The past, present and future of fertility preservation in cancer patients

Robotic-assisted fertility sparing surgery in gynecological oncology

While gynecological malignancies are more commonly diagnosed in elderly women, a substantial proportion of women will still be diagnosed with some type of gynecologic cancer during their reproductive age. Over 10% of newly diagnosed ovarian cancers and over one third of newly diagnosed cervical cancers involve women who are under the age of 45. This, coupled with the rising trend of women having their first child after the age of 35, has led to a concerning prevalence of complex fertility issues among women who have been diagnosed with cancer. Since the advent of robotic-assisted surgeries in gynecology, there has been a rise in the occurrence of these procedures. Fertility preserving gynecological surgeries require precise management in order to avoid fertility disorders. Therefore, we conducted a narrative review of robotic assisted fertility sparing surgery in gynecologic malignancies in order to highlight the role of this approach in preserving fertility.

[Desire for pregnancy and breast cancer]

Breast cancer affects about 3,000 new women of childbearing age each year. The desire for pregnancy is therefore a frequent issue in the management of breast cancer. We reviewed the current state of knowledge and recommendations in high-risk women, on the consideration of this desire for pregnancy in therapeutic management, the way to approach it, the preservation of fertility in the care process and finally on the outcomes of pregnancy after breast cancer. We evaluated the desire for pregnancy, qualitatively and quantitatively, after breast cancer through a literature review.

The challenges of fertility preservation in cancer patients: an interview with Michael Grynberg

Michaël Grynberg is an Obstetrician Gynecologist specialized in reproductive medicine. After 1 year as a visiting fellow in the Department of Reproductive Medicine at Cornell University, he returned to work in France as an Attending Physician in the Division of Reproductive Medicine at the University Hospital Antoine Béclère, Clamart, France. In 2011, he completed his PhD on the topic of the regulation of follicular growth and anti-Müllerian hormone production. Since 2014, he has been Professor of Reproductive Medicine and the Head of the Department of Reproductive Medicine and Fertility Preservation at the University Hospital Jean Verdier, Bondy, France. Since 2017, he has become the Head of the Department of Reproductive Medicine and Fertility Preservation at the University Hospital Antoine Béclère, Clamart, France. In addition, he is an active member of the basic research unit INSERM U 1133, University Paris Diderot-CNRS UMR 8251. His research interests initially include the assessment of ovarian follicular status and the regulation of anti-Müllerian hormone, a key peptide in the ovarian function. Over the past 5 years, he has expanded his field of research with oncofertility. Indeed, female fertility preservation has recently emerged in the field of reproductive medicine. He is a pioneer on this topic in France and has recently become the President of the French Society of Oncofertility. He, along with his colleagues, has published over 100 peer-reviewed articles in international journals and books.

Early menopause: A hazard to a woman's health

Early menopause or premature ovarian insufficiency (POI) is a common cause of infertility in women and affects about one per cent of young women. This disorder has significant psychological sequelae and major health implications. Its relevance has increased in recent years due to the fact that age of motherhood is being delayed in developed countries, with the risk of having either primary ovarian insufficiency or less possibilities of pregnancy. The main characteristics are absence of ovulation, amenorrhoea and high levels of serum gonadothropins (hypergonadotropic hypogonadism). Although the aetiology remains uncertain in most cases, several rare specific causes have been elucidated. Potential causes for POI are iatrogenic (ovarian surgery, radiotherapy or chemotherapy), environmental factors, viral infections, metabolic and autoinmune diseases, and genetic alterations. Because of the association with other autoimmune diseases, close follow up is recommended in patients with POI. The traditional indicators to evaluate ovarian ageing are age, serum hormonal levels, anti-Mullerian hormone, antral follicle count, and ultrasonography of ovaries. Hormone replacement therapy remains the mainstay of treatment, and the best chance of achieving a pregnancy is through oocyte donation. This article aims to present an overview of potential causes, clinical manifestations, and treatment options of POI.

Vitamin A prevents round spermatid nuclear damage and promotes the production of motile sperm during in vitro maturation of vitrified pre-pubertal mouse testicular tissue

STUDY QUESTION

Does vitamin A (retinol, Rol) prevent round spermatid nuclear damage and increase the production of motile sperm during in vitro maturation of vitrified pre-pubertal mouse testicular tissue?

SUMMARY ANSWER

The supplementation of an in vitro culture of ~0.75 mm³ testicular explants from pre-pubertal mice with Rol enhances spermatogenesis progression during the first spermatogenic wave.

