Cryopreservation of ovarian tissue for fertility preservation: no evidence of malignant cell contamination in ovarian tissue from patients with breast cancer

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.

Minimal residual disease detection of leukemic cells in ovarian cortex by eight-color flow cytometry

STUDY QUESTION

How can leukemic cells be detected in cryopreserved ovarian tissue?

SUMMARY ANSWER

Multicolor flow cytometry (FCM) is useful to evaluate the presence of viable leukemic cells in the ovarian cortex with a high specificity and a robust sensitivity.

WHAT IS KNOWN ALREADY

Storing ovarian tissue is an option to preserve fertility before gonadotoxic radiotherapy or chemotherapy treatments. However, transplantation of cryopreserved ovarian cortex to women cured of leukemia is currently not possible due to the risk of cancer re-seeding.

STUDY DESIGN, SIZE, DURATION

We developed an automated ovarian cortex dissociation technique and we used eight-color FCM to identify leukemic cells with a series of dilutions added to ovarian single cell suspensions obtained from healthy cortex.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

Healthy ovarian cortex originated from women between 23 and 39 years of age undergoing laparoscopic ovarian drilling for polycystic ovary syndrome. Blood or bone marrow cells were collected in acute lymphoblastic leukemia (ALL) patients at diagnosis.

MAIN RESULTS AND THE ROLE OF CHANCE

The tissue dissociation technique yield was 1.83 ± 1.49 × 10(6) viable nucleated cells per 100 mg of ovarian cortex. No cell exhibiting a leukemic phenotype was present in the normal ovarian cortex. Added leukemic cells were detected using their leukemia-associated phenotype up to a dilution of 10(-4). When specific gene rearrangements were present, they were detected by real-time quantitative PCR at the same dilution. The ovarian cortex from two leukemia patients was then used, respectively, as positive and negative controls.

LIMITATIONS, REASONS FOR CAUTION

Making available minimal residual disease (MRD) detection techniques (multicolor FCM, PCR and xenograft), that can be used either alone or together, is essential to add a fail-safe oncological dimension to pre-autograft monitoring.

WIDER IMPLICATIONS OF THE FINDINGS

This approach can be performed on fresh ovarian tissue during cryopreservation or on frozen/thawed tissue before reimplantation and it is currently the only available technique in cases of ALL where no molecular markers are identified. This new perspective should lead to studies on ovarian tissue from leukemia patients, for whom the presence of MRD should be established before autograft.

STUDY FUNDINGS/COMPETING INTEREST(S)

The study was supported by the BioMedicine Agency, the Committee of the League against Cancer, the Besançon University Hospital, DGOS/INSERM/INCa and the regional Council of Franche-Comté. There were no conflicts of interest to declare.

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.

Emergency IVF versus ovarian tissue cryopreservation: decision making in fertility preservation for female cancer patients

Hundreds of thousands of women in their reproductive years are diagnosed with cancer each year. As the number of female patients who survive cancer increases, the demand for effective and individualized fertility preservation options grows. Currently there are limited clinical options for fertility preservation, and the paucity of publications describing clinical experience and outcomes data has limited accessibility to these options. Decision making for patients diagnosed with cancer requires up-to-date knowledge of the efficacy and safety of available techniques. This article describes a step-by-step approach to evaluation of the cancer patient and presents an accumulation of clinical experience with challenges unique to patients with breast cancer and leukemia. Current data on reproductive outcomes of fertility preservation techniques are examined, demonstrating increasing evidence that these techniques are becoming effective enough to offer routinely to patients facing gonadotoxic cancer therapies, including those still considered to be "experimental."

A review of 15 years of ovarian tissue bank activities

PURPOSE

To review 15 years of activities in ovarian tissue cryobanking from medical database files, including patient indications, histological evaluation and clinical characteristics.

METHODS

Retrospective longitudinal analysis of data from an ovarian tissue bank in an academic hospital. Five hundred and eighty-two patients had their ovarian tissue cryobanked between April 1997 and January 2012. Analysis of cryobanking database: precryopreservation patient characteristics, indications and safety issues, laboratory files and postcryopreservation clinical data.

RESULTS

Of the 582 patients who had their ovarian tissue cryopreserved, 106 patients donated for research purposes and 476 patients for fertility preservation and long-term cryopreservation. Clinical data analysis of the 476 patients revealed a mean age at the time of cryopreservation of 23 ± 8.5 years (range: 9 months - 39 years), with 96.2 % of subjects aged ≤35 years (n = 458). Among 391 cases of malignant disease, hematological malignancies (39.9 %, n = 156) and breast cancer (21.7 %, n = 85) were the two main indications. At histology, malignant cells were found in ovarian tissue from leukemia patients (n = 3) and non-Hodgkin's lymphoma patients (n = 2). Eleven patients underwent autotransplantation, resulting in 5 live births and 1 ongoing pregnancy.

CONCLUSION

This is the largest and most comprehensive study to describe and analyze indications and clinical patient characteristics before and after ovarian tissue cryopreservation. The procedure is safe, easy and promising. The database concept is a useful tool in patient selection for autotransplantation.

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.

Female fertility loss and preservation: threats and opportunities

BACKGROUND

Ovarian aging and cytotoxic treatments are the most common causes for fertility loss in women. With increasing numbers of young female survivors following cytotoxic cancer treatments, the issue of fertility preservation has assumed greater importance.

