Long-term follow-up to assess criteria for ovarian tissue cryopreservation for fertility preservation in young women and girls with cancer.

STUDY QUESTION: Do the Edinburgh Selection Criteria correctly identify female cancer patients under the age of 18 who are at risk of premature ovarian insufficiency (POI) as candidates for ovarian tissue cryopreservation (OTC)? SUMMARY ANSWER: Patient assessment using these criteria accurately identifies those at risk of POI, who can be offered OTC and future transplantation as a means of fertility preservation. WHAT IS KNOWN ALREADY: Treatment for childhood cancer can have adverse consequences on future fertility; at the time of diagnosis, fertility risk assessment should be undertaken in order to identify patients to whom fertility preservation should be offered. The Edinburgh selection criteria, based on planned cancer treatment and patient health status, are utilized to identify those at high risk and therefore eligible for OTC. However, this procedure is not without risk and there are few data on the efficacy of the procedure in prepubertal patients. As such, long-term follow-up of reproductive outcomes is necessary, to ensure that OTC is being offered appropriately. STUDY DESIGN, SIZE, DURATION: Cohort study encompassing all females diagnosed with cancer under the age of 18 in South East Scotland, from 1 January 1996 to 30 April 2020. Patients were followed up for reproductive outcomes to assess for diagnosis of POI. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 638 eligible patients were identified; patients under the age of 12 or deceased before the age of 12 were excluded from the study, leaving a study population of 431 patients. Electronic records were reviewed for reproductive function, assessed by current menstruation, pregnancy (in the absence of POI diagnosis), reproductive hormone measurements, pubertal progression, or diagnosis of POI. Patients on hormonal contraception (other than for treatment of POI or panhypopituitarism with no history of gonadatoxic treatment) were excluded from analysis (n = 9). Analysis on remaining 422 patients was carried out using the Kaplan-Meier methods, with POI as the defined event, and Cox proportional hazards model. MAIN RESULTS AND THE ROLE OF CHANCE: In the study population of 431 patients, median ages at diagnosis and analysis were 9.8 and 22.2 years, respectively. Reproductive outcomes were unavailable in 142 patients; the assumption was made that these patients did not have POI, but a subanalysis excluding these patients was also performed. Of the 422 patients aged >12 at analysis and not taking hormonal contraception, OTC was offered to 37 patients and successfully performed in 25 patients. Of the 37 patients offered OTC (one at time of relapse), nine (24.3%) developed POI. Of the 386 not offered OTC, 11 (2.9%) developed POI. The probability of developing POI was significantly higher in those offered OTC (hazard ratio [HR] 8.7 [95% CI 3.6-21]; P < 0.0001), even when those patients with unknown outcomes were excluded from the analysis (HR 8.1 [95% CI 3.4-20]; P < 0.001). All patients offered OTC who developed POI did so after treatment for primary disease; in those not offered OTC, five patients (45.5%) developed POI after treatment for disease relapse. LIMITATIONS, REASONS FOR CAUTION: A significant number of patients had unknown reproductive outcomes; many of these patients were engaged in ongoing follow-up but did not have documented reproductive assessment. This may have introduced bias to the analysis and highlights the need for reproductive follow-up as part of routine cancer aftercare. In addition, the relatively young age of the patient population and short duration of follow-up in some cases demonstrates the need for ongoing follow-up of this cohort. WIDER IMPLICATIONS OF THE FINDINGS: The prevalence of POI after childhood cancer is low, but the Edinburgh selection criteria remain a robust tool for selecting those at high risk at the time of diagnosis, to offer OTC appropriately. However, disease relapse necessitating more intensive treatments remains a challenge. This study additionally highlights the importance of routine assessment and documentation of reproductive status in haematology/oncology follow-up. STUDY FUNDING/COMPETING INTEREST(S): K.D. is supported by a CRUK grant (C157/A25193). This work was undertaken in part in the MRC Centre for Reproductive Health, (supported by MRC grant MR/N022556/1). R.A.A. has received consulting fees from Ferring and Roche Diagnostics; payment from Merck and IBSA for educational events; and laboratory materials from Roche Diagnostics. The other authors have no competing interests to declare. TRIAL REGISTRATION NUMBER: N/A.

A 20-year overview of fertility preservation in boys: new insights gained through a comprehensive international survey.

