The first Australian experience of heterotopic grafting of cryopreserved ovarian tissue: evidence of establishment of normal ovarian function

A Systematic Review of Ovarian Tissue Transplantation Outcomes by Ovarian Tissue Processing Size for Cryopreservation

Ovarian tissue cryopreservation (OTC) is the only pre-treatment option currently available to preserve fertility for prepubescent girls and patients who cannot undergo ovarian stimulation. Currently, there is no standardized method of processing ovarian tissue for cryopreservation, despite evidence that fragmentation of ovaries may trigger primordial follicle activation. Because fragmentation may influence ovarian transplant function, the purpose of this systematic review was (1) to identify the processing sizes and dimensions of ovarian tissue within sites around the world, and (2) to examine the reported outcomes of ovarian tissue transplantation including, reported duration of hormone restoration, pregnancy, and live birth. A total of 2,252 abstracts were screened against the inclusion criteria. In this systematic review, 103 studies were included for analysis of tissue processing size and 21 studies were included for analysis of ovarian transplantation outcomes. Only studies where ovarian tissue was cryopreserved (via slow freezing or vitrification) and transplanted orthotopically were included in the review. The size of cryopreserved ovarian tissue was categorized based on dimensions into strips, squares, and fragments. Of the 103 studies, 58 fertility preservation sites were identified that processed ovarian tissue into strips (62%), squares (25.8%), or fragments (31%). Ovarian tissue transplantation was performed in 92 participants that had ovarian tissue cryopreserved into strips (n = 51), squares (n = 37), and fragments (n = 4). All participants had ovarian tissue cryopreserved by slow freezing. The pregnancy rate was 81.3%, 45.5%, 66.7% in the strips, squares, fragment groups, respectively. The live birth rate was 56.3%, 18.2%, 66.7% in the strips, squares, fragment groups, respectively. The mean time from ovarian tissue transplantation to ovarian hormone restoration was 3.88 months, 3.56 months, and 3 months in the strips, squares, and fragments groups, respectively. There was no significant difference between the time of ovarian function' restoration and the size of ovarian tissue. Transplantation of ovarian tissue, regardless of its processing dimensions, restores ovarian hormone activity in the participants that were reported in the literature. More detailed information about the tissue processing size and outcomes post-transplant are required to identify a preferred or more successful processing method.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk], identifier [CRD42020189120].

Ovarian tissue bank for fertility preservation and anti-menopause hormone replacement

Traditional fertility preservation methods such as embryo or oocyte cryopreservation cannot meet the needs of a cancer patient or for personal reasons. The cryopreservation of ovarian tissue can be an alternative and has become a hot spot to preserve fertility or hormone replacement. The freezing of ovarian tissue can be carried out at any time without ovarian hyperstimulation to retrieve follicles. It is an ideal strategy to preserve reproductive function in children, adolescent cancer patients, and patients who are in urgent need of cancer treatment. With the increasing demands of women with premature ovarian failure or in menopause, ovarian tissue transplantation is also an alternative for hormone replacement that can provide physiological doses of hormone levels, which can avoid a series of risks such as thrombosis, breast cancer, or other hormone-dependent tumors, caused by oral hormone replacement. Hence, ovarian tissue banking can be regarded as a mainstream strategy for fertility preservation and anti-menopause hormone replacement in further clinical investigation.

Fertility Preservation: How to Preserve Ovarian Function in Children, Adolescents and Adults

Chemotherapy, pelvic radiotherapy and ovarian surgery have known gonadotoxic effects that can lead to endocrine dysfunction, cessation of ovarian endocrine activity and early depletion of the ovarian reserve, causing a risk for future fertility problems, even in children. Important determinants of this risk are the patient’s age and ovarian reserve, type of treatment and dose. When the risk of premature ovarian insufficiency is high, fertility preservation strategies must be offered to the patient. Furthermore, fertility preservation may sometimes be needed in conditions other than cancer, such as in non-malignant diseases or in patients seeking fertility preservation for personal reasons. Oocyte and/or embryo vitrification and ovarian tissue cryopreservation are the two methods currently endorsed by the American Society for Reproductive Medicine, yielding encouraging results in terms of pregnancy and live birth rates. The choice of one technique above the other depends mostly on the age and pubertal status of the patient, and personal and medical circumstances. This review focuses on the available fertility preservation techniques, their appropriateness according to patient age and their efficacy in terms of pregnancy and live birth rates.

