Gonadotropin-releasing hormone agonists for the preservation of ovarian function among women with breast cancer who did not use tamoxifen after chemotherapy: a systematic review and meta-analysis

Gynotoxic Effects of Chemotherapy and Potential Protective Mechanisms

Chemotherapy is one of the leading cancer treatments. Unfortunately, its use can contribute to several side effects, including gynotoxic effects in women. Ovarian reserve suppression and estrogen deficiency result in reduced quality of life for cancer patients and are frequently the cause of infertility and early menopause. Classic alkylating cytostatics are among the most toxic chemotherapeutics in this regard. They cause DNA damage in ovarian follicles and the cells they contain, and they can also induce oxidative stress or affect numerous signaling pathways. In vitro tests, animal models, and a few studies among women have investigated the effects of various agents on the protection of the ovarian reserve during classic chemotherapy. In this review article, we focused on the possible beneficial effects of selected hormones (anti-Müllerian hormone, ghrelin, luteinizing hormone, melatonin), agents affecting the activity of apoptotic pathways and modulating gene expression (C1P, S1P, microRNA), and several natural (quercetin, rapamycin, resveratrol) and synthetic compounds (bortezomib, dexrazoxane, goserelin, gonadoliberin analogs, imatinib, metformin, tamoxifen) in preventing gynotoxic effects induced by commonly used cytostatics. The presented line of research appears to provide a promising strategy for protecting and/or improving the ovarian reserve in the studied group of cancer patients. However, well-designed clinical trials are needed to unequivocally assess the effects of these agents on improving hormonal function and fertility in women treated with ovotoxic anticancer drugs.

Ovarian Suppression: Early Menopause and Late Effects

OPINION STATEMENT

Around 90% of breast tumours are diagnosed in the early stage, with approximately 70% being hormone receptor-positive. The cornerstone of adjuvant therapy for early-stage hormone receptor-positive breast cancer is endocrine therapy, tailored according to disease stage, biological characteristics of the tumour, patient's comorbidities, preferences and age. In premenopausal patients with hormone receptor-positive breast cancer, ovarian function suppression is a key component of the adjuvant endocrine treatment in combination with an aromatase inhibitor or tamoxifen. Moreover, it can be used during chemotherapy as a standard strategy for ovarian function preservation in all breast cancer subtypes. In the metastatic setting, ovarian function suppression should be used in all premenopausal patients with hormone receptor-positive breast cancer to achieve a post-menopausal status. Despite its efficacy, ovarian function suppression may lead to several side effects that can have a major negative impact on patients' quality of life if not properly managed (e.g. hot flashes, depression, cognitive impairment, osteoporosis, sexual dysfunction, weight gain). A deep knowledge of the side effects of ovarian function suppression is necessary for clinicians. A correct counselling in this regard and proactive management should be considered a fundamental part of survivorship care to improve treatment adherence and patients' quality of life.

Gonadotropin-releasing hormone agonists for ovarian protection during breast cancer chemotherapy: a systematic review and meta-analysis

IMPORTANCE

The increasing trend of delaying childbirth means that more women are being diagnosed with breast cancer before having given birth to their desired number of children. Although chemotherapy can significantly improve the prognosis of this population, it also causes ovarian damage, including premature ovarian insufficiency and infertility. Gonadotropin-releasing hormone agonists (GnRHa) have shown promising fertility protective activity in premenopausal women, but their clinical usage remains controversial.

OBJECTIVE

Here, we conducted a meta-analysis to assess the efficacy of GnRHa when administered concurrently with chemotherapy that included cyclophosphamide in the prevention of chemotherapy-induced ovarian damage in premenopausal women.

EVIDENCE REVIEW

An extensive literature search was performed using the PubMed, Embase, and Cochrane databases. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were determined.

FINDINGS

Eleven randomized controlled trials with a total of 1,219 participants were included in the analyses. A significantly higher number of women treated with GnRHa experienced the resumption of ovarian function after chemotherapy than those who did not receive this treatment (OR, 3.04; 95% CI, 1.87-4.94; P < 0.001). Regarding spontaneous pregnancy, a statistically significant difference was observed only in hormone receptor-negative participants (OR, 2.06; 95% CI, 1.03-4.11; P = 0.04).

