Perinatal outcomes of pregnancies following autologous cryopreserved ovarian tissue transplantation: a systematic review with pooled analysis.

OBJECTIVE: This study aimed to synthesize the existing evidence on perinatal outcomes after autologous cryopreserved ovarian tissue transplantation, concurrently identifying key factors influencing these outcomes. DATA SOURCES: A comprehensive search was performed on MEDLINE, Embase, and Cochrane Library databases to identify relevant studies on the effect of autologous cryopreserved ovarian tissue transplantation on perinatal outcomes from inception to October 22, 2023. Where there was missing information, the authors were contacted for updated data. STUDY ELIGIBILITY CRITERIA: Observational studies, such as cohort studies, case series, and case reports that reported a live birth after autologous cryopreserved ovarian tissue transplantation, were considered eligible. Studies lacking data on women's demographic characteristics, autologous cryopreserved ovarian tissue transplantation procedure details, or perinatal outcomes were excluded. In addition, cases involving fresh or nonautologous transplantations and those addressing primary ovarian insufficiency were excluded. METHODS: Two reviewers (M.E. and E.U.) independently performed the study selection, data extraction, and risk of bias assessment, and the results were then reviewed together. The PRISMA guidelines were followed, and the protocol was registered on PROSPERO (CRD42023469296). RESULTS: This review included 58 studies composed of 122 women with 162 deliveries (154 singletons and 8 twins) after autologous cryopreserved ovarian tissue transplantation, resulting in 170 newborns. Of note, 83.6% of the women had a malignant disease. Moreover, most of these women (51.0%) were exposed to some form of chemotherapy before ovarian tissue cryopreservation. Of the 162 childbirths, 108 (66.7%) were conceived naturally, and 54 (33.3%) were conceived through assisted reproductive techniques. The birthweight of 88.5% of newborns was appropriate for gestational age, whereas 8.3% and 3.1% were small for gestational age and large for gestational age, respectively. The preterm birth rate was 9.4%, with the remaining being term deliveries. Hypertensive disorders of pregnancy were noted in 18.9% of women, including pregnancy-induced hypertension in 7.6%, preeclampsia in 9.4%, and hemolysis, elevated liver enzymes, and low platelet count in 1.9%. The incidences of gestational diabetes mellitus and preterm premature rupture of membranes were 3.8% for each condition. Neonatal anomalies were reported in 3 transplant recipients with 4 newborns: arthrogryposis, congenital cataract, and diaphragmatic hernia in a twin. Finally, among the recipients' characteristics, not receiving chemotherapy before ovarian tissue cryopreservation (odds ratio, 0.23; 95% confidence interval, 0.07-0.72; P=.012) and natural conception (odds ratio, 0.29; 95% confidence interval, 0.09-0.92; P=.035) were associated with a lower perinatal complication rate. CONCLUSION: On the basis of low certainty evidence from observational studies, perinatal complication rates did not increase after autologous cryopreserved ovarian tissue transplantation compared with the general pregnant population, except for preeclampsia. This could be due to chemotherapy exposure, underlying medical conditions, and the common use of assisted reproductive techniques. Further larger studies are needed to explore the causes of increased preeclampsia incidence in autologous cryopreserved ovarian tissue transplantation pregnancies.

A Journey to Reach the Ovary Using Next-Generation Technologies.

Although effective in terms of the chances of future live birth, the current methods for fertility preservation, such as oocyte, embryo, or ovarian tissue cryopreservation, cannot be offered to all cancer patients in all clinical contexts. Expanding options for fertility preservation is crucial to addressing the need to encompass all situations. One emerging strategy is pharmacoprotection, a non-invasive approach that has the potential to fill existing gaps in fertility preservation. In addition to the identification of the most effective therapeutic agents, the potential for off-target effects remains one of the main limitations of this strategy for clinical application, particularly when healthy ovarian tissue is targeted. This review focuses on the advances in pharmacoprotective approaches and the challenge of targeting the ovaries to deliver these agents. The unique properties of gold nanoparticles (AuNPs) make them an attractive candidate for this purpose. We discuss how AuNPs meet many of the requirements for an ideal drug delivery system, as well as the existing limitations that have hindered the progression of AuNP research into more clinical trials. Additionally, the review highlights microRNA (miRNA) therapy as a next-generation approach to address the issues of fertility preservation and discusses the obstacles that currently impede its clinical availability.

The Role of Cyclin-Dependent Kinases (CDK) 4/6 in the Ovarian Tissue and the Possible Effects of Their Exogenous Inhibition.