Ovarian tissue grafting: Lessons learnt from our experience with 55 grafts

Purpose

Uncertainties remain regarding the clinical efficacy of ovarian tissue cryopreservation and grafting. We report a retrospective analysis of reproductive outcomes and lessons learnt following 55 ovarian tissue transplant procedures at our center from 2006 to 2019.

Methods

We analyzed variables related to graft success such as tissue volume, follicular density, total follicular volume, and age on the duration of graft function.

Results

Follicular density and total follicular volume correlate positively with duration of graft function. All clinical pregnancies in our cohort occurred in women who were aged 35 or less at the time of ovarian tissue cryopreservation.

Conclusion

Graft success, as determined by eventual pregnancy and the longevity of graft function, may be impacted by factors including age at cryopreservation, follicular density, and total follicular volume.

Human Ovarian Cortex biobanking: A Fascinating Resource for Fertility Preservation in Cancer

Novel anti-cancer treatments have improved the survival rates of female young patients, reopening pregnancy issues for female cancer survivors affected by the tumor treatment-related infertility. This condition occurs in approximately one third of women of fertile age and is mainly dependent on gonadotoxic protocols, including radiation treatments. Besides routine procedures such as the hormonal induction of follicular growth and subsequent cryopreservation of oocytes or embryos, the ovarian protection by gonadotropin-releasing hormone (GnRH) agonists during chemotherapy as well as even gonadal shielding during radiotherapy, other innovative techniques are available today and need to be optimized to support their introduction into the clinical practice. These novel methods are hormone stimulation-free and include the ovarian cortex cryopreservation before anti-cancer treatments and its subsequent autologous reimplantation and a regenerative medicine approach using oocytes derived in vitro from ovarian stem cells (OSCs). For both procedures, the major benefit is related to the prompt recruitment and processing of the ovarian cortex fragments before gonadotoxic treatments. However, while the functional competence of oocytes within the cryopreserved cortex is not assessable, the in vitro maturation of OSCs to oocytes, allows to select the most competent eggs to be cryopreserved for fertility restoration.

Heterotopic transplantation of cryopreserved ovarian tissue in cancer patients: a case series

Transplantation of cryopreserved ovarian tissue offers patients a chance to preserve fertility during cancer treatment. In this study of ten young women with gynecological cancer, heterotopic sites were tested for serum hormones and follicle growth to estimate transplant longevity and prospects for assisted conception. Frozen-thawed grafts were implanted subcutaneously in the forearm (FA) (2 cases), the abdominal wall (AW) (11 cases), and the peritoneal lining (P) (3 cases) . In the follow-up of 36 months, a total of 80 ovarian cycles in different heterotopic sites were analyzed. FA and AW grafts had wildly fluctuating FSH, while estradiol (E2) reached preovulatory levels only in AW and P grafts. Follicular growth was active in P sites (1.2 ± 0.1 mm/d) and sluggish in FA and AW sites (0.4 ± 0.1 mm/d). A mature oocyte was only retrieved from the AW, while seven other aspirations were unsuccessful. Meanwhile, a patient delivered twice after treatment for Hodgkin's lymphoma when orthotopic transplantation was performed, first from an IVF cycle and subsequently from a natural cycle. In conclusion, these findings offer no strong encouragement for fertility preservation by transplanting cryopreserved ovarian tissue to subcutaneous sites, and although the peritoneal site gave better results, graft longevity averaged the same at around 3 years.