METHODS

We review the literature on the causes of female fertility loss as well as the recent advances in fertility preservation options and strategies that might be of interest to oncologists. Currently, several methods and techniques exist for fertility preservation of female patients with cancer including embryo freezing, ovarian protection techniques, oocyte cryopreservation, ovarian tissue cryopreservation followed by autotransplantation, and recently in vitro culture of ovarian tissue, follicles, and oocytes. Each method or technique has advantages and disadvantages related to current success rate, required delay in cancer treatment, sperm requirement, and risk of reintroducing cancer cells.

RESULTS

To date, embryo freezing is the only established method successfully and widely used for fertility preservation of female patients with cancer. The other methods are promising but still considered experimental.

CONCLUSION

Patient awareness, physician knowledge, early counseling, costs management, international registry, interdisciplinary networks, and research development are necessary to improve the current care in the field of female fertility preservation.

[Ovarian cryopreservation: what future?]

Ovarian cortex cryobanking is a technique of fertility preservation that led to the birth of about 20 children in the world since 2004. Its main limitations are low follicular survival rate after thawing and transplantation and the risk of disease reintroduction. A lot of research is currently conducted in order to optimize both efficacy and safety of the graft and to develop alternative techniques to restore fertility. These advances will allow oncologists to offer this technique to a growing number of patients in the context of fertility preservation (for medical or social indications), but also in other indications such as puberty induction or menopause treatment.

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.

Spontaneous in vitro maturation of oocytes prior to ovarian tissue cryopreservation in natural cycles of oncologic patients

PURPOSE

To evaluate the recovery rate and spontaneous in vitro maturation (IVM) of immature oocytes enclosed within or released from follicles during the processing of ovarian tissue prior to its cryopreservation.

METHODS

Thirty-three oncologic patients who had not previously undergone chemo or radiotherapy underwent ovarian tissue cryopreservation (OTC) during natural menstrual cycles. Immature oocytes, enclosed within follicles or released during ovarian cortex processing, were collected and matured spontaneously in vitro for 48 h. Nuclear maturation was assessed every 24 h and the ability of the IVM oocytes to display a normal activation response following parthenogenetic activation was evaluated. The following outcome measures were also evaluated: disease, age, FSH, LH, E2, P4 and AMH serum levels, menstrual cycle day, recovery and spontaneous IVM and parthenogenetic activation rates.

RESULTS

Oocytes recovered per patient were 3.3 ± 0.7 (1.8-4.7 oocytes, 95CI), regardless of the menstrual phase. The mean number of IVM oocytes per patient was 1.3 ± 0.2 oocytes (95CI: 0.8-1.8), regardless of menstrual phase (p = 0.86) and oocyte origin (p = 0.61). Forty-one percent of oocytes extruded the second polar body and formed one pronucleus after parthenogenetic activation.

CONCLUSION

Twenty-one of the 33 women (63.6 %) requesting OTC produced at least one mature oocyte.

Long-term duration of function of ovarian tissue transplants: case reports

These three case reports describe the long-term duration of function of ovarian cortical tissue grafts among patients in a university fertility preservation programme in Europe and in a private practice programme in the USA. One woman underwent sterilizing cancer treatment and had frozen ovarian tissue transplanted, and two women underwent fresh ovarian tissue transplants. The function of ovarian cortical strips has continued for more than 7 years in these three women, with the birth of eight healthy babies following a single graft per patient. In addition to these three cases, transplantation (repeatedly in some cases) of cryopreserved ovarian tissue has restored reproductive function to all other women in the study centres' programmes for some years. The sustained longevity of function of the transplanted tissue suggests that it may also be possible to postpone the normal time of menopause or to alleviate its symptoms.

Safety of ovarian tissue autotransplantation for cancer patients

Cancer treatments can induce premature ovarian failure in almost half of young women suffering from invasive neoplasia. Cryopreservation of ovarian cortex and subsequent autotransplantation of frozen-thawed tissue have emerged as promising alternatives to conventional fertility preservation technologies. However, human ovarian tissue is generally harvested before the administration of gonadotoxic treatment and could be contaminated with malignant cells. The safety of autotransplantation of ovarian cortex remains a major concern for fertility preservation units worldwide. This paper discusses the main tools for detecting disseminated cancer cells currently available, their limitations, and clinical relevance.

Fertility preservation in girls and young women

There is increasing interest and experience in the options available to preserve fertility in those about to undergo potentially gonadotoxic chemotherapy or radiation therapy, usually related to treatment for cancer. Recent years have seen the development of methods for prepubertal girls, female adolescents and adult women, although these remain less established than sperm cryopreservation for men. At present, the options for prepubertal boys remain experimental. Embryo cryopreservation following ovarian stimulation and IVF is a routine procedure technically and its success in the management of infertility is established. However, there are no data on uptake or success rates in the context of fertility preservation in women with cancer. Oocyte cryopreservation is technically challenging and requires ovarian stimulation, thus potentially resulting in a delay in cancer treatment. Oocyte vitrification offers increased success rates in comparison with slow freezing; however, this approach is also limited by the number of oocytes that can be obtained. The third possibility, ovarian tissue cryopreservation, can be performed without significant delay and is the only option for prepubertal girls. Worldwide, a small number of children have been born following reimplantation of frozen/thawed ovarian tissue. It is clear that fertility preservation is important for some girls and young women facing treatments that will compromise their fertility, but the availability of all approaches varies widely. Effective approaches for prepubertal boys are also required.

Xenotransplantation of cryopreserved ovarian tissue from patients with ovarian tumors into SCID mice--no evidence of malignant cell contamination

This study examined the possible presence of malignant cells in ovarian cortex from patients with ovarian tumors after xenografting of the ovarian tissue into severe combined immunodeficiency mice. None of the mice presented symptoms of reintroduced malignancy nor did microscopic and immunohistochemical evaluation of the grafts raise any suspicion of residual malignant disease.