Preservation of fertility in females with haematological malignancy: Review

The impact of culture conditions on early follicle recruitment and growth from human ovarian cortex biopsies in vitro

OBJECTIVE

To investigate the effects of a dynamic fluidic culture system on early in vitro folliculogenesis in standardized ovarian cortex biopsies.

DESIGN

Cortical small strips were cultured for 6 days in a conventional static or in a dynamic fluidic culture system.

SETTING

University-affiliated laboratory with an associated cryobank facility.

PATIENT(S)

Ovarian cortex from postpuberal female cancer patients (26.1 ± 1.3 y) who opted for cryopreservation of their tissue for fertility protection before gonadotoxic cancer therapy. With informed consent of the Institutional Ethics Committee, part of the tissue was available for patient-related research studies.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The viability and proliferative capacity of the cortex biopsies were evaluated by chemiluminescent microparticle immunoassay for detection of in vitro produced E2 and P in the supernate, by viable follicle counting via calcein staining, by histologic analyses, and by total RNA preparation and reverse transcription for real-time polymerase chain reaction of selected early folliculogenesis genes.

RESULT(S)

The data support the notion that early follicle development can be better achieved in vitro in a dynamic fluidic culture system. The findings are based on the presence of more viable follicles, higher expression levels of early folliculogenesis genes KIT-L, INHB, and GDF9, and the absence of premature luteinization of follicles.

CONCLUSION(S)

This study provides evidence that dynamic fluidic culture is a promising approach for investigating early follicular recruitment and growth in cortical biopsies. It may serve as a first step in a multistep culture system to design a complex in vitro system for complete folliculogenesis.

Risk of transferring malignant cells with transplanted frozen-thawed ovarian tissue

Ovarian tissue cryopreservation and transplantation is a real option to preserve and restore fertility in young cancer patients. However, there is a concern regarding the possible presence of malignant cells in the ovarian tissue, which could lead to recurrence of the primary disease after reimplantation. A review of the existing literature was done to evaluate the risk of transplanting malignant cells in case of the main malignant indications for ovarian tissue cryopreservation. For ovarian tissue from patients with hematologic malignancies, it is of paramount importance to identify minimal residual disease before ovarian tissue transplantation. Indeed, these pathologies, reviewed here in detail, are considered to be most at risk of ovarian metastasis.

Future Directions in Oncofertility and Fertility Preservation: A Report from the 2011 Oncofertility Consortium Conference

Fertility impairment and loss due to cancer or its treatment is a significant survivorship consideration for many pediatric, adolescent, and young adult cancer survivors. Chemotherapeutics, radiation, and surgery can impact the future fertility of men, women, and children with cancer. The field of oncofertility, founded to ensure the reproductive future of cancer survivors, gained momentum with 5 years of funding through a 2007 National Institutes of Health Roadmap Grant for Biomedical Research. This report from working group meetings at the fifth annual Oncofertility Consortium Conference speaks to the present state of oncofertility research and clinical care, existing gaps, and future directions for the field. This summary from conference participants and leaders in the field addresses the science, clinical specialties, and academic scholarship that can guide the field as the Roadmap Grant funding comes to a close.

Safety assessment of ovarian cryopreservation and transplantation in nude mice bearing human epithelial ovarian cancer

OBJECTIVE

Nude mice with orthotopic transplantation of human ovarian epithelial cancer were used to investigate screening criteria for paraneoplastic normal ovarian tissue and the security of the freezing and thawing for ovarian tissue transplantation.

METHODS

Expression of CK-7, CA125, P53, survivin, MMP-2/TIMP- 2 in paraneoplastic normal ovarian tissues were detected by RT-PCR as well as immunohistochemistry. The tissues of the groups with all negative indicators of RT-PCR, all negative indicators of immunohistochemistry, negative expression of CK-7, CA125 and survivin, positive expression of CK-7, CA125 and survivin, cancer tissues and normal ovarian tissues of nude mice were used for freezing and thawing transplantation, to analyze overt and occult carcinogenesis rates after transplantation.

RESULTS

When all indicators or the main indicators, CK-7, CA125 and survivin, were negative, tumorigenesis did not occur after transplantation. In addition the occult carcinogenesis rate was lower than in the group with positive expression of CK-7, CA125 and survivin (P<0.01). After subcutaneous and orthotopic transplantation of ovarian tissues, rates did not change (P>0.05). There was no statistical significance among rates after transplantation of ovarian tissues which were obtained under different severity conditions (P>0.05).