Cryopreservation of Human Ovarian Tissue: A Review

BACKGROUND

Cryopreservation of human ovarian tissue has been increasingly applied worldwide to safeguard fertility in cancer patients, notably in young girls and women who cannot delay the onset of their treatment. Moreover, it has been proposed to patients with benign pathologies with a risk of premature ovarian insufficiency. So far, more than 130 live births have been reported after transplantation of cryopreserved ovarian tissue, and almost all patients recovered their ovarian function after tissue reimplantation.

SUMMARY

This review aims to summarize the recent results described in the literature regarding human ovarian tissue cryopreservation in terms of methods and main results obtained so far. To cryopreserve human ovarian tissue, most studies describe a slow freezing/rapid thawing protocol, which is usually an adaptation of a protocol developed for sheep ovarian tissue. Since freezing has been shown to have a deleterious effect on ovarian stroma and granulosa cells, various research groups have been vitrifying ovarian tissue. Despite promising results, only 2 babies have been born after transplantation of vitrified/warmed ovarian tissue. Optimization of both cryopreservation strategies as well as thawing/warming protocols is therefore necessary to improve the survival of follicles in cryopreserved ovarian tissue.

KEY MESSAGES

Human ovarian tissue cryopreservation has been successfully applied worldwide to preserve fertility in patients with malignant or nonmalignant pathologies that have a detrimental effect on fertility. Human ovarian tissue cryopreservation could also be applied as an alternative to postpone pregnancy or menopause in healthy women. Slow freezing and vitrification procedures have been applied to cryopreserve human ovarian tissue, but both alternatives require optimization.

A case report and follow-up of the first live birth after heterotopic transplantation of cryopreserved ovarian tissue in Eastern Europe

Background

Ovarian insufficiency is a major concern for long-term cancer survivors. Although semen freezing is well established to preserve male fertility, the possibilities to secure post-cancer female fertility are mostly limited to oocyte or embryo freezing. These methods require time-consuming ovarian stimulation with or without in vitro fertilization (IVF) that evidently delays cancer therapy. Ovarian tissue cryopreservation and subsequent thawed tissue autotransplantation are considered the most promising alternative strategy for restoring the fertility of oncology patients, which has not yet received the full clinical acceptance. Therefore, all successful cases are needed to prove its reliability and safety.

Case presentation

Here we report a single case in Estonia, where a 28-year-old woman with malignant breast neoplasm had ovarian cortex cryopreserved before commencing gonadotoxic chemo- and radiotherapy. Two years after cancer therapy, the patient underwent heterotopic ovarian tissue transplantation into the lateral pelvic wall. The folliculogenesis was stimulated in the transplanted tissue by exogenous follicle-stimulating hormone and oocytes were collected under ultrasound guidance for IVF and embryo transfer. The healthy boy was born after full-term gestation in 2014, first in Eastern Europe.

Conclusion

Despite many countries have reported the first implementation of the ovarian tissue freezing and transplantation protocols, the data is still limited on the effectiveness of heterotopic ovarian transplant techniques. Thus, all case reports of heterotopic ovarian tissue transplantation and long-term follow-ups to describe the children’s health are valuable source of clinical experience.

Transplantation of frozen-thawed ovarian tissue: an update on worldwide activity published in peer-reviewed papers and on the Danish cohort

PURPOSE

The purpose of the study is to review all peer-reviewed published reports of women receiving ovarian tissue transplantation (OTT) with frozen/thawed tissue (OTC) with respect to age, diagnosis, transplantation site, fertility outcome, and potential side effects, including data from all women in the Danish program.

METHODS

A systematic review of the literature was performed in PubMed combined with results from all patients who had received OTT in Denmark up to December 2017.

