Background Sperm quality at cancer diagnosis is often compromised by the disease and any given gonadotoxic treatment will further diminish fertility. Objectives Here, we aim to analyze the cryopreserved sperm quality according to the cancer types as well as the fertility outcomes. Methods Our study included all cancer patients who cryopreserved sperm over 20 years at Erasme Hospital Brussels (from 1999 to 2019). First sperm samples from 111 hematologic, 104 testicular, 19 prostate, 28 gastrointestinal, and 16 neurological cancer patients were compared. Results Oligozoo‐asthenozoospermia was observed in 30% of the samples, including 19.33% with severe oligozoospermia (<5 million/ml). Our results showed a significant reduction in sperm concentration among testicular cancer (p < 0.01). No significant differences in progressive motility, sperm volume, and number of frozen straws were observed. Significant correlations were found between sperm concentration and cancer type (p <0.01) as well as patients' age (p <0.01). Twenty‐eight cancer survivors returned for using their cryopreserved sperm (9.33%), fertilization rate was 60.5% and implantation rate was 29.6%. There was no correlation between sperm concentration and fertility outcomes. Conclusion Our results confirm the negative impact of cancer on sperm quality without affecting assisted reproductive technology (ART) success rate, which is utterly important as a male reproductive health perspective. All cancer patients should be counselled and offered fertility preservation options as a gold standard.

Study question Does first-line chemotherapy prior to ovarian tissue cryopreservation and diseases impact on the signaling pathways governing follicle activation and survival in pre-pubertal and adult patients? Summary answer Chemotherapy increases follicle apoptosis rate without affecting early follicular activation. Moreover, damages varied according to the time of last exposure and the diseases. What is known already Chemotherapeutic agents can impair the ovarian stockpile inducing a decrease of the reproductive potential of female cancer survivors. Among fertility preservation methods, cortical tissue cryopreservation is offered in patients who already started their treatment or cannot postpone it, and it is currently the only available procedure for pre-pubertal patients. Few studies did not report negative impact of prior first-line chemotherapy on ovarian tissue cryopreservation outcomes, the consequences of the treatment on the follicle activation in human remain to be further investigated. Identifying the signaling modifications induced by chemotherapy exposure is essential to address this question. Study design, size, duration Fragments of cryopreserved ovarian tissue from young adult (12-29 years old, n = 8) and pre-pubertal (3-10 years old, n = 7) cancer patients donated for research were thawed and cultured for 24h. Analyses of the follicle and stroma survival, as well as the PI3K/AKT/mTOR and Hippo signaling pathways were conducted at thawing and after culture. The different patients were grouped according to their pubertal stage and those who received chemotherapy before ovarian banking were compared to non-exposed patients. Participants/materials, setting, methods To assess the distribution and morphology of the follicles, the structure of the stroma, and the apoptosis, histological investigations were performed through follicular counting, Sirius Red staining, immunostaining, and TUNEL staining. The PI3K/AKT/mTOR and Hippo signaling pathways were investigated to explore the follicular activation among the different groups by gene expression and protein analyses on isolated follicles and cortex, respectively. Main results and the role of chance The deleterious impact of chemotherapy exposure prior to tissue banking was observed specifically on quiescent follicles by TUNEL staining at thawing and after culture in both adult and pre-pubertal patients. After 24h of culture, tissues previously exposed to chemotherapy displayed a higher rate of follicles containing DNA damages than the non-exposed fragments in adults (40.9% versus 19.1%), and pre-pubertal (48.3% versus 17.6%) patients. The atresia rates and DNA damages appeared to be lower into the tissue of patients that received their last cure 4-5 months before the cryopreservation among the treated adult and pre-pubertal groups. DNA reparation mechanisms were assessed through gH2Ax staining and revealed a correlation with the diseases as a higher phosphorylation rate of H2Ax protein was observed in tissues from acute leukemia patients compare to the others at thawing (p = 0.009) and after 24h (p < 0.001). Although protein analyses on Kit Ligand, key regulator of the follicle activation, showed an increase of expression into the groups treated by chemotherapy, genes and protein involved in the PI3K/AKT/mTOR and Hippo pathways showed similar expression levels in the chemo-treated groups compared to the non-exposed groups, irrespective of the age. Limitations, reasons for caution The study of follicle survival was limited to histological analyses, while follicular activation evaluations were limited to the evaluation of two main signaling, PI3K/AKT/mTOR and Hippo. Moreover, considering the heterogeneity of the human model, and the limited number of patients included, the results should be interpreted with caution. Wider implications of the findings Our results highlight the deleterious impact of previous chemotherapeutic treatment on follicle survival without affecting follicular activation. Besides sustaining the “burn out effect” theory, our results suggested that the time of last exposure and the pathology of the patient could impact the outcomes of the cryopreserved ovarian tissue. Trial registration number not applicable