CONCLUSIONS AND RELEVANCE

When treating premenopausal women with breast cancer, the administration of GnRHa concurrently with chemotherapy appeared to improve the resumption rate of ovarian function; however, the spontaneous pregnancy rate only improved in hormone receptor-negative patients. Thus, the use of GnRHa during chemotherapy may represent a feasible strategy for preserving ovarian function in women with breast cancer.

How to Protect Ovarian Function before and during Chemotherapy?

A significant number of women receive a cancer diagnosis before their age of natural menopause. Among these patients, the most frequent neoplasms are breast cancer, gynecological, and hematological malignancies. Premature ovarian insufficiency and infertility are among the most feared short- to long-term consequences of anticancer treatments in premenopausal patients. Both patient- and treatment-related characteristics are key factors in influencing the risk of gonadotoxicity with the use of chemotherapy. The cryopreservation of oocytes/embryos is a standard strategy for fertility preservations offered to young women interested in future family planning, but it does not allow gonadal function protection during chemotherapy. Ovarian suppression with gonadotropin-releasing hormone agonist (GnRHa) during chemotherapy is now recommended as an option to reduce the risk of gonadotoxicity in order to avoid the negative consequences of premature ovarian insufficiency in premenopausal women receiving cytotoxic therapy, including those not interested in fertility preservation. This review summarizes the risk of treatment-induced gonadotoxicity in premenopausal patients and the evidence available on the protective role of administering GnRHa during chemotherapy to preserve ovarian function.

Ovarian damage from chemotherapy and current approaches to its protection

BACKGROUND

Anti-cancer therapy is often a cause of premature ovarian insufficiency and infertility since the ovarian follicle reserve is extremely sensitive to the effects of chemotherapy and radiotherapy. While oocyte, embryo and ovarian cortex cryopreservation can help some women with cancer-induced infertility achieve pregnancy, the development of effective methods to protect ovarian function during chemotherapy would be a significant advantage.

OBJECTIVE AND RATIONALE

This paper critically discusses the different damaging effects of the most common chemotherapeutic compounds on the ovary, in particular, the ovarian follicles and the molecular pathways that lead to that damage. The mechanisms through which fertility-protective agents might prevent chemotherapy drug-induced follicle loss are then reviewed.

SEARCH METHODS

Articles published in English were searched on PubMed up to March 2019 using the following terms: ovary, fertility preservation, chemotherapy, follicle death, adjuvant therapy, cyclophosphamide, cisplatin, doxorubicin. Inclusion and exclusion criteria were applied to the analysis of the protective agents.

OUTCOMES

Recent studies reveal how chemotherapeutic drugs can affect the different cellular components of the ovary, causing rapid depletion of the ovarian follicular reserve. The three most commonly used drugs, cyclophosphamide, cisplatin and doxorubicin, cause premature ovarian insufficiency by inducing death and/or accelerated activation of primordial follicles and increased atresia of growing follicles. They also cause an increase in damage to blood vessels and the stromal compartment and increment inflammation. In the past 20 years, many compounds have been investigated as potential protective agents to counteract these adverse effects. The interactions of recently described fertility-protective agents with these damage pathways are discussed.

WIDER IMPLICATIONS

Understanding the mechanisms underlying the action of chemotherapy compounds on the various components of the ovary is essential for the development of efficient and targeted pharmacological therapies that could protect and prolong female fertility. While there are increasing preclinical investigations of potential fertility preserving adjuvants, there remains a lack of approaches that are being developed and tested clinically.

Fertility Counseling and Preservation for Breast Cancer Patients

Fertility preservation includes all the necessary steps that have to be taken in order to implement a woman's aim for preserving and enhancing her future chances of having her own biological offspring.There are two available choices for patients to maintain their fertility.The first category includes all the preventive methods following the principle of reduction of gonadotoxicity, in terms of using fewer toxic drugs to the ovaries and similarly milder radiation regimens. It also includes the administration of agents that would keep the ovaries suppressed, to minimize the harmful effects of systemic therapy on the oocytes.The second includes necessary artificial reproductive technology procedures for collecting and freezing either gametes (oocytes) or zygotes (embryos). This can be accomplished with immature oocyte pickup followed by in vitro maturation (IVM). Alternatively, mature oocytes can be collected after minimal ovarian stimulation with very small doses or no medication at all, or through a natural cycle.Beyond that, promising is the modern option of ovarian tissue cryopreservation for future transplantation, while the option of oocyte donation is actually an option for childbearing, not for fertility.