RESULTS

OTT has been reported from 21 different countries comprising a total of 360 OTT procedures in 318 women. In nine women, malignancy was diagnosed after OTT; none were considered to be directly caused by the OTT. Despite a potential under reporting of cancer recurrence, there is currently no evidence to suggest that OTT causes reseeding of the original cancer. Renewed ovarian endocrine function was reported in 95% of the women. Half of all children born following OTT resulted from natural conception, and newborns were reported to be healthy except for one neonate with a chromosome anomaly with a family disposition. Women who conceived after OTT were significantly younger than those who failed.

CONCLUSION

This study found no indications of sufficient numbers of malignant cells present in the ovarian tissue to cause recurrence of cancer after OTT. Further, it is unlikely that OTC affects the well-being of children born. OTC is now an established method of fertility preservation in Denmark with public reimbursement. The current data encourage that women who require gonadotoxic treatment should be offered an individual evaluation considering fertility preservation.

Expectations and limitations of ovarian tissue transplantation

Constant progress in the diagnosis and treatment of cancer disease has increased the number and prognosis of cancer survivors. However, the toxic effects of chemotherapy and radiotherapy on ovarian function have resulted in premature ovarian failure. Patients are, therefore, still expecting methods to be developed to preserve their fertility successfully. Several potential options are available to preserve fertility in patients who face premature ovarian failure, including immature or mature oocyte and embryo cryopreservation. However, for children or prepubertal women needing immediate chemotherapy, cryopreservation of ovarian tissue is the only alternative. The ultimate aim of this strategy is to implant ovarian tissue into the pelvic cavity (orthotopic site) or in a heterotopic site once oncological treatment is completed and the patient is disease free. Transplantation of ovarian tissue with sufficiently large numbers of follicles could potentially restore endocrine function and allow multiple cycles for conception. However, the success of ovarian tissue transplantation still has multiple challenges, such as the low number of follicles in the graft that may affect their longevity as well as the survival of the tissue during ex vivo processing and subsequent transplantation. Therefore, this review aims to summarize the achievements of ovary grafting and the potential techniques that have been developed to improve ovarian graft survival.

Chapter 12 Human Ovarian Tissue Slow Freezing

Cryopreservation of human ovarian tissue is now being accepted as a mainstream ART laboratory procedure. The procedure described has been validated for use at the histological and functional level, and, recently, unequivocal evidence of preservation of primordial follicles has been demonstrated following twin births from cryopreserved ovarian tissue grafted at a heterotopic site.

Clinically applied procedures for human ovarian tissue cryopreservation result in different levels of efficacy and efficiency

PURPOSE

Different protocols are being used worldwide for the cryopreservation of human ovarian tissue for fertility preservation purposes. The efficiency and efficacy of the majority of these protocols has not been extensively evaluated, possibly resulting in sub-optimally cryopreserved ovarian tissue. To address the impact of this issue, we assessed the effects of two clinically successful human ovarian tissue slow-freezing cryopreservation procedures on the quality of the cryopreserved tissue.

METHODS

To differentiate between cryopreservation (_C) versus thawing (_T) related effects, four combinations of these two (A and B) very different cryopreservation/thawing protocols (A_CA_T, A_CB_T, B_CA_T, B_CB_T) were studied. Before and after cryopreservation and thawing, the percentage of living and morphologically normal follicles, as well as the overall tissue viability, was assessed.

RESULTS

Our experiments revealed that the choice of the cryopreservation protocol noticeably affected the overall tissue viability and percentage of living follicles, with a higher viability after protocol B_C when compared to A_C. No statistically significant differences in tissue viability were observed between the two thawing protocols, but thawing protocol B_T required considerably more human effort and materials than thawing protocol A_T. Tissue morphology was best retained using the B_CA_T combination.

CONCLUSION

Our results indicate that extensive and systematical evaluation of clinically used protocols is warranted.

