranged between 4 and 12 per treatment group.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Neonatal mouse gonads were developed in vitro, with tissue analysed at the end of the 4–6 day culture period, following immunofluorescence or hematoxylin and eosin staining. Statistical analyses were performed using one-way ANOVA followed by Bonferroni post-hoc test for normally distributed data and Kruskal-Wallis test followed by Dunns post-test for non-parametric data.

MAIN RESULTS AND THE ROLE OF CHANCE

Abnormal testis morphology was observed when tissues were exposed to SN38, with a smaller seminiferous tubule diameter at the highest concentration of SN38 (1 µg ml⁻¹, p < 0.001 versus control) and increased number of Sertoli cell-only tubules at the two highest concentrations of SN38 (0.1 µg ml⁻¹, p < 0.001; 1 µg ml⁻¹, p < 0.0001, both versus control). Within seminiferous tubules, a dose response decrease was observed in both germ cell number (mouse vasa homologue (MVH)-positive cells) and in proliferating cell number (bromodeoxyuridine (BrdU)-positive cells), with significance reached at the two highest concentrations of SN38 (0.1 µg ml⁻¹, p < 0.01 for both; 1 µg ml⁻¹, p < 0.001-MVH, p < 0.01-BrdU; all versus control). No change was seen in protein expression of the apoptotic marker cleaved caspase 3. Double immunofluorescence showed that occasional proliferating germ cells were present in treated testes, even after exposure to the highest drug concentration. When prepubertal ovaries were treated with SN38, no effect was seen on germ cell number, apoptosis or cell proliferation, even after exposure to the highest drug concentrations.

LIMITATIONS REASONS FOR CAUTION

As with any study using in vitro experiments with an experimental animal model, caution is required when extrapolating the present findings to humans. Differences between human and mouse spermatogonial development also need to be considered when assessing the effect of chemotherapeutic exposure. However, the prepubertal testes and ovaries used in the present studies contain germ cell populations that are representative of those found in prepubertal patients, and experimental tissues were exposed to drug concentrations within the range found in patient plasma.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings demonstrate that the prepubertal mouse ovary is relatively insensitive to exposure to the Irinotecan metabolite SN38, while it induces a marked dose-dependent sensitivity in the testicular germ cell population. The study identifies the importance of further investigation to identify the risk of infertility in young male cancer patients treated with Irinotecan.

LARGE SCALE DATA

None.

STUDY FUNDING AND COMPETING INTEREST(S)

Work supported by Medical Research Grant (MRC) grant G1002118 and Children with Cancer UK grant 15-198. The authors declare that there is no conflict of interest that could prejudice the impartiality of the present research.

The PREgnancy and FERtility (PREFER) Study Investigating the Need for Ovarian Function and/or Fertility Preservation Strategies in Premenopausal Women With Early Breast Cancer

BACKGROUND

Offering ovarian function and/or fertility preservation strategies in premenopausal women with newly diagnosed breast cancer candidates to undergo chemotherapy is standard of care. However, few data are available on uptake and main reasons for refusing these options.

METHODS

The PREFER study (NCT02895165) is an observational, prospective study enrolling premenopausal women with early breast cancer, aged between 18 and 45 years, candidates to receive (neo)adjuvant chemotherapy. Primary objective is to collect information on acceptance rates and reasons for refusal of the proposed strategies for ovarian function and/or fertility preservation available in Italy.

RESULTS

At the study coordinating center, 223 patients were recruited between November 2012 and December 2020. Median age was 38 years (range 24 - 45 years) with 159 patients (71.3%) diagnosed at ≤40 years. Temporary ovarian suppression with gonadotropin-releasing hormone agonists (GnRHa) was accepted by 58 out of 64 (90.6%) patients aged 41-45 years and by 151 out of 159 (95.0%) of those aged ≤40 years. Among patients aged ≤40 years, 57 (35.8%) accepted to access the fertility unit to receive a complete oncofertility counseling and 29 (18.2%) accepted to undergo a cryopreservation technique. Main reasons for refusal were fear of delaying the initiation of antineoplastic treatments and contraindications to the procedure or lack of interest in future childbearing. Patients with hormone-receptor positive breast cancer had a tendency for a higher acceptance rates of ovarian function and/or fertility preservation strategies than those with hormone-receptor negative disease.

CONCLUSIONS

More than 90% of premenopausal women with early breast cancer, and particularly those with hormone receptor-positive disease, were concerned about the potential risk of chemotherapy-induced premature ovarian insufficiency and/or infertility and accepted GnRHa administration. Less than 1 out of 5 women aged ≤40 years accepted to undergo cryopreservation strategies.