The Impact of Chemotherapy on the Ovaries: Molecular Aspects and the Prevention of Ovarian Damage

Cancer treatment, such as chemotherapy, induces early ovarian follicular depletion and subsequent infertility. In order to protect gametes from the gonadotoxic effects of chemotherapy, several fertility preservation techniques—such as oocyte or embryo cryopreservation with or without ovarian stimulation, or cryopreservation of the ovarian cortex—should be considered. However, these methods may be difficult to perform, and the future use of cryopreserved germ cells remains uncertain. Therefore, improving the methods currently available and developing new strategies to preserve fertility represent major challenges in the area of oncofertility. Animal and ovarian culture models have been used to decipher the effects of different cytotoxic agents on ovarian function and several theories regarding chemotherapy gonadotoxicity have been raised. For example, cytotoxic agents might (i) have a direct detrimental effect on the DNA of primordial follicles constituting the ovarian reserve and induce apoptosis; (ii) induce a massive growth of dormant follicles, which are then destroyed; or (ii) induce vascular ovarian damage. Thanks to improvements in the understanding of the mechanisms involved, a large number of studies have been carried out to develop molecules limiting the negative impact of chemotherapy on the ovaries.

Ovarian Function and Fertility Preservation in Breast Cancer: Should Gonadotropin-Releasing Hormone Agonist be administered to All Premenopausal Patients Receiving Chemotherapy?

Chemotherapy-induced premature ovarian insufficiency (POI) is one of the potential drawbacks of chemotherapy use of particular concern for newly diagnosed premenopausal breast cancer patients. Temporary ovarian suppression obtained pharmacologically with the administration of a gonadotropin-releasing hormone agonist (GnRHa) during chemotherapy has been specifically developed as a method to counteract chemotherapy-induced gonadotoxicity with the main goal of diminishing the risk of POI. In recent years, important clinical evidence has become available on the efficacy and safety of this strategy that should now be considered a standard option for ovarian function preservation in premenopausal breast cancer patients, including women who are not interested in conceiving after treatment or that would not be candidates for fertility preservation strategies because of their age. Nevertheless, in women interested in fertility preservation, this is not an alternative to gamete cryopreservation, which remains as the first option to be offered. In this setting, temporary ovarian suppression with GnRHa during chemotherapy should be also proposed following gamete cryopreservation or to women who have no access, refuse, or have contraindications to surgical fertility preservation techniques. In this article, we present an overview about the role of temporary ovarian suppression with GnRHa during chemotherapy in breast cancer patients by addressing the available clinical evidence with the aim of identifying both the best candidates for the use of this strategy and the still existing gray zones requiring further investigation.

Changes in Anti-Müllerian Hormone and Inhibin B in Children Treated for Cancer

Purpose: Diminished reproductive function can be a major late effect of childhood cancer treatment. This study evaluates the changes, and occurrence of possible recovery, in gonadal function markers in children treated for cancer. Methods: Gonadal function markers were measured before (T0), directly after (T1), and 1 year after (T2) end of treatment of childhood cancer. Anti-Müllerian hormone (AMH) was measured in girls and inhibin B in boys and compared to reference populations. Repeated measures analysis of variance and t-tests were employed for data analysis. Results: Baseline gonadal function markers (T0) at diagnosis were available in 129 girls and 150 boys. Paired gonadal function markers were available in 49 girls and 54 boys for T0-T1, and in 27 girls and 32 boys for T1-T2. Gonadal function markers were significantly lower than the reference population at each time point (p < 0.001). Post-menarcheal girls showed a decrease in AMH between T0 and T1 (standard deviation scores [SDS] -0.72 to -1.32, p = 0.007), and in the boys cohort, a decrease in inhibin B (SDS -1.14 to -1.43, p = 0.045) was observed. Impaired gonadal function levels (<5th percentile) at T1 were observed in 15 of 27 (56%) girls and in 15 of 32 (47%) boys. However, gonadal function had recovered at T2 in seven girls and six boys. Conclusion: Our data suggest that gonadal function is already compromised at diagnosis and is further decreased by childhood cancer treatment. Nevertheless, about half of the children with gonadal impairment recovered over time. Evaluation of gonadal function markers before 1 year after end of treatment may therefore be unreliable.