Fertility Preservation in Children and Adolescents

Fertility preservation is the process by which either oocytes (eggs) or sperm undergo an intervention to preserve their use for future attempts at conception. Consideration of fertility preservation in the pediatric and adolescent population is important, as future childbearing is usually a central life goal. For postpubertal girls, both oocyte and embryo cryopreservation are standard of care and for postpubertal boys, sperm cryopreservation continues to be recommended. Although all the risks are unknown, it appears that fertility preservation in most cases does not worsen prognosis, allows for the birth of healthy children, and does not increase the chance of recurrence.

Ovarian tissue cryopreservation in girls undergoing haematopoietic stem cell transplant: experience of a single centre

Fertility after childhood haemopoietic stem cell transplant (HSCT) is a major concern. Conditioning regimens before HSCT present a high risk (>80%) of ovarian failure. Since 2000, we have proposed cryopreservation of ovarian tissue to female patients undergoing HSCT at our centre, to preserve future fertility. After clinical and haematological evaluation, the patients underwent ovarian tissue collection by laparoscopy. The tissue was analysed by histologic examination to detect any tumour contamination and then frozen following the slow freezing procedure and cryopreserved in liquid nitrogen. From August 2000 to September 2013, 47 patients planned to receive HSCT, underwent ovarian tissue cryopreservation. The median age at diagnosis was 11.1 years and at the time of procedure it was 13 years, respectively. Twenty-four patients were not pubertal at the time of storage, whereas 23 patients had already experienced menarche. The median time between laparoscopy and HSCT was 25 days. Twenty-six out of 28 evaluable patients (93%) developed hypergonadotropic hypogonadism at a median time of 23.3 months after HSCT. One patient required autologous orthotopic transplantation that resulted in one live birth. Results show a very high rate of iatrogenic hypergonadotropic hypogonadism, highlighting the need for fertility preservation in these patients.

Fertility preservation in women with cancer

Enhanced long-term survival rates of young women with cancer and advances in reproductive medicine and cryobiology have culminated in an increased interest in fertility preservation methods in girls and young women with cancer. Present data suggest that young patients with cancer should be referred for fertility preservation counselling quickly to help with their coping process. Although the clinical application of novel developments, including oocyte vitrification and oocyte maturation in vitro, has resulted in reasonable success rates in assisted reproduction programmes, experience with these techniques in the setting of fertility preservation is in its infancy. It is hoped that these and other approaches, some of which are still regarded as experimental (eg, ovarian tissue cryopreservation, pharmacological protection against gonadotoxic agents, in-vitro follicle growth, and follicle transplantation) will be optimised and become established within the next decade. Unravelling the complex mechanisms of activation and suppression of follicle growth will not only expand the care of thousands of women diagnosed with cancer, but also inform the care of millions of women confronted with reduced reproductive fitness because of ageing.

Autotransplantation of cryopreserved ovarian tissue--effective method of fertility preservation in cancer patients

OBJECTIVE

To review the literature and to present the latest advances in the autotransplantation of cryopreserved ovarian tissue.

MATERIALS AND METHODS

A literature review was conducted for all relevant articles assessing the fertility preservation, ovarian tissue transplantation, standard freezing and vitrification of ovarian tissue.

RESULTS

One of the promising and effective methods for fertility preservation may be the autotransplantation of cryopreserved ovarian tissue. At present, 30 babies have been born after orthotopic autotransplantation of frozen-thawed human ovarian tissue. Restoration of ovarian activity occurs between 3.5 months and 6.5 months. The longevity of autotransplanted ovarian tissue is about 5-7 years. The follicles are similarly preserved after all freezing methods; however, the ovarian stroma is significantly better preserved after vitrification than after slow freezing. An important topic for further research is preparation of the "vascular bed", optimization of vitrification technique and the development of alternative procedures to avoid the transmission of cancer cells via ovarian tissue autotransplantation - "artificial ovary".

CONCLUSIONS

Cryopreservation of ovarian tissue has unique advantages over other strategies. This method: (1) does not delay cancer treatment; (2) is safer for hormone dependent malignancy; (3) can be done independent of menstrual cycles; (4) is the only option for prepubertal girls; (5) can restore not only fertility but endocrine function.