The combination of cyclin-dependent kinase (CDK) 4/6 inhibitors with endocrine therapy is the standard treatment for patients with HR+/HER2- advanced breast cancer. Recently, this combination has also entered the early setting as an adjuvant treatment in patients with HR+/HER2- disease at a high risk of disease recurrence following (neo)adjuvant chemotherapy. Despite their current use in clinical practice, limited data on the potential gonadotoxicity of CDK4/6 inhibitors are available. Hence, fully informed treatment decision making by premenopausal patients concerned about the potential development of premature ovarian insufficiency and infertility with the proposed therapy remains difficult. The cell cycle progression of granulosa and cumulus cells is a critical process for ovarian function, especially for ensuring proper follicular growth and acquiring competence. Due to the pharmacological properties of CDK4/6 inhibitors, there could be a potentially negative impact on ovarian function and fertility in women of reproductive age. This review aims to summarize the role of the cyclin D-CDK4 and CDK6 complexes in the ovary and the potential impact of CDK4/6 inhibition on its physiological processes.

Regulation of follicular activation signaling pathways by in vitro inhibition of YAP/TAZ activity in mouse ovaries.

The Hippo pathway plays a crucial role in the regulation of follicular activation, which constitutes the first step of the folliculogenesis process. Disruption of this pathway occurs in several non-physiological contexts, after fragmentation for ovarian tissue cryopreservation procedures or chemotherapy exposure, leading to massive follicular growth and depletion. This study aimed to investigate the effect of controlling the Hippo pathway using verteporfin (VERT) during in vitro ovarian culture and to evaluate its potential preventive effects on chemotherapy-induced follicle activation using a mouse model. After exposure of cut ovaries to different concentrations of VERT for 3 h, a dose-dependent effect of VERT was observed that reached significant inhibition of YAP activity at 3 µmol/L. To assess the potential effect of controlling chemotherapy-induced Hippo pathway disruption, whole mouse ovaries were exposed to VERT alone or as a co-treatment with 4-hydroperoxycylophosphamide (4HC). VERT co-treatment prevented chemotherapy-induced YAP activation but had a limited impact on downstream effector gene, Ccn2. Surprisingly, VERT co-treatment also prevented mTOR and survival signaling pathway alterations following chemotherapy exposure. These results suggest an interaction between the two main signaling pathways regulating follicle activation and a protective effect of VERT on 4HC-induced DNA damage.

Impact of Breast Cancer and Germline BRCA Pathogenic Variants on Fertility Preservation in Young Women.

BACKGROUND: Several studies have suggested that breast cancer (BC) and germline BRCA pathogenic variants (gBRCA PVs) could have a deleterious impact on ovarian reserve. Nevertheless, data are limited and mixed. Our objective was to evaluate the performance of fertility preservation (FP) in terms of the number of collected mature oocytes after ovarian stimulation (OS) in young women carrying a gBRCA PV, associated or not with BC. METHODS: We conducted a retrospective monocentric study at HUB-Hôpital Erasme in Brussels. All women aged between 18 and 41 years diagnosed with invasive non-metastatic BC and/or gBRCA PV carriers who underwent OS for FP or preimplantation genetic testing for monogenic disorder (PGT-M) between November 2012 and October 2021 were included. Three groups were compared: BC patients without a gBRCA PV, BC patients with a gBRCA PV, and healthy gBRCA PV carriers. Ovarian reserve was evaluated based on the efficacy of OS and AMH levels. RESULTS: A total of 85 patients underwent 100 cycles. The mean age (32.2 ± 3.9 years; p = 0.61) and median AMH level (1.9 [0.2-13] µg/L; p = 0.22) were similar between groups. Correlations between the number of mature oocytes and AMH level (p < 0.001) and between AMH and age (p < 0.001) were observed. No differences in the number of retrieved mature oocytes were observed between groups (p = 0.41), or for other OS parameters. CONCLUSION: Neither BC nor a gBRCA PV significantly affects ovarian reserve and FP efficacy in terms of the number of mature oocytes retrieved.

Gene Expression Analyses in Human Follicles.