Interdisciplinary Screening, Diagnosis, Therapy and Follow-up of Breast Cancer. Guideline of the DGGG and the DKG (S3-Level, AWMF Registry Number 032/045OL, December 2017) - Part 2 with Recommendations for the Therapy of Primary, Recurrent and Advanced Breast Cancer

Purpose The aim of this official guideline coordinated and published by the German Society for Gynecology and Obstetrics (DGGG) and the German Cancer Society (DKG) was to optimize the screening, diagnosis, therapy and follow-up care of breast cancer. Method The process of updating the S3 guideline published in 2012 was based on the adaptation of identified source guidelines. They were combined with reviews of evidence compiled using PICO (Patients/Interventions/Control/Outcome) questions and with the results of a systematic search of literature databases followed by the selection and evaluation of the identified literature. The interdisciplinary working groups took the identified materials as their starting point and used them to develop suggestions for recommendations and statements, which were then modified and graded in a structured consensus process procedure. Recommendations Part 2 of this short version of the guideline presents recommendations for the therapy of primary, recurrent and metastatic breast cancer. Loco-regional therapies are de-escalated in the current guideline. In addition to reducing the safety margins for surgical procedures, the guideline also recommends reducing the radicality of axillary surgery. The choice and extent of systemic therapy depends on the respective tumor biology. New substances are becoming available, particularly to treat metastatic breast cancer.

Gonadotropin-Releasing Hormone Analogs for Gonadal Protection During Gonadotoxic Chemotherapy: A Systematic Review and Meta-Analysis

OBJECTIVE

A systematic review and meta-analysis was conducted to investigate whether gonadotropin-releasing hormone analogs (GnRHa) have a protective role in women treated with alkylating agents.

DATA SOURCES

Major databases (PubMED, EMBASE, Cochrane Central Register of Controlled Trials), systematic snowballing, and trial registries were screened from the inception dates until September 2017.

METHODS AND STUDY SELECTION

Comparative studies involving reproductive-aged women undergoing chemotherapy with or without coadministration of GnRHa were included. Spontaneous menstrual resumption was assessed as a main outcome. Statistical analyses were performed with STATA 14.2 statistical software. Effect estimates were presented as risk ratios (RR) with 95% confidence intervals (CIs).

RESULTS

The literature search yielded 25 436 citations and 84 papers were assessed in full text. Eighteen studies (11 randomized controlled trials [RCTs] and 7 cohort studies) published between 1987 and 2015 were included in the analysis, revealing a significant protective effect of GnRHa (n = 1043; RR:1.38; 95% CI: 1.18-1.63) although with high heterogeneity (I² = 83.3%). Subgroup analyses revealed a significant benefit of GnRHa cotreatment both in RCTs and in cohort studies. Statistical significance was found in all subgroups by the underlying disease, that is, hematological malignancies, autoimmune diseases, and breast cancer. Sensitivity analyses in GnRH agonist-treated patients, in patients younger than 40 years old, and in patients without supradiaphragmatic radiotherapy also revealed a significant benefit of GnRHa cotreatment.

CONCLUSION

Our results indicate that concurrent GnRHa administration is an effective method to decrease gonadotoxicity of alkylating agents. The presence of low-quality evidence favoring gonadoprotective effect requires a strong recommendation for offering GnRHa coadministration to young women who are to undergo gonadotoxic chemotherapy.

CAPSULE

The present systematic review and meta-analysis shows a significant gonadoprotective effect of gonadotropin-releasing hormone analogs in women treated with alkylating agents.

Female fertility preservation: past, present and future

Anti-cancer therapy, particularly chemotherapy, damages ovarian follicles and promotes ovarian failure. The only pharmacological means for protecting the ovaries from chemotherapy-induced injury is gonadotrophin-releasing hormone agonist, but its efficiency remains controversial; ovarian transposition is used to shield the ovary from radiation when indicated. Until the late 1990s, the only option for fertility preservation and restoration in women with cancer was embryo cryopreservation. The development of other assisted reproductive technologies such as mature oocyte cryopreservation andin vitromaturation of oocytes has contributed to fertility preservation. Treatment regimens to obtain mature oocytes/embryos have been modified to overcome various limitations of conventional ovarian stimulation protocols. In the last decades, several centres have begun cryopreserving ovarian samples containing primordial follicles from young patients before anti-cancer therapy. The first live birth following implantation of cryopreserved-thawed ovarian tissue was reported in 2004; since then, the number has risen to more than 130. Nowadays, ovarian tissue cryopreservation can be combined within vitromaturation and vitrification of oocytes. The use of cryopreserved oocytes eliminates the risk posed by ovarian implantation of reseeding the cancer. Novel methods for enhancing follicular survival after implantation are presently being studied. In addition, researchers are currently investigating agents for ovarian protection. It is expected that the risk of reimplantation of malignant cells with ovarian grafts will be overcome with the putative development of an artificial ovary and an efficient follicle class- and species-dependentin vitrosystem for culturing primordial follicles.