Autotransplantation of cryopreserved ovarian tissue in oncological patients: recovery of ovarian function

ABSTRACT: 

Aim: To present preliminary results of autotransplantation of cryopreserved ovarian tissue performed at Sant’Orsola-Malpighi Hospital, Bologna, Italy. Materials & methods: Orthotopic transplantation was performed in two women with colorectal and breast cancer, and heterotopic transplantation was performed in one Hodgkin’s lymphoma woman. The presence of micrometastasis in the ovarian tissue was checked, and morphological features of ovarian tissue were evaluated before transplantation. Ovarian function was monitored by hormonal and ultrasound-color Doppler examination after transplantation. Results: In all three women, no micrometastasis was found; light and transmission electron microscopy showed well-preserved thawed ovarian tissue. Ovarian function recovery was observed 2–4 months after transplantation. Spontaneous menstrual cycles occurred in two women with normal follicular densities. No periods occurred in the woman with low follicular density at the time of tissue collection. Conclusion: Ovarian tissue cryopreservation and transplantation is a promising approach for preserving ovarian function in women with cancer.

Fertility in Turner syndrome

There is increasing interest in fertility and use of assisted reproductive technologies for women with Turner syndrome (TS). Current parenting options include adoption, surrogacy, and spontaneous and assisted reproduction. For women with TS, specific risks of pregnancy include higher than usual rates of spontaneous abortion, foetal anomaly, maternal morbidity and mortality. Heterologous fertility assistance using oocytes from related or unrelated donors is an established technique for women with TS. Homologous fertility preservation includes cryopreservation of the patient's own gametes prior to the progressive ovarian atresia known to occur: preserving either mature oocytes or ovarian tissue containing primordial follicles. Mature oocyte cryopreservation requires ovarian stimulation and can be performed only in postpubertal individuals, when few women with TS have viable oocytes. Ovarian tissue cryopreservation, however, can be performed in younger girls prior to ovarian atresia - over 30 pregnancies have resulted using this technique, however, none in women with TS. We recommend consideration of homologous fertility preservation techniques in children only within specialized centres, with informed consent using protocols approved by a research or clinical ethics board. It is essential that further research is performed to improve maternal and foetal outcomes for women with TS.

Autotransplantation of cryopreserved ovarian tissue in cancer survivors and the risk of reintroducing malignancy: a systematic review

BACKGROUND The risk of recurrent oncological disease due to the reintroduction of cancer cells via autotransplantation of cryopreserved ovarian tissue is unknown. METHODS A systematic review of literature derived from MEDLINE, EMBASE and the Cochrane Library was conducted. Studies on follow-up after autotransplantation; detection of cancer cells in ovarian tissue from oncological patients by histology, polymerase chain reaction or xenotransplantation; and epidemiological data on ovarian metastases were included. RESULTS A total of 289 studies were included. Metastases were repeatedly detected in ovarian tissue obtained for cryopreservation purposes from patients with leukaemia, as well as in one patient with Ewing sarcoma. No metastases were detected in ovarian tissue from lymphoma and breast cancer patients who had their ovarian tissue cryopreserved. Clinical studies indicated that one should be concerned about autotransplantation safety in patients with colorectal, gastric and endometrial cancer. For patients with low-stage cervical carcinoma, clinical data were relatively reassuring, but studies focused on the detection of metastases were scarce. Oncological recurrence has been described in one survivor of cervical cancer and one survivor of breast cancer who had their ovarian tissue autotransplanted, although these recurrences may not be related to the transplantation. CONCLUSIONS It is advisable to refrain from ovarian tissue autotransplantation in survivors of leukaemia. With survivors of all other malignancies, current knowledge regarding the safety of autotransplantation should be discussed. The most reassuring data regarding autotransplantation safety were found for lymphoma patients.

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.