More than 10% of women diagnosed with breast cancer during reproductive age carry hereditary germline pathogenic variants in high-penetrance BRCA genes or in others genes involved in DNA repair mechanisms such as PALB2, BRIP or ATM. Anticancer treatments may have an additional negative impact on the ovarian reserve and subsequently on the fertility of young patients carrying such mutations. Recently, the combination of carboplatin and paclitaxel is being recommended to these BRCA-mutated patients as neoadjuvant therapy. However, the impact on the ovary is unknown. Here, we investigated their effect of on the ovarian reserve using mice carriers of BRCA1-interacting protein C-terminal helicase-1 (BRIP1) mutation that plays an important role in BRCA1-dependent DNA repair. Results revealed that the administration of carboplatin or paclitaxel did not affect the ovarian reserve although increased DNA double-strand breaks were observed with carboplatin alone. Co-administration of carboplatin and paclitaxel resulted in a significant reduction of the ovarian reserve leading to a lower IVF performance, and an activation of the PI3K-Pten pathway, irrespective of the genetic background. This study suggests that co-administration of carboplatin and paclitaxel induces cumulative ovarian damage and infertility but a heterozygote genetic predisposition for DNA damage related to BRCA1 gene function does not increase this risk. Breast cancer is the most common cancer type in young adults worldwide, with the breast cancer global incidence in 20-39-year-old females at 17.0 per 100,000 people per year 1. Germline pathogenic variants in the breast cancer susceptibility genes BRCA1 and BRCA2 account for about 12% of the cases 2. Other germline mutations in genes involved in DNA repair such as RAD51, PALB2 or BRIP confer cancer susceptibility, highlighting their crucial role in maintaining genome integrity. For these patients, fertility issues may be of particular concern as previous studies suggested a possible negative impact of BRCA pathogenic variants on ovarian reserve and fertility 3,4. BRCA is known to be involved in homologous DNA recombination, and plays an essential role in DNA double-strand breaks (DSBs) repair protecting the integrity of the genome in proliferating cells. Pathogenic variants in BRCA genes, and especially in BRCA1, result in deficient homologous-recombination DNA repair and chromosomal instability. Besides the high risk of developing breast and ovarian cancers, deficient DNA repair in BRCA-mutated patients may leave oocytes more prone to DNA damage and aging resulting in diminished ovarian reserve 5,6. Major advances in anticancer therapies have contributed to increase the survival rate over the last years. However, these treatments may have some long-term side effects including a negative impact on ovarian germ cells that may lead to premature ovarian insufficiency (POI) and subsequent infertility 7,8. The negative impact on the ovarian reserve could be even more of concern in BRCA-mutated breast cancer patients. The investigation of the gonadotoxic burden of new anticancer therapies is a research priority, especially for patients harbouring BRCA pathogenic variants 9,10 , considering that this knowledge is a prerequisite to offer adequate fertility preservation counselling.

Background: New therapeutic approaches in oncology have converted cancer from a certain death sentence to a chronic disease. However, there are still challenges to be overcome regarding the off-target toxicity of many of these treatments. Oncological therapies can lead to future infertility in women. Given this negative impact on long-term quality of life, fertility preservation is highly recommended. While gamete and ovarian tissue cryopreservation are the usual methods offered, new pharmacological-based options aiming to reduce ovarian damage during oncological treatment are very attractive. In this vein, advances in the field of transcriptomics and epigenomics have brought small noncoding RNAs, called microRNAs (miRNAs), into the spotlight in oncology. MicroRNAs also play a key role in follicle development as regulators of follicular growth, atresia and steroidogenesis. They are also involved in DNA damage repair responses and they can themselves be modulated during chemotherapy. For these reasons, miRNAs may be an interesting target to develop new protective therapies during oncological treatment. This review summarizes the physiological role of miRNAs in reproduction. Considering recently developed strategies based on miRNA therapy in oncology, we highlight their potential interest as a target in fertility preservation and propose future strategies to make the transition from bench to clinic. Objective and rationale: How can miRNA therapeutic approaches be used to develop new adjuvant protective therapies to reduce the ovarian damage caused by cytotoxic oncological treatments? Search methods: A systematic search of English language literature using PubMed and Google Scholar databases was performed through to 2019 describing the role of miRNAs in the ovary and their use for diagnosis and targeted therapy in oncology. Personal data illustrate miRNA therapeutic strategies to target the gonads and reduce chemotherapy-induced follicular damage. Outcomes: This review outlines the importance of miRNAs as gene regulators and emphasizes the fact that insights in oncology can inspire new adjuvant strategies in the field of onco-fertility. Recent improvements in nanotechnology offer the opportunity for drug development using next-generation miRNA-nanocarriers. Wider implications: Although there are still some barriers regarding the immunogenicity and toxicity of these treatments and there is still room for improvement concerning the specific delivery of miRNAs into the ovaries, we believe that, in the future, miRNAs can be developed as powerful and non-invasive tools for fertility preservation.