Fertility preservation in reproductive-age women facing gonadotoxic treatments

BACKGROUND

Advancements in the treatments for cancer and autoimmune and other hematologic conditions continue to improve survival and cure rates. Despite those changes, various gonadotoxic agents and other treatments can still compromise the future fertility of many women. Progress in medical and surgical reproductive technologies has helped to offset the reproductive consequences of the use of gonadotoxic therapies, and allows for future fertility and normal pregnancy.

METHODS

A review of the literature was performed to outline the pathophysiology of gonadotoxicity from various treatments. The success of fertility preservation, fertility sparing, and cryopreservation options are reviewed. Barriers and facilitators to referral and oncofertility treatment in Canada are also outlined.

RESULTS

According to the quality of the evidence, recommendations are made for fertility assessment, patient referral, cryopreservation, and other assisted reproductive technologies.

CONCLUSIONS

To ensure ongoing fertility in women undergoing gonadotoxic treatments, assisted reproductive technologies can be combined with a multidisciplinary approach to patient assessment and referral.

Reproductive ability in survivors of childhood, adolescent, and young adult Hodgkin lymphoma: a review

BACKGROUND

Owing to a growing number of young and adolescent Hodgkin lymphoma (HL) survivors, awareness of (long-term) adverse effects of anticancer treatment increases. The risk of impaired reproductive ability is of great concern given its impact on quality of life. There is currently no review available on fertility after childhood HL treatment.

OBJECTIVE AND RATIONALE

The aim of this narrative review was to summarize existing literature on different aspects of reproductive function in male and female childhood, adolescent, and young adult HL survivors.

SEARCH METHODS

PubMed and EMBASE were searched for articles evaluating fertility in both male and female HL survivors aged <25 years at diagnosis. In females, anti-Müllerian hormone (AMH), antral follicle count, premature ovarian insufficiency (POI), acute ovarian failure, menstrual cycle, FSH, and pregnancy/live births were evaluated. In males, semen-analysis, serum FSH, inhibin B, LH, testosterone, and reports on pregnancy/live births were included. There was profound heterogeneity among studies and a lack of control groups; therefore, no meta-analyses could be performed. Results were presented descriptively and the quality of studies was not assessed individually.

OUTCOMES

After screening, 75 articles reporting on reproductive markers in childhood or adolescent HL survivors were included. Forty-one papers reported on 5057 female HL survivors. The incidence of POI was 6-34% (median 9%; seven studies). Signs of diminished ovarian reserve or impaired ovarian function were frequently seen (low AMH 55-59%; median 57%; two studies. elevated FSH 17-100%; median 53%; seven studies). Most survivors had regular menstrual cycles. Fifty-one studies assessed fertility in 1903 male HL survivors. Post-treatment azoospermia was highly prevalent (33-100%; median 75%; 29 studies). Long-term follow-up data were limited, but reports on recovery of semen up to 12 years post-treatment exist. FSH levels were often elevated with low inhibin B (elevated FSH 0-100%; median 51.5%; 26 studies. low inhibin B 19-50%; median 45%; three studies). LH and testosterone levels were less evidently affected (elevated LH 0-57%, median 17%; 21 studies and low testosterone 0-43%; median 6%; 15 studies). In both sexes, impaired reproductive ability was associated with a higher dose of cumulative chemotherapeutic agents and pelvic radiotherapy. The presence of abnormal markers before treatment indicated that the disease itself may also negatively affect reproductive function (Females: AMH<p10 9%; one study and Males: azoospermia 0-50%; median 10%; six studies). Reports on chance to achieve pregnancy during survivorship are reassuring, although studies had their limitations and the results are difficult to evaluate. In the end, a diminished ovarian reserve does not exclude the chance of a live birth, and males with aberrant markers may still be able to conceive.

WIDER IMPLICATIONS

This review substantiates the negative effect of HL treatment on gonadal function and therefore young HL survivors should be counseled regarding their future reproductive life, and fertility preservation should be considered. The current level of evidence is insufficient and additional trials on the effects of HL and (current) treatment regimens on reproductive function are needed. In this review, we make a recommendation on reproductive markers that could be assessed and the timing of (repeated) measurements.