The ovary is a heterogeneous organ composed of different cell types. To study the molecular mechanisms occurring during folliculogenesis, the localization of proteins and gene expression can be performed on fixed tissue. However, to properly assess gene expression levels in a human follicle, this complex and delicate structure must be isolated. Hence, an adapted protocol previously described by Woodruff's laboratory has been developed to separate follicles (the oocyte and the granulosa cells) from their surrounding environment. The ovarian cortical tissue is first manually processed to obtain small fragments using two tools: a tissue slicer and a tissue chopper. The tissue is then enzymatically digested with 0.2% collagenase and 0.02% DNase for at least 40 min. This digestion step is performed at 37 °C and 5% CO2 and is accompanied by mechanical pipetting of the medium every 10 min. After incubation, the isolated follicles are collected manually using a calibrated microcapillary pipette under microscope magnification. If follicles are still present in the pieces of tissue, the procedure is completed with manual microdissection. The follicles are collected on ice in a culture medium and are rinsed twice in droplets of phosphate-buffered saline solution. This digestion procedure must be carefully controlled to avoid follicle deterioration. As soon as the structure of the follicles appears to be compromised or after a maximum of 90 min, the reaction is stopped with a 4 °C blocking solution containing 10% fetal bovine serum. A minimum of 20 isolated follicles (sized under 75 µm) should be collected to obtain an adequate amount of total RNA after RNA extraction for real-time quantitative polymerase chain reaction (RT-qPCR). After extraction, the quantification of total RNA from 20 follicles reaches a mean value of 5 ng/µL. The total RNA is then retrotranscribed into cDNA, and the genes of interest are further analyzed using RT-qPCR.

Impact of first chemotherapy exposure on follicle activation and survival in human cryopreserved ovarian tissue.

STUDY QUESTION: Does chemotherapy exposure prior to ovarian tissue cryopreservation (OTC) impact the signaling pathways governing follicle activation and survival for prepubertal and postpubertal patients? SUMMARY ANSWER: Chemotherapy exposure prior OTC increases follicle apoptosis rates but not follicular activation, although the PI3K/AKT/mTOR and Hippo signaling pathways were modified in the cortex. WHAT IS KNOWN ALREADY: OTC is currently the only available fertility preservation procedure for children and for patients who have already started their treatment. While previous studies have not observed harmful impacts of first chemotherapy exposure on OTC outcomes, the consequences of treatment on follicle activation and survival need to be further investigated. To address this question, we evaluated signaling pathway modifications induced by chemotherapy exposure according to pubertal status. STUDY DESIGN, SIZE, DURATION: Cryopreserved ovarian tissues from postpubertal (12-29 years old, n = 8) and prepubertal (3-10 years old, n = 8) cancer patients donated for research were thawed and cultured for 24 h. Analyses of the survival of the follicles and stroma, and of the PI3K/AKT/mTOR and Hippo signaling pathways, were conducted at thawing and after culture. Ovarian fragments exposed to chemotherapy before collection were compared to non-exposed controls. PARTICIPANTS/MATERIALS, SETTING, METHODS: Histological investigations were performed to assess the distribution of the follicles, stroma fibrosis, vessel integrity, and apoptosis levels. It included follicular counting, collagen staining, immunostaining on CD31 and gH2AX, as well as TUNEL staining. To explore follicle activation in the different groups, the PI3K/AKT/mTOR and Hippo signaling pathways were investigated by gene expression analyses of isolated follicles and protein analyses on whole fragments through western blots and immunostaining. MAIN RESULTS AND THE ROLE OF CHANCE: We first assessed the impact of a first exposure to chemotherapy on the collagen density and vessels in ovarian tissues at thawing and after culture. While no differences in collagen density were observed according to age or previous treatment, the vascularization area (CD31+) was significantly lower in tissue from previously exposed patients compared to non-treated ones. Apoptosis analyses (TUNEL) revealed an acute deleterious impact on follicle survival after chemotherapy exposure without affecting the follicular density. Surprisingly, leukemic patients had a significantly higher percentage of gH2AX-positive follicles, indicating a DNA damage response, compared to the other patients. The proportion of activated follicles appeared to decrease following exposure to chemotherapy, suggesting that it at least did not increase activation process. Stable KIT LIGAND gene and protein expression and cKIT protein levels were observed among the groups, confirming the absence of activation. Analysis of the PI3K pathway did not reveal a difference in the AKT phosphorylation level between the groups, but pRPS6 was significantly higher in tissue from patients previously exposed to chemotherapy compared to that from non-exposed patients. Finally, protein and gene analyses on Hippo pathway signaling showed a higher LATS1 protein level in the cortex after chemotherapy exposure. LIMITATIONS, REASONS FOR CAUTION: The heterogeneity of the human fragments, and the limited number of patients included in the cohort have to be considered as important study limitations. Moreover, this study did not explore the long-term consequences of chemotherapy on follicular development. Therefore, the results should be interpreted with caution. WIDER IMPLICATIONS OF THE FINDINGS: These results underscore the deleterious effect of previous chemotherapeutic treatment on follicle survival. Although follicular density was not reduced, these data suggested that exposure to chemotherapy impacts follicular apoptosis and the DNA damage response. Chemotherapy-induced activation was not observed despite the impact on mTOR and Hippo signaling pathways in the whole cortex. STUDY FUNDING/COMPETING INTEREST(S): This work was funded by an Excellence of Science (EOS) Grant (ID: 30443682) and was supported by Fonds Erasme. I.D. and M.-M.D. are associate researchers at Fonds National de la Recherche Scientifique de Belgique (FNRS). There are no competing interests. TRIAL REGISTRATION NUMBER: N/A.