WHAT IS KNOWN ALREADY

The production of functional spermatozoa in vitro has only been achieved in the mouse model and remains a rare event. Establishing an efficient culture medium for vitrified pre-pubertal testicular tissue is now a crucial step to improve the spermatic yield obtained in vitro. The role of Rol in promoting the differentiation of spermatogonia and their entry into meiosis is well established; however, it has been postulated that Rol is also required to support their full development into elongated spermatids.

STUDY DESIGN, SIZE, DURATION

A total of 60 testes from 6.5 days post-partum (dpp) mice were vitrified/warmed, cut into fragments and cultured for 30 days: 20 testes were used for light microscopy and histological analyses, 20 testes for DNA fragmentation assessment in round spermatids and 20 testes for induced sperm motility assessment. Overall, 16 testes of 6.5 dpp were used as in vitro fresh tissue controls and 12 testes of 36.5 dpp mice as in vivo controls. Testes were vitrified with the optimal solid surface vitrification procedure and cultured with an in vitro organ culture system until Day 30 (D30). Histological analysis, cell death, degenerating round spermatids, DNA fragmentation in round spermatids and induced sperm motility were assessed. Testosterone levels were measured in media throughout the culture by radioimmunoassay.

MAIN RESULTS AND THE ROLE OF CHANCE

At D30, better tissue development together with higher differentiation of spermatogonial stem cells, and higher global cell division ability were observed for vitrified/warmed testicular fragments of ~0.75 mm³ with a culture medium supplemented with Rol compared to controls. During in vitro culture of vitrified pre-pubertal testicular tissue, Rol enhanced and maintained the entry of spermatogonia into meiosis and promoted a higher spermatic yield. Furthermore, decreased round spermatid nuclear alterations and DNA damage combined with induced sperm motility comparable to in vivo highlight the crucial role of Rol in the progression of spermatogenesis during the first wave.

LIMITATIONS, REASONS FOR CAUTION

Despite our promising results, the culture media will have to be further improved and adapted within the context of a human application.

WIDER IMPLICATIONS OF THE FINDINGS

The results have potential implications for the handling of human pre-pubertal testicular tissues cryopreserved for fertility preservation. However, because some alterations in round spermatids persist after in vitro culture with Rol, the procedure needs to be optimized before human application, bearing in mind that the murine and human spermatogenic processes differ in many respects.

LARGE SCALE DATA

None.

STUDY FUNDING AND COMPETING INTERESTS

This study was supported by a Ph.D. grant from the Normandy University and a financial support from 'la Ligue nationale contre le cancer' (both awarded to L.D.), funding from Rouen University Hospital, Institute for Research and Innovation in Biomedicine (IRIB) and Agence de la Biomédecine. The authors declare that there is no conflict of interest.

VSELs may obviate cryobanking of gonadal tissue in cancer patients for fertility preservation

Background

Infertility is an undesirable side effect and gonadal tissue banking is advocated in young cancer patients who are unable to preserve embryos or gametes prior to oncotherapy to achieve biological parenthood later on. Banking gonadal tissue is challenging and protocols to mature gametes in vitro are not yet clinically established. Transplanting ovarian cortical tissue at hetero-or orthotopic sites in women and bone marrow transplantation (BMT) in both men and women has resulted in spontaneous recovery of fertility, pregnancy and live births. Various studies in humans and mice suggest that genetic origin of offspring after BMT is similar to transplanted patient and not the donor. Thus the source of oocytes/sperm which result in spontaneous pregnancies still remains contentious.

Findings

Very small embryonic-like stem cells (VSELs) have been reported in adult human testis and ovary, in azoospermic testicular biopsies from survivors of childhood cancer and also in women with premature ovarian failure and menopause. VSELs survive chemotherapy because of their quiescent nature and can be detected in chemoablated mice gonads at protein and mRNA level and also by flow cytometry. Surviving VSELs spontaneously differentiate into oocyte-like structures and sperm when inhibitory factors are overcome in vitro. Transplantation of mesenchymal cells (isolated from different sources) has led to regeneration of chemoablated mouse gonads and also live births. Spermatogenesis is also restored from endogenous stem cells on inter-tubular transplantation of Sertoli cells in chemoablated mouse testis.

Conclusions

Endogenous VSELs (which survive oncotherapy) can possibly regenerate non-functional gonads in cancer survivors when exposed to a healthy niche in vitro or in vivo (by way of transplanting mesenchymal cells which secrete trophic factors required for endogenous VSELs to differentiate into gametes). Presence of VSELs can also explain spontaneous pregnancies after BMT and cortical tissue transplantation (at heterotopic or orthotopic sites). This understanding once verified and accepted by the scientific community could obviate the need to remove whole ovary or testicular biopsy for cryopreservation prior to oncotherapy.