Fertility preservation for young adults, adolescents, and children with cancer

Options for fertility preservation (FP) through cryopreservation methods are currently available for young adults, adolescents, and children. Guidelines for FP have been provided by international clinical societies, and emergency procedures aimed at FP have been implemented into clinical practice worldwide. In this article, we review the current data on clinical standards of emergency FP in patients who are facing gonadotoxic effects of cancer treatment, and we also describe the methods that are still under development, usually denoted as experimental. In Sweden, programmes for FP have been established at large university hospitals, thus covering the whole country. The Swedish publicly financed health care covers both assisted reproduction for treatment of infertility and the cryopreservation of gametes or gonadal tissue when there is a medical indication, such as the risk to become infertile due to oncologic treatment; hence the access to FP is ensured for the whole population. At our centre at Karolinska University Hospital in Stockholm, methods for FP have been offered since 1988. In this article, we also review the oncologic indications for FP in our patient cohort of >3000 individuals during the period 1988-2018.

Oncofertility in Canada: the impact of cancer on fertility

BACKGROUND

Cancer can be a devastating diagnosis. In particular, malignancy and its indicated treatments have profoundly negative effects on the fertility of young cancer patients. Oncofertility has emerged as a new interdisciplinary field to address the issue of gonadotoxicity associated with cancer therapies and to facilitate fertility preservation. In Canada, these fertility issues are often inadequately addressed despite the availability of resources. The goal of this four-part series is to facilitate systemic improvements in fertility preservation for adolescent and young adult Canadians with a new diagnosis of cancer.

METHODS

In this article, we review the gonadotoxic effects of cancer treatment on young men and women of reproductive age.

RESULTS

The detrimental effects of cancer on fertility can be severe and may vary depending on the chemotherapy, radiotherapy, or surgical treatments involved.

CONCLUSIONS

Fertility preservation should be addressed in an effort to mitigate the gonadal damage that may come with cancer therapy.

Testicular tissue cryopreservation for fertility preservation in prepubertal and adolescent boys: A 6 year experience from a Swiss multi-center network

Testicular tissue cryopreservation is the only option of fertility preservation in prepubertal boys. While it is considered experimental, since procedures to obtain mature spermatozoa from prepubertal testicular tissue are still under development, testicular tissue cryopreservation programs have emerged worldwide. Our aim was to study the feasibility and safety of a program of testicular tissue cryopreservation in prepubertal and adolescent boys facing gonadotoxic treatment in three University hospitals in Switzerland. Testicular tissue cryopreservation was accepted by 90% of families, with a total of 35 patients included. The average patient age was 8.5 years (range 7 months to 18.5 years). Malignancies were the most common diagnosis (31 patients, 88.6%) with 16 (45.7%) solid tumors and 15 (42.9%) hematological malignancies. Four (11.4%) patients had a benign condition. The main indication for testicular tissue cryopreservation was conditioning for hematologic stem cell transplantation (25 patients, 71.4%). Testicular tissue was cryopreserved according to the freezing protocol of Louvain Catholic University (Belgium), which includes either only immature testicular tissue freezing, or mature and immature testicular tissue freezing depending on the age of the patient and the presence or absence of haploid cells. The median number of spermatogonia per tubule cross-section was 2 (range 0-6) and spermatozoa were found in only one patient. Tumoral cells were found in one testicular biopsy of a leukemic patient. There were two minor adverse events and none of them required medical treatment or surgical revision. Five patients died during follow-up. Our data demonstrate the feasibility and safety of a program of testicular tissue cryopreservation coordinated by a multidisciplinary team of fertility preservation. Despite the experimental aspect of the procedure, the acceptation rate was high, which highlights the willingness of families and patients to participate in testicular tissue cryopreservation.

Impact of Anti-HER2 Therapy Alone and With Weekly Paclitaxel on the Ovarian Reserve of Young Women With HER2-Positive Breast Cancer

BACKGROUND

The potential gonadotoxicity of anti-HER2 agents remains largely unknown, and limited, conflicting evidence exists for taxanes. Antimüllerian hormone (AMH) is an established biomarker of ovarian reserve that may aid in quantifying anticancer treatment-induced gonadotoxicity.

PATIENTS AND METHODS

The present biomarker analysis of the randomized phase III neoadjuvant NeoALTTO trial included premenopausal women aged ≤45 years at diagnosis of HER2-positive early breast cancer with available frozen serum samples at baseline (ie, before anticancer treatments), at week 2 (ie, the "biological window" of anti-HER2 therapy alone), and/or at the time of surgery (ie, after completing paclitaxel + anti-HER2 therapy, before starting adjuvant chemotherapy).