Preservation of gonadal function in women undergoing chemotherapy: a systematic review and meta-analysis of the potential role for gonadotropin-releasing hormone agonists

PURPOSE

To evaluate the available randomized controlled trials (RCTs) in the literature investigating the use of gonadotropin-releasing hormone agonist (GnRHa) co-treatment for ovarian preservation in women receiving chemotherapy.

METHODS

A systematic review of the literature was performed from 1960 through 2017 to identify relevant RCTs. Included patients had lymphoma, ovarian cancer, or breast cancer. The primary outcome was the proportion of women who retained ovarian function after chemotherapy. Extracted data points included study design, patient characteristics, and proportion of women who developed premature ovarian failure (POF). A risk of bias assessment was performed according to the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions. The pooled odds ratio was calculated, and outcomes of individual studies were compared using the random-effects model with the inverse-variance method and the DerSimonian-Laird estimator.

RESULTS

Twenty-nine RCTs were identified, and 10 met criteria for inclusion in the meta-analysis. An analysis of patients who did not develop POF after chemotherapy revealed eight studies supporting the use of GnRHa (OR 1.83; 95% CI 1.34-2.49). The duration of benefit of GnRHa is unclear. An analysis of three studies with outcome data at 2 years revealed a non-significant OR of 0.53 (95% CI 0.22-1.30) for the preservation of ovarian function with GnRHa treatment.

CONCLUSION

GnRHa may have a protective effect against the development of POF after gonadotoxic chemotherapy; however, the duration of benefit is unclear and requires further study.

GnRH in the Human Female Reproductive Axis

Gonadotropin-releasing hormone (GnRH) is recognized as the central regulator of the functions of the pituitary-gonadal axis. The increasing knowledge on the mechanisms controlling the development and the function of GnRH-producing neurons is leading to a better diagnostic and therapeutic approach for hypogonadotropic hypogonadisms and for alterations of the puberty onset. During female life span, the function of the GnRH pulse generator may be affected by a number of inputs from other neuronal systems, offering alternative strategies for diagnostic and therapeutic interventions. Moreover, the identification of a GnRH/GnRH receptor system in both human ovary and endometrium has widened the spectrum of action of the peptide outside its hypothalamic functions. The pharmacological use of GnRH itself or its synthetic analogs (agonists and antagonists) provides a valid tool to either stimulate or block gonadotropin secretion and to modulate the female fertility in several reproductive disorders and in assisted reproduction technology. The use of GnRH agonists in young female patients undergoing chemotherapy is also considered a promising therapeutic approach to counteract iatrogenic ovarian failure.

Gonadotropin-releasing hormone agonists for ovarian protection during cancer chemotherapy: systematic review and meta-analysis

OBJECTIVE

To evaluate the effectiveness of gonadotropin-releasing hormone agonist (GnRHa) administration before and/or during cancer chemotherapy for the protection of ovarian reserve in premenopausal women without prior diagnosis of infertility.

METHODS

This was a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing administration of GnRHa before and/or during chemotherapy vs chemotherapy alone. Eligible participants were premenopausal women at any stage of cancer, without previous diagnosis of infertility. An electronic database search in MEDLINE, CENTRAL, LILACS and ClinicalTrials.gov was performed. After selecting eligible studies, the relative risk (RR) was assessed for primary ovarian insufficiency (POI)/amenorrhea and for spontaneous pregnancy after completion of treatment.

RESULTS

Thirteen RCTs comparing concurrent use of GnRHa and chemotherapy (609 participants) with chemotherapy alone (599 participants) were eligible for meta-analysis. All trials were open-label and patients had been treated for breast cancer (n = 1099) or lymphoma (n = 109). GnRHa had a significant benefit on the risk of POI/amenorrhea (RR, 0.60; 95% CI, 0.45-0.79), which persisted in subgroup analysis for breast cancer (RR, 0.57; 95% CI, 0.43-0.77) but not for lymphoma patients (RR, 0.70; 95% CI, 0.20-2.47). The rate of spontaneous pregnancy after completion of treatment was higher in women receiving GnRHa plus chemotherapy compared with those receiving chemotherapy alone (RR, 1.43; 95% CI, 1.01-2.02). Overall, the quality of evidence was low due to the unclear risk of bias, short follow-up and lack of objective assessment of ovarian function and reserve.