CONCLUSION

Negative expression of CK-7, CA125 and survivin can be treated as screening criteria for security of ovarian tissues for transplantation. Immunohistochemical methods can be used as the primary detection approach. Both subcutaneous and orthotopic transplantation are safe. The initial severity does not affect the carcinogenesis rate after tissue transplantation. Freezing and thawing ovarian tissue transplantation in nude mice with human epithelial ovarian carcinoma is feasible and safe.

Factors related to unstained areas in whole ewe ovaries perfused with a metabolic marker

STUDY QUESTION

What factors are associated with the presence of areas unexposed to the perfusate after whole ovary perfusion?

SUMMARY ANSWER

Over half the ovaries perfused with the metabolic marker methylthiazolyl blue tetrazolium (MTT) were incompletely stained. Incomplete staining was statistically significantly associated with a small ovarian slice surface area, inexperience of the experimenter, and the presence of a corpus luteum.

WHAT IS KNOWN ALREADY

Whole ovary cryopreservation followed by vascular auto-transplantation has provided poor outcomes as an alternative way to safeguard fertility. Perfusion, commonly used to expose the ovaries to cryoprotectants, may miss areas excluded from the vascular network, explaining subsequent poor ovarian functionality.

STUDY DESIGN, SIZE, DURATION

An observational study of 360 ewe ovaries stained by in vitro perfusion with MTT as a qualitative marker of tissue blood supply was performed. A logistic regression model was built to identify factors associated with incomplete ovary staining.

MATERIALS, SETTING, METHODS

Whole ewe ovaries with their vascular pedicles were perfused at 0.35 ml/min with 1 g/l MTT for 2 h at 39°C under 19 experimental conditions. The pedicles were removed and the ovaries cut in half sagittally and photographed. The unstained area of the slice surface was measured. Times from ovary collection to ovary rinsing and to MTT perfusion initiation, ovary weight and slice surface area, presence of a corpus luteum and operator experience (number of ovaries previously perfused) were recorded. Pedicle MTT staining was quantified at 564 nm after solubilization in alcohol.

MAIN RESULTS AND THE ROLE OF CHANCE

Unstained areas were observed in 64.4% of the ovaries. Multivariate analysis found that incomplete ovary staining was independently associated with lower experimenter experience (P < 0.02), smaller ovary slice surface area (P < 0.0001) and presence of a corpus luteum (P < 0.01). The presence of unstained areas was independent from experimental conditions. The rate of incomplete ovary staining decreased from 83 to 60% beyond the 80th perfused ovary (P < 0.0001).

LIMITATIONS, REASONS FOR CAUTION

Descriptive study.

WIDER IMPLICATIONS OF THE FINDINGS

Blood-supply impairments that result in incomplete perfusion might adversely affect outcomes after whole ovary cryopreservation. Improved perfusion techniques should enhance success.

Optimizing cryoprotectant perfusion conditions for intact ovary: a bovine model

PURPOSE

The aim of this study was to detect the effects of different perfusion pressure and different length of perfusion period on whole ovarian cryopreservation

METHODS

Bovine whole ovaries were vitrified-warmed. The ovaries were divided into the experimental groups according to different perfusion pressure and different length of perfusion period. Follicular viability was assessed using the trypan blue test; the percentage of morphologically normal primordial follicles and the 17-β estradiol level in the culture supernatants were measured.

RESULTS

When perfusion pressure was 100 mmHg, and the length of perfusion period was 40 min, the viability of ovarian tissues in bovine whole ovarian cryopreservation were higher than other protocols.

CONCLUSION

Protocol IIb (the perfusion pressure was 100 mmHg, and the length of perfusion period was 40 min) was appropriate for bovine whole ovarian cryopreservation.

Fertility Preservation Methods in Breast Cancer

Thanks to the recent advances in reproductive medicine, more and more young women with breast cancer may be offered the possibility of preserving their fertility. Fertility can be endangered by chemotherapy, by treatment duration and by patient's age at diagnosis. The currently available means to preserve a young woman's fertility are pharmacological protection with gonadotrophin-releasing hormone analogues during chemotherapy, and ovarian tissue or oocyte/embryo freezing before treatment. New future venues, including in vitro maturation, will improve the feasibility and efficacy of the fertility preservation methods in breast cancer patients.

How do chemotherapeutic agents damage the ovary?