The safety of transplanting cryopreserved ovarian tissue in cancer patients: a review of the literature

BACKGROUND

Transplantation of frozen/thawed ovarian tissue from patients with a malignant condition is associated with a risk of re-introduction of the disease as the tissue usually is removed before anti-cancer therapy and may thus contain malignant cells. We review studies investigating the presence of malignant cells in cryopreserved ovarian tissue from patients with malignant disease and based on the strength of the evidence, recommendations for transplantations are proposed.

MATERIALS AND METHODS

A systematic review of the literature. All peer reviewed studies evaluating the presence of malignant cells in cryopreserved human ovarian tissue were included. Data were searched in Pubmed and Embase with no language restrictions.

RESULTS

The majority of the reviewed papers were casuistic reports and few of the included papers were specifically designed to search for malignant cells. Ovarian tissue from 422 patients has been subject to testing for malignant cells by imaging, histology, immunohistochemistry, molecular biology, animal- or clinical transplantation. In 31 (7 %) of the cases the applied test raised suspicion of malignant cell infiltration. No transplantation-related relapse of cancer has been reported after 33 transplantations of frozen/thawed ovarian cortex.

CONCLUSION

The quality and strength of the evidence is generally low and prospective studies are needed. The risk of re-introducing a malignant condition when transplanting ovarian tissue depends on the particular disease. Based on the available data, the risk was estimated: Leukaemia: HIGH. Gastrointestinal cancers: MODERATE. Breast cancer, sarcomas of the bone and connective tissue, gynaecological cancers, Hodgkin's and Non-Hodgkin's Lymphoma: LOW.

Cryopreservation of ovarian tissue in breast cancer patients: 10 years of experience

Aim: To present a decade of experience with ovarian tissue cryopreservation in breast cancer patients. Materials & methods: The safety of the procedure was histologically evaluated before and after freezing in 94 patients. Out of 94 patients, 48 prechemotherapy patients were randomly selected to determine stroma and follicle preservation and follicular density. Results: The ovarian tissue from 94 patients did not identify any micrometastases. After cryopreservation, morphology of the ovarian tissue and density of healthy follicles were similar in fresh and frozen tissue. Follicular density decreased with the increasing age of patients in both fresh and frozen tissue (p < 0.0001). A variation in follicular density was observed between fresh and frozen tissue (p < 0.05). Conclusion: These results suggest that ovarian tissue cryopreservation is highly feasible for preserving the fertility of young breast cancer patients.

Cryopreservation of ovarian tissue for fertility preservation in young female oncological patients

Girls and women suffering from a cancer that requires treatment with gonadotoxic drugs may experience cessation of reproductive function as a side effect due to obliteration of the ovarian pool of follicles. Techniques are now available for fertility preservation, such as cryopreservation of mature oocytes, embryos or ovarian cortical tissue. Whereas collection of mature oocytes and embryos requires at least a 2-week period, ovarian tissue may on short notice be frozen prior to treatment and can be transplanted back into women with ovarian failure. Transplanted frozen/thawed tissue supports survival and growth of follicles, giving rise to menstrual cycles and hormone production for several years. Worldwide, the procedure has resulted in the birth of 15 healthy children. Many cancer patients including girls and young women want fertility preservation, and the techniques are now being further developed and implemented in several centers.

Applicability of adult techniques for ovarian preservation to childhood cancer patients

PURPOSE

To appraise the feasibility of current adult medical and surgical techniques for ovarian preservation in pre-pubertal and adolescent girls with cancer.

METHODS

Literature search using PubMed and SCOPUS up to February 2012. In addition, the reference lists of selected studies and all identified systematic and narrative reviews were scanned for relevant references. Inclusion criteria were ovarian preservation and cancer. Exclusion criteria were non-English publications, letters, personal communications, and ovarian preservation for conditions other than cancer.