CONCLUSIONS

Evidence, albeit of low quality, supports the use of GnRHa before and/or during chemotherapy to reduce the risk of POI and increase the probability of spontaneous pregnancy in the short term. Further high quality RCTs with more accurate assessment of ovarian reserve are needed to support definitive recommendations for clinical practice. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Preservation of gonadal function in women undergoing chemotherapy: a review of the potential role for gonadotropin-releasing hormone agonists

A cancer diagnosis in women of reproductive age has unique medical and psychosocial ramifications, especially with treatments that are known to cause gonadal toxicity. For patients who undergo chemotherapy, a multidisciplinary team approach is essential to ensure that the patients' reproductive wishes are addressed. Currently, embryo and oocyte cryopreservation are the standard of care for those who wish to preserve their fertility. The use of gonadotropin-releasing hormone agonists has been a source of debate with numerous studies that have investigated the efficacy on both fertility and ovarian function preservation. This review evaluates the current literature on the use of gonadotropin-releasing hormone agonists for preservation of gonadal function. Assisted reproductive technology is excellent for preservation of fertility but will not protect gonadal function. Protection of gonadal function is critical for the broader issues of health and quality of life as a result of a hypogonadal state. At this moment, gonadotropin-releasing hormone agonists are the only drug class available to protect gonadal function.

Gonadotropin-Releasing Hormone Agonists for Ovarian Function Preservation in Premenopausal Women Undergoing Chemotherapy for Early-Stage Breast Cancer: A Systematic Review and Meta-analysis

IMPORTANCE

Chemotherapy may result in a detrimental effect on ovarian function and fertility in premenopausal women undergoing treatment for early-stage breast cancer (EBC). To minimize risk of harm to ovarian function and fertility for patients in this setting, careful considerations should be made. Gonadotropin-releasing hormone agonists (GnRHa) have been suggested as an alternative to prevent the loss of ovarian function due to exposure to cytotoxic agents, but GnRHa use for ovarian protection in EBC patients is not fully resolved.

OBJECTIVE

To determine the effectiveness of GnRHa administered concurrently with chemotherapy for ovarian function preservation.

DATA SOURCES

PubMed, SCOPUS, and Cochrane databases were searched for studies published between January 1975 and March 2015. The abstracts of the American Society of Clinical Oncology Annual Meeting between 1995 and 2014 and the San Antonio Breast Cancer Symposium between 2009 and 2014 were searched as well.

STUDY SELECTION

Prospective, randomized, clinical trials addressing the role of ovarian suppression with GnRHa in preventing early ovarian dysfunction in premenopausal women undergoing treatment for EBC were selected.

DATA EXTRACTION AND SYNTHESIS

Data extraction was performed independently by 2 authors. The methodology and the risk of bias were assessment based on the description of randomization method, withdrawals, and blinding process.

MAIN OUTCOMES AND MEASURES

Rate of resumption of regular menses after a minimal follow-up period of 6 months following chemotherapy was used as a surrogate to assess the incidence of ovarian dysfunction. Additional secondary outcomes included hormone levels and number of pregnancies. Risk ratio estimates were calculated based on the number of evaluable patients. Analyses were conducted using a random effect model.

RESULTS

Seven studies were included in this analysis, totaling 1047 randomized patients and 856 evaluable patients. The use of GnRHa was associated with a higher rate of recovery of regular menses after 6 months (odds ratio [OR], 2.41; 95% CI, 1.40-4.15; P = .002) and at least 12 months (OR, 1.85; 95% CI, 1.33-2.59; P < .001) following the last chemotherapy cycle. The use of GnRHa was also associated with a higher number of pregnancies (OR, 1.85; 95% CI, 1.02-3.36; P = .04), although this outcome was not uniformly reported and fertility or rate of pregnancy was not the primary outcome in any of the trials.

CONCLUSIONS AND RELEVANCE

Gonadotropin-releasing hormone agonists given with chemotherapy was associated with increased rates of recovery of regular menses in this meta-analysis. Evidence was insufficient to assess outcomes related to GnRHa and ovarian function and fertility and needs further investigation.