BACKGROUND

Chemotherapy treatment in premenopausal women is associated with an increased risk of premature ovarian failure (POF) but the exact mechanism through which this occurs is uncertain. In this review we examine the current evidence for the direct action of chemotherapeutic agents on the ovary and discuss possible molecular pathways through which follicle loss may occur.

METHODS

A systemic search of the databases, PubMed and Google Scholar, was made for all English language articles through to 2011 in each subject area discussed.

RESULTS

POF results from the loss of primordial follicles but this is not necessarily a direct effect of the chemotherapeutic agents. Instead, the disappearance of primordial follicles could be due to an increased rate of growth initiation to replace damaged developing follicles. Likewise, the loss of oocytes need not necessarily be a direct result of damage: evidence suggests that chemotherapy drugs can also induce oocyte death indirectly via damage to somatic cells. Specific molecular mechanisms and likely ovarian targets are discussed for some of the anti-cancer drugs most commonly used to treat premenopausal women. Finally, we consider current and prospective methods of preserving fertility.

CONCLUSIONS

It is likely that different chemotherapeutic drugs act through a range of mechanisms and on different target cells. More research into the cellular mechanisms underpinning chemotherapy-induced follicle loss could lead to the generation of treatments specifically designed to prevent POF.

[Cancer, fertility preservation and gonadotropins]

The recent emergence of oncofertility raises the question of ovarian stimulation and its risks when performed for oocyte or/and embryo cryopreservation in a fertility preservation program. The relation between ovarian stimulation and cancer has been marked by the possible direct or indirect tumorigenic role for pituitary gonadotrophins in the tumorogenesis. Although the growth of many gonadal and extragonadal tumors is stimulated by gonadal sex hormones, whose production is regulated by gonadotrophins, there is still a lack of data to consider FSH and LH as tumor promoters. The purpose of this brief review is to present on one hand, the questions raised by the administration of exogenous gonadotrophins in cancer patients and on the other, to evaluate both experimental and clinical data about the possible relation between gonadotrophins and tumorogenesis.

Validation of a new metabolic marker to assess the vascular viability of vitrified whole sheep ovaries

BACKGROUND

Whole ovary cryopreservation has been suggested as a means to preserve fertility. In animal models, autologous cryopreserved ovary transplants frequently undergo thrombosis and a method to assess the vascular viability of cryopreserved ovaries would be valuable. We developed a staining method using methylthiazolyl blue tetrazolium (MTT, a metabolic marker) to assess the pedicle metabolism of whole ovaries vitrified using cryoprotectant called 'VS4'.

METHODS

Whole sheep ovaries were perfused with MTT (1 g/l). In one group, ovarian tissue lesions were induced by immersing the ovarian pedicle in medium at 53°C or 65°C or in liquid nitrogen prior to MTT perfusion. In the second group, several metabolic substrates (d-glucose, l-glucose and pyruvic acid) and inhibitors [2-deoxy-d-glucose for d-glucose metabolism, azide for mitochondrial respiration and diphenyleneiodonium (DPI) for NADPH oxidase (an effector of the pentose phosphate pathway)] were added to the MTT stain. The third group was subjected to VS4 ± vitrification/warming prior to MTT perfusion. Pedicle MTT staining was assessed qualitatively by histological examination of frozen sections or quantified at 564 nm after solubilization in alcohol.

RESULTS

MTT strongly and reproducibly stained the vascular smooth muscle. Heating at 53°C or 65°C or cooling in liquid nitrogen significantly diminished MTT staining by 48% (P = 0.001, n = 10), 94% (P = 0.0002, n = 10) and 94% (P = 0.0002, n = 10), respectively. MTT staining was affected by d-glucose metabolism: absence of d-glucose, substitution of unmetabolized l-glucose for d-glucose or addition of 2-deoxy-d-glucose significantly decreased MTT staining by 44% (P < 0.01, n = 10), 45% (P < 0.01, n = 10) and 29% (P < 0.01, n = 10), respectively. Pyruvic acid failed to correct the MTT staining decrease induced by d-glucose deprivation and azide did not decrease MTT staining, suggesting that MTT staining could be independent of mitochondrial metabolism. Adding DPI significantly inhibited MTT staining by 25% (P < 0.001, n = 10), suggesting involvement of the pentose phosphate pathway's effectors. Compared with controls, VS4-vitrified/warmed pedicles showed significantly less MTT staining (-30%, P < 0.005, n = 10), with unstained foci, whereas unvitrified VS4-exposed pedicles showed no difference.