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.

BRCA Mutations and Fertility Preservation.

Hereditary cancers mostly affect the adolescent and young adult population (AYA) at reproductive age. Mutations in BReast CAncer (BRCA) genes are responsible for the majority of cases of hereditary breast and ovarian cancer. BRCA1 and BRCA2 act as tumor suppressor genes as they are key regulators of DNA repair through homologous recombination. Evidence of the accumulation of DNA double-strand break has been reported in aging oocytes, while BRCA expression decreases, leading to the hypothesis that BRCA mutation may impact fertility. Moreover, patients exposed to anticancer treatments are at higher risk of fertility-related issues, and BRCA mutations could exacerbate the treatment-induced depletion of the ovarian reserve. In this review, we summarized the functions of both genes and reported the current knowledge on the impact of BRCA mutations on ovarian ageing, premature ovarian insufficiency, female fertility preservation strategies and insights about male infertility. Altogether, this review provides relevant up-to-date information on the impact of BRCA1/2 mutations on fertility. Notably, BRCA-mutated patients should be adequately counselled for fertility preservation strategies, considering their higher sensitivity to chemotherapy gonadotoxic effects.

The Role of microRNA in Spermatogenesis: Is There a Place for Fertility Preservation Innovation?

Oncological treatments have dramatically improved over the last decade, and as a result, survival rates for cancer patients have also improved. Quality of life, including concerns about fertility, has become a major focus for both oncologists and patients. While oncologic treatments are often highly effective at suppressing neoplastic growth, they are frequently associated with severe gonadotoxicity, leading to infertility. For male patients, the therapeutic option to preserve fertility is semen cryopreservation. In prepubertal patients, immature testicular tissue can be sampled and stored to allow post-cure transplantation of the tissue, immature germ cells, or in vitro spermatogenesis. However, experimental techniques have not yet been proven effective for restoring sperm production for these patients. MicroRNAs (miRNAs) have emerged as promising molecular markers and therapeutic tools in various diseases. These small regulatory RNAs possess the unique characteristic of having multiple gene targets. MiRNA-based therapeutics can, therefore, be used to modulate the expression of different genes involved in signaling pathways dysregulated by changes in the physiological environment (disease, temperature, ex vivo culture, pharmacological agents). This review discusses the possible role of miRNA as an innovative treatment option in male fertility preservation-restoration strategies and describes the diverse applications where these new therapeutic tools could serve as fertility protection agents.

Efficacy and safety of controlled ovarian hyperstimulation with or without letrozole for fertility preservation in breast cancer patients: A multicenter retrospective study.

INTRODUCTION: Fertility preservation (FP) is recommended in young breast cancer (BC) patients before (neo)adjuvant treatment. Letrozole-associated controlled ovarian hyperstimulation (LetCOH) is used worldwide to collect mature oocytes for FP, but its efficacy and safety compared to conventional protocols (cCOH) are still debated. AIMS: To compare efficacy and safety of FP procedure using LetCOH or cCOH in BC patients in terms of oocyte maturation rate and disease-free survival rates after at least two years of follow-up. METHODS: This multicenter retrospective study compared outcomes of 107 cycles in 97 non-metastatic BC patients aged ≤40 years who underwent cCOH (n = 56) or LetCOH (n = 41) for FP in CHU-Lille and Erasme Hospital, respectively, between December 2012 and January 2017. RESULTS: Patients and oncological characteristics were similar except for tumor size and HER2 status which were less favorable in the LetCOH group. Patients underwent adjuvant chemotherapy in 96.4% and 48.8% of the cases in cCOH and LetCOH groups, respectively. Hence, 51.2% of LetCOH patients underwent neoadjuvant chemotherapy (p < 0.001). Estradiol peak at ovulation trigger was lower in LetCOH compared to cCOH group while oocyte maturation rates were significantly higher (p < 0.001), without impacting the final number of mature oocytes collected. Seven and four patients relapsed in LetCOH and cCOH groups, respectively, and one patient died in each group after a median follow-up of four years. CONCLUSION: LetCOH is as effective as cCOH for FP. At this time point, there were no safety concerns regarding cCOH in the adjuvant setting but a longer follow-up is warranted.