STUDY QUESTION: Twenty years after the inception of the first fertility preservation programme for pre-pubertal boys, what are the current international practices with regard to cryopreservation of immature testicular tissue? SUMMARY ANSWER: Worldwide, testicular tissue has been cryopreserved from over 3000 boys under the age of 18 years for a variety of malignant and non-malignant indications; there is variability in practices related to eligibility, clinical assessment, storage, and funding. WHAT IS KNOWN ALREADY: For male patients receiving gonadotoxic treatment prior to puberty, testicular tissue cryopreservation may provide a method of fertility preservation. While this technique remains experimental, an increasing number of centres worldwide are cryopreserving immature testicular tissue and are approaching clinical application of methods to use this stored tissue to restore fertility. As such, standards for quality assurance and clinical care in preserving immature testicular tissue should be established. STUDY DESIGN SIZE DURATION: A detailed survey was sent to 17 centres within the recently established ORCHID-NET consortium, which offer testicular tissue cryopreservation to patients under the age of 18 years. The study encompassed 60 questions and remained open from 1 July to 1 November 2022. PARTICIPANTS/MATERIALS SETTING METHODS: Of the 17 invited centres, 16 completed the survey, with representation from Europe, Australia, and the USA. Collectively, these centres have cryopreserved testicular tissue from patients under the age of 18 years. Data are presented using descriptive analysis. MAIN RESULTS AND THE ROLE OF CHANCE: Since the establishment of the first formal fertility preservation programme for pre-pubertal males in 2002, these 16 centres have cryopreserved tissue from 3118 patients under the age of 18 years, with both malignant (60.4%) and non-malignant (39.6%) diagnoses. All centres perform unilateral biopsies, while 6/16 sometimes perform bilateral biopsies. When cryopreserving tissue, 9/16 centres preserve fragments sized ≤5 mm3 with the remainder preserving fragments sized 6-20 mm3. Dimethylsulphoxide is commonly used as a cryoprotectant, with medium supplements varying across centres. There are variations in funding source, storage duration, and follow-up practice. Research, with consent, is conducted on stored tissue in 13/16 centres. LIMITATIONS REASONS FOR CAUTION: While this is a multi-national study, it will not encompass every centre worldwide that is cryopreserving testicular tissue from males under 18 years of age. As such, it is likely that the actual number of patients is even higher than we report. Whilst the study is likely to reflect global practice overall, it will not provide a complete picture of practices in every centre. WIDER IMPLICATIONS OF THE FINDINGS: Given the research advances, it is reasonable to suggest that cryopreserved immature testicular tissue will in the future be used clinically to restore fertility. The growing number of patients undergoing this procedure necessitates collaboration between centres to better harmonize clinical and research protocols evaluating tissue function and clinical outcomes in these patients. STUDY FUNDING/COMPETING INTERESTS: K.D. is supported by a CRUK grant (C157/A25193). R.T.M. is supported by an UK Research and Innovation (UKRI) Future Leaders Fellowship (MR/S017151/1). The MRC Centre for Reproductive Health at the University of Edinburgh is supported by MRC (MR/N022556/1). C.L.M. is funded by Kika86 and ZonMW TAS 116003002. A.M.M.v.P. is supported by ZonMW TAS 116003002. E.G. was supported by the Research Program of the Research Foundation-Flanders (G.0109.18N), Kom op tegen Kanker, the Strategic Research Program (VUB_SRP89), and the Scientific Fund Willy Gepts. J.-B.S. is supported by the Swedish Childhood Cancer Foundation (TJ2020-0026). The work of NORDFERTIL is supported by the Swedish Childhood Cancer Foundation (PR2019-0123; PR2022-0115), the Swedish Research Council (2018-03094; 2021-02107), and the Birgitta and Carl-Axel Rydbeck's Research Grant for Paediatric Research (2020-00348; 2021-00073; 2022-00317; 2023-00353). C.E is supported by the Health Department of the Basque Government (Grants 2019111068 and 2022111067) and Inocente Inocente Foundation (FII22/001). M.P.R. is funded by a Medical Research Council Centre for Reproductive Health Grant No: MR/N022556/1. A.F. and N.R. received support from a French national research grant PHRC No. 2008/071/HP obtained by the French Institute of Cancer and the French Healthcare Organization. K.E.O. is funded by the University of Pittsburgh Medical Center and the US National Institutes of Health HD100197. V.B-L is supported by the French National Institute of Cancer (Grant Seq21-026). Y.J. is supported by the Royal Children's Hospital Foundation and a Medical Research Future Fund MRFAR000308. E.G., N.N., S.S., C.L.M., A.M.M.v.P., C.E., R.T.M., K.D., M.P.R. are members of COST Action CA20119 (ANDRONET) supported by COST (European Cooperation in Science and Technology). The Danish Child Cancer Foundation is also thanked for financial support (C.Y.A.). The authors declare no competing interests. TRIAL REGISTRATION NUMBER: N/A.

Impact of taxane-based chemotherapeutics on male reproductive function.

Lay summary: Men and boys with cancer treated with chemotherapy are known to have reduced fertility following their treatment. This is because some chemotherapy drugs can damage the cells in the testicles that make sperm. This study found there is limited information available on the effect of one group of chemotherapy drugs, called taxanes, on testicular function and fertility. More studies are needed to aid clinicians in advising patients on how this taxane-based chemotherapy may affect their future fertility.