CONCLUSIONS

MTT can serve as a qualitative and quantitative vascular viability marker.VS4 vitrification caused alterations in ovarian vascular metabolism. MTT staining should allow accurate comparisons of whole-organ cryoprotection protocols.

Fertility preservation in girls

Children that undergo treatment for cancer are at risk of suffering from subfertility or hormonal dysfunction due to the detrimental effects of radiotherapy and chemotherapeutic agents on the gonads. Cryopreservation of ovarian tissue prior to treatment offers the possibility of restoring gonadal function after resumption of therapy. Effective counseling and management of pediatric patients is crucial for preserving their future reproductive potential. The purpose of this article is to review recent literature and to revise recommendations we made in a 2007 article. Pediatric hemato-oncology, reproductive endocrinology, surgery, anesthesia and bioethics perspectives are discussed and integrated to propose guidelines for offering ovarian cryopreservation to premenarcheal girls with cancer.

[Cryopreserved ovaries: models of experimental grafting]

Childhood cancers account for 1% of malignant tumors. As a result of advances in treatment, almost 80% of children and adolescents who currently receive a diagnosis of cancer become long-term survivors. Assessment of potential for fertility preservation should thus be a systematic element of care for children treated for a malignant tumor (high-dose chemotherapy with alkylizing agents, radiation therapy including the gonads) or those receiving hematopoietic stem cell grafts for malignant or benign disease (sickle-cell anemia, immune deficit). Potential adverse consequences of treatment include impaired puberty and fertility due to gonadal removal, genital tract injury or damage to germ cells from adjuvant therapy. Advances in assisted reproductive technologies have led to new possibilities for the prevention and treatment of infertility. Among them, cryopreservation of ovarian tissue appears to be the most promising, or perhaps the only one available before puberty with encouraging results. Nevertheless the uncertainties, or even risks, related to these treatments, should not be neglected. We review experimental data in mouse and sheep animal models. The results demonstrate that immature ovarian grafting can restore spontaneous puberty and fertility in both models. This study addresses the very important issue of epigenetics, and provides valuable information for the study of ovarian transplantation, suggesting that these procedures do not perturb normal epigenetic marks. These results are highly relevant to the question of immature cortex reimplantation.

Retransplantation of cryopreserved ovarian tissue: the first live birth in Germany

BACKGROUND

Cryopreserved ovarian tissue can be retransplanted to restore fertility after radiation or chemotherapy. To date, 15 live births after retransplantation have been reported worldwide. We report the first pregnancy and the first live birth after retransplantation in Germany.

CASE REPORT

A 25-year-old female patient received initial chemotherapy and radiation of the mediastinum for Hodgkin's lymphoma in 2003 and suffered a relapse two years later. Ovarian tissue was laparoscopically removed and cryopreserved, and she was then treated with high-dose chemotherapy and stem cell transplantation. She remained in remission for 5 years and she could not conceive during this time. The cryopreserved ovarian tissue was thawed and laparoscopically retransplanted into a peritoneal pouch in the ovarian fossa of the right pelvic wall. Three months later, her menopausal symptoms resolved, and she had her first spontaneous menstruation. Six months after retransplantation, after two normal menstrual cycles, low-dose follicle stimulating hormone (FSH) treatment induced the appearance of a dominant follicle in the tissue graft. Ovulation was then induced with human chorionic gonadotropin (HCG), whereupon the patient conceived naturally. After an uncomplicated pregnancy, she bore a healthy child by Caesarean section on 10 October 2011. Histological examination of biopsy specimens revealed that the ovarian tissue of the graft contained follicles in various stages of development, while the original ovaries contained only structures without any reproductive potential.

CONCLUSION

This was the first live birth after retransplantation of cryopreserved ovarian tissue in Germany and also the first case with histological confirmation that the oocyte from which the patient conceived could only have come from the retransplanted tissue. In general, young women who will be undergoing chemotherapy and/or radiotherapy for cancer must be informed and counseled about the available options for fertility preservation.

Live birth after ovarian tissue autotransplantation following overnight transportation before cryopreservation

OBJECTIVE

To describe the first live birth after transplantation of ovarian tissue following overnight transportation of the tissue before freezing.

DESIGN

Technical note.

SETTING

University department of obstetrics and gynecology.

PATIENT(S)

A 25-year-old cancer survivor with previous Hodgkin disease and relapse.

INTERVENTION(S)

The ovarian tissue was kept cool for >20 hours in a special transport medium and a special cooling device before it was cryopreserved. After premature ovarian failure due to preconditioning chemotherapy for bone marrow transplantation, the cryopreserved ovarian tissue was transplanted orthotopically.