Let-7a mimic transfection reduces chemotherapy-induced damage in a mouse ovarian transplantation model.

Pharmacological approaches offer a non-invasive and promising option for fertility preservation in young female cancer patients undergoing gonadotoxic therapy. The GnRH-agonists are the only clinically available drugs in this indication, but their use and mechanisms of protection are still controversial. Recently, we have investigated new targeted drugs based on microRNA (miRNA) replacement therapy, and have identified the let-7a miRNA as candidate for fertility preservation strategies. Here, the effect of let-7a replacement during chemotherapy exposure on follicular growth and oocyte maturation capacity was investigated using a mouse ovarian-kidney transplantation model. Newborn mouse ovaries were cultured under different conditions; control, chemotherapy exposure (4-hydroperoxycyclophosphamide, 4-HC), and co-treatment with 4-HC and let-7a mimic transfection (4-HC + let-7a). The ovaries were then transplanted under the kidney capsule of recipient mice and follicular growth, survival, and oocyte in vitro maturation were assessed after 3 weeks. The results showed that the follicular pool was highest in the control group but higher in the 4-HC + let-7a group than the 4-HC group. DNA-damage/apoptosis ratios were higher in all 4-HC-exposed groups compared to control but were reduced in the 4-HC + let-7a group. In addition, the post-transplantation oocyte in vitro maturation rate was higher in the 4-HC + let-7a group compared to the 4-HC group, suggesting better oocyte quality. These results provide new information regarding the beneficial effects of let-7a replacement against chemotherapy-induced ovarian damage and open new perspectives for future in vivo applications.

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.

Fresh and cryopreserved ovarian tissue transplantation for preserving reproductive and endocrine function: a systematic review and individual patient data meta-analysis.

BACKGROUND: Ovarian tissue cryopreservation involves freezing and storing of surgically retrieved ovarian tissue in liquid or vapour nitrogen below -190°C. The tissue can be thawed and transplanted back with the aim of restoring fertility or ovarian endocrine function. The techniques for human ovarian tissue freezing and transplantation have evolved over the last 20 years, particularly in the context of fertility preservation in pre-pubertal cancer patients. Fresh ovarian tissue transplantation, using an autograft or donor tissue, is a more recent development; it has the potential to preserve fertility and hormonal function in women who have their ovaries removed for benign gynaecological conditions. The techniques of ovarian tissue cryopreservation and transplantation have progressed rapidly since inception; however, the evidence on the success of this intervention is largely based on case reports and case series. OBJECTIVE AND RATIONALE: The aim of this study was to systematically review the current evidence by incorporating study-level and individual patient-level meta-analyses of women who received ovarian transplants, including frozen-thawed transplant, fresh or donor graft. SEARCH METHODS: The review protocol was registered with PROSPERO (CRD42018115233). A comprehensive literature search was performed using MEDLINE, EMBASE, CINAHL and Cochrane Central Register of Controlled Trials from database inception to October 2020. Authors were also contacted for individual patient data if relevant outcomes were not reported in the published manuscripts. Meta-analysis was performed using inverse-variance weighting to calculate summary estimates using a fixed-effects model. OUTCOMES: The review included 87 studies (735 women). Twenty studies reported on ≥5 cases of ovarian transplants and were included in the meta-analysis (568 women). Fertility outcomes included pregnancy, live birth and miscarriage rates, and endocrine outcomes included oestrogen, FSH and LH levels. The pooled rates were 37% (95% CI: 32-43%) for pregnancy, 28% (95% CI: 24-34%) for live birth and 37% (95% CI: 30-46%) for miscarriage following frozen ovarian tissue transplantation. Pooled mean for pre-transplant oestrogen was 101.6 pmol/l (95% CI: 47.9-155.3), which increased post-transplant to 522.4 pmol/l (95% CI: 315.4-729; mean difference: 228.24; 95% CI: 180.5-276). Pooled mean of pre-transplant FSH was 66.4 IU/l (95% CI: 52.8-84), which decreased post-transplant to 14.1 IU/l (95% CI: 10.9-17.3; mean difference 61.8; 95% CI: 57-66.6). The median time to return of FSH to a value <25 IU/l was 19 weeks (interquartile range: 15-26 weeks; range: 0.4-208 weeks). The median duration of graft function was 2.5 years (interquartile range: 1.4-3.4 years; range: 0.7-5 years). The analysis demonstrated that ovarian tissue cryopreservation and transplantation could restore reproductive and hormonal functions in women. Further studies with larger samples of well-characterized populations are required to define the optimal retrieval, cryopreservation and transplantation processes. WIDER IMPLICATIONS: Ovarian tissue cryopreservation and transplantation may not only be effective in restoring fertility but also the return of reproductive endocrine function. Although this technology was developed as a fertility preservation option, it may have the scope to be considered for endocrine function preservation.