RESULTS

Data from the selected publications was interpreted and discussed in the relevant sections. Cryopreservation of ovarian tissue followed by autologous transplant represents the only surgical option available for pre-pubertal girls and adolescents who cannot delay the start of chemotherapy. Few studies report on pre-pubertal and adolescent girls undergoing ovarian preservation surgeries with good harvesting, and no follow-up has been conveyed, to date. Outcomes of ovarian function after ovarian suppression with GnRH-analogs in adults have been controversial and no reports are available for pre-pubertal girls.

CONCLUSIONS

Autologous transplantation of cryopreserved ovarian cortex probably represents the best option for preservation of fertility and hormonal function in childhood cancer females; however, future research needs to address the safety of this technique, especially in patients with blood-borne cancers. Ovarian suppression with GnRH-analogs at the time of chemotherapy treatment has not proven to be superior to non-suppression for fertility preservation purposes in adults. Not enough evidence is presently available in childhood cancer patients.

Assessment of long term endocrine function after transplantation of frozen-thawed human ovarian tissue to the heterotopic site: 10 year longitudinal follow-up study

PURPOSE

To assess the longevity of ovarian grafts in five cancer patients who underwent heterotopic autotransplantation of frozen-thawed ovarian tissue.

METHOD(S)

Five cancer survivors underwent heterotopic ovarian transplantation between 2001 and 2011. Stored ovarian tissue (for 1-10 years) was rapidly thawed and transplanted into the space between the rectus sheath and the rectus muscle (8-20 cortical sections per patient). Endocrine function was assessed by monthly blood tests (FSH, LH, E2, progesterone and testosterone) and ultrasound after transplantation. The monitoring was continued until the cessation of endocrine function by consecutive blood tests (E2 < 20 pg/ml; FSH ≥ 35 IU/L).

RESULT(S)

Endocrine function was restored in all patients between 12-20 weeks after transplantation. Four patients required the second transplantation one to two years after the first transplantation. The duration of endocrine function after the second transplantation was much longer (9 months-84 months). The longest duration of endocrine function was seen in a woman who underwent ovarian transplantation in 2003 and 2004 after radiotherapy for cervical cancer. Even more than seven years after transplantation, endocrine function has not ceased (FSH 9.5, E2 108, on July 1, 2011). Of note, this patient underwent three IVF cycles in 2004 which resulted in four embryos.

CONCLUSION(S)

Long-term endocrine function lasting for seven years can be established with heterotopic transplantation of cryobanked human ovarian tissue. Re-establishment of long-term endocrine function after ovarian transplantation will benefit young cancer survivors with premature ovarian failure.

Evaluation of the ovarian reserve in women transplanted with frozen and thawed ovarian cortical tissue

OBJECTIVE

To investigate ovarian reserve and ovarian function in women transplanted with frozen/thawed ovarian tissue.

DESIGN

Retrospective cohort study.

SETTING

University hospital.

PATIENT(S)

18 women transplanted with their own frozen/thawed ovarian tissue.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Levels of antimüllerian hormone (AMH), duration of function of the transplanted ovarian tissue, outcome of assisted reproduction.

RESULT(S)

Of the 18 women who received transplanted ovarian tissue, levels of AMH were measured in 12 women; AMH never exceed a concentration of 1 ng/mL, and in several cases they were below the detection limit of the assay in combination with regular menstrual cycles. Two women with AMH below the detection limit conceived spontaneously. The duration of function of the transplants was between 9 months and 7 years and still functioning. Twelve women received assisted reproduction therapy; in 72 cycles, 65 oocytes were retrieved. The pregnancy rate and live-birth rate per cycle were 6.9% (5 of 72) and 2.8% (2 of 72), respectively.

CONCLUSION(S)

The relatively poor outcome of assisted reproduction in women transplanted with frozen/thawed ovarian tissue may reflect reduced follicular selection rather than defective or aged oocytes. In normal women, reduced follicular selection with age may be part of explaining the decline in female fecundity with increasing age.