Cancer and fertility preservation: international recommendations from an expert meeting

In the last years, thanks to the improvement in the prognosis of cancer patients, a growing attention has been given to the fertility issues. International guidelines on fertility preservation in cancer patients recommend that physicians discuss, as early as possible, with all patients of reproductive age their risk of infertility from the disease and/or treatment and their interest in having children after cancer, and help with informed fertility preservation decisions. As recommended by the American Society of Clinical Oncology and the European Society for Medical Oncology, sperm cryopreservation and embryo/oocyte cryopreservation are standard strategies for fertility preservations in male and female patients, respectively; other strategies (e.g. pharmacological protection of the gonads and gonadal tissue cryopreservation) are considered experimental techniques. However, since then, new data have become available, and several issues in this field are still controversial and should be addressed by both patients and their treating physicians.In April 2015, physicians with expertise in the field of fertility preservation in cancer patients from several European countries were invited in Genova (Italy) to participate in a workshop on the topic of "cancer and fertility preservation". A total of ten controversial issues were discussed at the conference. Experts were asked to present an up-to-date review of the literature published on these topics and the presentation of own unpublished data was encouraged. On the basis of the data presented, as well as the expertise of the invited speakers, a total of ten recommendations were discussed and prepared with the aim to help physicians in counseling their young patients interested in fertility preservation.Although there is a great interest in this field, due to the lack of large prospective cohort studies and randomized trials on these topics, the level of evidence is not higher than 3 for most of the recommendations highlighting the need of further research efforts in many areas of this field. The participation to the ongoing registries and prospective studies is crucial to acquire more robust information in order to provide evidence-based recommendations.

GnRH and GnRH receptors in the pathophysiology of the human female reproductive system

BACKGROUND

Human reproduction depends on an intact hypothalamic-pituitary-gonadal (HPG) axis. Hypothalamic gonadotrophin-releasing hormone (GnRH) has been recognized, since its identification in 1971, as the central regulator of the production and release of the pituitary gonadotrophins that, in turn, regulate the gonadal functions and the production of sex steroids. The characteristic peculiar development, distribution and episodic activity of GnRH-producing neurons have solicited an interdisciplinary interest on the etiopathogenesis of several reproductive diseases. The more recent identification of a GnRH/GnRH receptor (GnRHR) system in both the human endometrium and ovary has widened the spectrum of action of the peptide and of its analogues beyond its hypothalamic function.

METHODS

An analysis of research and review articles published in international journals until June 2015 has been carried out to comprehensively summarize both the well established and the most recent knowledge on the physiopathology of the GnRH system in the central and peripheral control of female reproductive functions and diseases.

RESULTS

This review focuses on the role of GnRH neurons in the control of the reproductive axis. New knowledge is accumulating on the genetic programme that drives GnRH neuron development to ameliorate the diagnosis and treatment of GnRH deficiency and consequent delayed or absent puberty. Moreover, a better understanding of the mechanisms controlling the episodic release of GnRH during the onset of puberty and the ovulatory cycle has enabled the pharmacological use of GnRH itself or its synthetic analogues (agonists and antagonists) to either stimulate or to block the gonadotrophin secretion and modulate the functions of the reproductive axis in several reproductive diseases and in assisted reproduction technology. Several inputs from other neuronal populations, as well as metabolic, somatic and age-related signals, may greatly affect the functions of the GnRH pulse generator during the female lifespan; their modulation may offer new possible strategies for diagnostic and therapeutic interventions. A GnRH/GnRHR system is also expressed in female reproductive tissues (e.g. endometrium and ovary), both in normal and pathological conditions. The expression of this system in the human endometrium and ovary supports its physiological regulatory role in the processes of trophoblast invasion of the maternal endometrium and embryo implantation as well as of follicular development and corpus luteum functions. The GnRH/GnRHR system that is expressed in diseased tissues of the female reproductive tract (both benign and malignant) is at present considered an effective molecular target for the development of novel therapeutic approaches for these pathologies. GnRH agonists are also considered as a promising therapeutic approach to counteract ovarian failure in young female patients undergoing chemotherapy.

CONCLUSIONS

Increasing knowledge about the regulation of GnRH pulsatile release, as well as the therapeutic use of its analogues, offers interesting new perspectives in the diagnosis, treatment and outcome of female reproductive disorders, including tumoral and iatrogenic diseases.