A retrospective study evaluating the impact of scattering radiation from imaging procedures on oocyte quality during ovarian stimulation for fertility preservation in young breast cancer patients.

PURPOSE: Ovarian stimulation for oocyte and embryo cryopreservation is the standard of care for fertility preservation in young breast cancer patients before gonadotoxic chemotherapy. The procedure should be started as soon as possible to avoid delay of treatment; thus, it is often performed concomitantly with tumor staging assessments. However, questions remain regarding the potential negative impact on oocyte quality that may occur due to exposure to scattered ionizing radiation from imaging techniques when staging assessment is conducted at the same time as ovarian stimulation. METHODS: We conducted a retrospective study on all breast cancer patients who performed ovarian stimulation for fertility preservation at our center between November 2012 and May 2020. RESULTS: Gynecologic and oncological characteristics were similar between patients exposed (n = 14) or not (n = 60) to ionizing radiation. Exposed patients started the ovarian stimulation sooner after diagnosis than non-exposed patients (11.5 vs 28 days, respectively, P < 0.01). Cycle parameters, including the median number of oocytes collected (10.5 vs 7, P = 0.16), maturation rates (92.5% vs 85.7%, P = 0.54), and fertilization rates (62.2% vs 65.4%, P = 0.70), were similar between groups. CONCLUSION: This study shows that scattered ionizing radiation due to staging assessment appears to be safe without compromising follicular growth and maturation. Larger studies on fertility and obstetrical outcomes are needed to confirm these preliminary data.

Circulating Tumor DNA to Interrogate the Safety of Letrozole-Associated Controlled Ovarian Stimulation for Fertility Preservation in Breast Cancer Patients.

BACKGROUND: Current fertility preservation strategies for young breast cancer patients planning a future motherhood include the association of controlled ovarian stimulation with the aromatase inhibitor letrozole (let-COS) to harvest mature oocytes while maintaining low estradiol levels. Despite this is a widely adopted protocol, the safety of let-COS on breast cancer outcomes has been poorly investigated and its use remains off-label. We assessed the safety of let-COS in breast cancer patients using circulating tumor DNA (ctDNA) as a surrogate biomarker of disease recurrence. METHODS: BROVALE is an interventional non-randomized prospective study designed to evaluate the efficacy and safety of let-COS for fertility preservation in early breast cancer patients before starting (neo)adjuvant chemotherapy. Letrozole was administered throughout the COS cycle, until ovulation triggering. Safety was a secondary endpoint. Data on oncological outcomes were collected during the follow-up as well as plasma and whole blood for evaluation of ctDNA levels at the time of enrollment (i.e. before starting let-COS) and oocyte retrieval (i.e. 48 hours after the last administration of letrozole). Targeted gene sequencing on the primary tumor samples was performed to identify specific mutations used for ctDNA analysis by digital PCR. DNA extracted from whole blood samples was used to discriminate between somatic and germline mutations. RESULTS: From April 2014 to May 2017, 29 young early breast cancer patients enrolled in the BROVALE study who had available tissue samples participated to the ctDNA substudy. Among them, 15 had at least one validated somatic mutation. ctDNA was undetectable neither before nor after let-COS in 9 of them. Six patients had detectable ctDNA in the plasma samples collected before Let-COS. No change in ctDNA level after let-COS was observed in 3 patients and the level decreased (fold-change ≤ 0.5) in two women. One patient experienced an increased (fold-change ≥ 2) in ctDNA level but without disease relapse 34 months after diagnosis. CONCLUSIONS: No increase in ctDNA level was observed in 93% (14/15) of the patients receiving let-COS supporting its use as a safe strategy for young women with early breast cancer interested in fertility preservation before chemotherapy.