MAIN OUTCOME MEASURE(S)

Resumption of ovarian function after transplantation, recovery of fertility, and pregnancy.

RESULT(S)

Ovarian function returned in the patient 3 months after transplantation, as shown by follicle development and estrogen production. During the fifth menstrual cycle, mild stimulation with FSH was initiated in accordance with a low-dose protocol. When ultrasonography revealed a follicle 18-20 mm in size in the ovarian graft, hCG was added and the patient had sexual intercourse at the optimal time point. On day 14 of the luteal phase, hCG concentration and vaginal echography confirmed a viable intrauterine pregnancy, which resulted in a healthy live birth.

CONCLUSION(S)

Overnight transportation of ovarian tissue appears to be possible in combination with appropriate transportation logistics. However, further investigations are needed before this procedure can be offered as a chance for women to preserve fertility independently of direct access to a tissue-processing bank.

Cryopreservation and fertility: current and prospective possibilities for female cancer patients

With the evolution of the treatment of malignant neoplasms, the survival rates of patients undergoing chemo- or radiotherapy are increasing. The continuous development of techniques of assisted human reproduction has led to important strategies in an attempt to maintain reproductive function in patients subjected to treatment of neoplastic diseases, among them cryopreservation of embryos, gametes, and ovarian cortical tissue. The freezing of ovarian tissue is currently being proposed with the primary purpose of preserving ovarian function in these patients. Currently, the major challenge of groups working with preservation of fertility is the use of cryopreserved ovarian tissue after disease remission. The main alternatives presented today are the implantation of hetero- or orthotopic tissue and isolation of immature follicles from ovarian tissue followed by in vitro maturation and assisted reproduction procedures.

Viability assessment of fresh and frozen/thawed isolated human follicles: reliability of two methods (Trypan blue and Calcein AM/ethidium homodimer-1)

PURPOSE

To assess the reliability of trypan blue (TB) and calcein AM/ethidium homodimer-1 (CaAM/EthD-1) staining to evaluate the viability of fresh and thawed human ovarian follicles.

METHODS

Isolated follicles from fresh and thawed cortex were stained using TB versus CaAM/EthD-1 methods (n = 10 patients). Measurements were performed by two independent observers. The reliability was evaluated by intraclass correlation coefficient (ICC) and the differences between paired measurements were tested by the Wilcoxon test.

RESULTS

Inter-observer reliability was excellent for each method. Nevertheless, it was even better with the TB method (ICC = 0.83) compared with CaAM/EthD-1 (ICC = 0.75). Moreover, the ICCs for viability measurements using the two methods were good for each observer (observer 1: ICC = 0.49; observer 2: ICC = 0.40).

CONCLUSION

Compared with CaAM/EthD-1, TB appears to be more reliable as a staining method for follicle viability evaluation. TB staining is a quick and useful method, complementary to histological analysis for quality control in ovarian tissue cryopreservation.

Cryopreservation time does not decrease follicular viability in ovarian tissue frozen for fertility preservation

OBJECTIVE

To determine the effect of storage duration on cryopreserved ovarian tissue using fresh and frozen-thawed samples.

METHODS

Seventeen fertile patients underwent an ovarian biopsy during elective laparoscopic tubal ligation. The tissue sample was divided into three parts: one part was processed fresh (FG), and two were slowly frozen, cryopreserved for 30 (G30) or 180 days (G180), thawed and analyzed. Follicular density, follicular viability, and steroidogenic capacity were assessed.

RESULTS

We observed no differences between the groups in follicular density, which was assessed in hematoxylin and eosin-stained tissue sections. A heterogeneous follicular distribution was observed in the parenchyma, with a mean density of 361.3±255.4, 454.9±676.3, and 296.8±269.0 follicles/mm(3) for FG, G30 and G180, respectively (p = 0.46). Follicular viability was greater in FG (93.4%) when compared with the cryopreserved tissues (70.8% for G30 (p<0.001) and 78.4% for G180 (p<0.001)), with no difference in viability between the frozen samples (p>0.05). The steroidogenic capacity of the tissue was not significantly reduced following cryopreservation.

CONCLUSION

The slow freezing procedures used for ovarian cryopreservation are capable of preserving follicular viability and maintaining the steroidogenic capacity of the tissue despite a roughly 30% decrease in follicular viability. Furthermore, short-term storage of ovarian tissue does not appear to compromise follicle integrity.