Utility of gonadotropin-releasing hormone agonists for prevention of chemotherapy-induced ovarian damage in premenopausal women with breast cancer: a systematic review and meta-analysis

Background

Premature ovarian failure and infertility following chemotherapy are major concerns for premenopausal women with breast cancer. A potential ovarian function preservation strategy is administration of gonadotropin-releasing hormone (GnRH) agonists during adjuvant chemotherapy; however, studies of the clinical efficacy of GnRH agonists to protect chemotherapy-induced ovarian damage have shown mixed results.

Objective

This meta-analysis study was designed to estimate the efficacy of GnRH agonists administered concurrently with chemotherapy to prevent chemotherapy-induced ovarian damage in premenopausal women with breast cancer.

Methods

Electronic literature databases (PubMed, EMBASE, MEDLINE, Cochrane Library databases searching, China National Knowledge Infrastructure, Web of Science, and the Wanfang Data) were searched for relevant randomized controlled trials (RCTs) published until September 2015. Only RCTs that examined the effect of GnRH agonists for chemotherapy-induced ovarian failure in premenopausal women with breast cancer were selected. The rate of spontaneous resumption of menses and spontaneous pregnancy were collected. All data were analyzed by RevMan 5.3 (Cochrane Collaboration, Copenhagen, Denmark) and Stata 12.0 (StataCorp, College Station, TX, USA).

Results

Eleven RCTs with a total of 1,062 participants (GnRH agonists administered concurrently with chemotherapy, n=541; chemotherapy alone, n=521) were included in the meta-analysis. A significantly greater number of women treated with GnRH agonist experienced spontaneous resumption of menses after the adjuvant chemotherapy, yielding a pooled odds ratio of 2.57 (versus chemotherapy alone, 95% confidence interval (CI)=1.65, 4.01; P<0.0001). A subgroup analysis showed that addition of GnRH agonists significantly improved the resumption of menses rate in patients who were hormone-insensitive. However, the two treatment groups experienced similar spontaneous pregnancy (odds ratio =0.177; 95% CI=0.92, 1.40; P=0.09).

Conclusion

GnRH agonists cotreatment with chemotherapy in premenopausal women with breast cancer plays a beneficial role in resumption of ovarian function, with a higher rate of resumption of menses. However, treatment with GnRH agonists does not appear to exhibit its protective effects in fertility.

Current medical treatment of estrogen receptor-positive breast cancer

Approximately 80% of breast cancers (BC) are estrogen receptor (ER)-positive and thus endocrine therapy (ET) should be considered complementary to surgery in the majority of patients. The advantages of oophorectomy, adrenalectomy and hypophysectomy in women with advanced BC have been demonstrated many years ago, and currently ET consist of (1) ovarian function suppression (OFS), usually obtained using gonadotropin-releasing hormone agonists (GnRHa); (2) selective estrogen receptor modulators or down-regulators (SERMs or SERDs); and (3) aromatase inhibitors (AIs), or a combination of two or more drugs. For patients aged less than 50 years and ER+ BC, there is no conclusive evidence that the combination of OFS and SERMs (i.e., tamoxifen) or chemotherapy is superior to OFS alone. Tamoxifen users exhibit a reduced risk of BC, both invasive and in situ, especially during the first 5 years of therapy, and extending the treatment to 10 years further reduced the risk of recurrences. SERDs (i.e., fulvestrant) are especially useful in the neoadjuvant treatment of advanced BC, alone or in combination with either cytotoxic agents or AIs. There are two types of AIs: type I are permanent steroidal inhibitors of aromatase, while type II are reversible nonsteroidal inhibitors. Several studies demonstrated the superiority of the third-generation AIs (i.e., anastrozole and letrozole) compared with tamoxifen, and adjuvant therapy with AIs reduces the recurrence risk especially in patients with advanced BC. Unfortunately, some cancers are or became ET-resistant, and thus other drugs have been suggested in combination with SERMs or AIs, including cyclin-dependent kinase 4/6 inhibitors (palbociclib) and mammalian target of rapamycin (mTOR) inhibitors, such as everolimus. Further studies are required to confirm their real usefulness.

Challenges and Potential for Ovarian Preservation with SERMs

Tamoxifen (TAM) is a selective estrogen receptor modulator with tissue-specific effects on estrogen signaling used predominantly for treatment and chemoprevention of breast cancers. Recent studies have shown that TAM prevents infertility and decreases follicular loss from common cancer chemotherapy and radiation therapy in preclinical models. Here we review current and novel uses of selective estrogen receptor modulator s and advantages and challenges for translation of TAM for human fertility preservation.