RESULTS

The present analysis included 130 patients with a median age of 38 years (interquartile ratio [IQR], age 33-42 years). AMH values at the 3 time points differed significantly (P<.001). At baseline, median AMH levels were 1.29 ng/mL (IQR, 0.56-2.62 ng/mL). At week 2, a small but significant reduction in AMH levels was observed (median, 1.10 ng/mL; IQR, 0.45-2.09 ng/mL; P<.001). At surgery, a larger significant decline in AMH levels was observed (median, 0.01 ng/mL; IQR, 0.01-0.03 ng/mL; P<.001). Although the type of anti-HER2 treatment (trastuzumab and/or lapatinib) did not seem to impact the results, age and pretreatment ovarian reserve had a major influence on treatment-induced gonadotoxicity risk.

CONCLUSIONS

This NeoALTTO biomarker analysis showed that anti-HER2 therapies alone had limited gonadotoxicity but that the addition of weekly paclitaxel resulted in marked AMH decline with possible negative implications for subsequent ovarian function and fertility.

Fertility Preservation in Cancer Patients During the Coronavirus (COVID-19) Pandemic

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also identified as Corona virus disease 19 (COVID-19), has recently produced a dramatic and widespread sanitary emergency. However, despite the necessity to assist a substantial number of affected patients, it is also essential to, at the same time, guarantee the usual clinical care, particularly to cancer patients, including fertility preservation (FP) strategies before the beginning of the anti-cancer treatments. The FP techniques for adult female patients include oocyte and embryo cryopreservation, which require both adequate ovarian reserve (OR) and controlled ovarian stimulation (COS) to promote multiple follicular growth. However, ovarian tissue cryopreservation is an additional FP practice suitable when an anti-cancer treatment is urgently required, whereas, for male patients, sperm cryopreservation is a simple and well-adopted procedure. Here, we focus on the current conditions in terms of agreements and rules of FP procedures during this COVID-19 pandemic to achieve and provide useful recommendations for the adoption of these techniques in patients with cancer.

Effect of Multiple Sclerosis and Its Treatments on Male Fertility: Cues for Future Research

Multiple sclerosis is a chronic disease that may lead to different types of symptoms and disabilities. with the better quality of life and decreased disability due to early diagnosis and the availability of disease-modifying therapies (DMTs), the treating physician is increasingly asked to counsel patients on its effects on fertility and reproduction. In particular, reproductive issues are still scarcely studied and discussed in men. Among the still open questions are the following: (a) Does multiple sclerosis cause infertility per sè? (b) Is multiple sclerosis correlated with conditions that increase the risk of infertility? (c) Do DMTs or other therapies for multiple sclerosis impact gonadal function in men? The aim of this review is to provide an overview on the available literature data about the reproductive issues unique to men with multiple sclerosis, underlining the numerous areas where evidence is lacking and, therefore, the priorities for future research.

Inhibiting Necroptosis of Spermatogonial Stem Cell as a Novel Strategy for Male Fertility Preservation

Fertility preservation is a common concern for male cancer survivors of reproductive age. However, except for testicular tissue cryopreservation, which is not very effective, there is no feasible and precise therapy capable of protecting spermatogenesis for prepubertal boys before or during gonadotoxic treatment. This study aims to investigate the effects of inhibiting necroptosis of spermatogonial stem cell (SSC) in fertility preservation. Male mice 12 weeks of age were used to establish gonadotoxicity with two intraperitoneal injections of busulfan at a total dose of 40 mg kg^-1. The mouse model and the primary cultured mouse SSCs were used to characterize the relationship between necroptosis of SSC and gonadotoxicity. Meanwhile, the effects of an inhibitor of necroptosis pathway, RIPA-56, were observed on day 36 in the mouse model of busulfan-induced gonadotoxicity. We found that the number of SSCs was decreased, but the level of necroptosis was upregulated on day 18 after busulfan treatment in testes from gonadotoxic mice. Further experiments in primary cultured cells showed that the necroptosis caused cell death in busulfan-treated SSCs and could be inhibited by RIPA-56. After suppressing the necroptosis of SSCs, the busulfan-induced mice had a decreased loss of spermatogenic cells as shown by histology and an increased Johnsen's score. Moreover, the quantities of SSCs and epididymal spermatozoa were restored after intervention with RIPA-56, indicating a series of beneficial effects by targeting the necroptosis of SSCs in mice undergoing busulfan treatment. In conclusion, our findings reveal that the necroptosis of SSCs plays a critical role in busulfan-induced gonadotoxicity and may be a potential target for male fertility preservation.