Oocyte cryostorage to preserve fertility in oncological patients

Chronic kidney disease, female infertility, and medically assisted reproduction: a best practice position statement by the Kidney and Pregnancy Group of the Italian Society of Nephrology

Fertility is known to be impaired more frequently in patients with chronic kidney disease than in the general population. A significant proportion of chronic kidney disease patients may therefore need Medically Assisted Reproduction. The paucity of information about medically assisted reproduction for chronic kidney disease patients complicates counselling for both nephrologists and gynaecologists, specifically for patients with advanced chronic kidney disease and those on dialysis or with a transplanted kidney. It is in this context that the Project Group on Kidney and Pregnancy of the Italian Society of Nephrology has drawn up these best practice guidelines, merging a literature review, nephrology expertise and the experience of obstetricians and gynaecologists involved in medically assisted reproduction. Although all medically assisted reproduction techniques can be used for chronic kidney disease patients, caution is warranted. Inducing a twin pregnancy should be avoided; the risk of bleeding, thrombosis and infection should be considered, especially in some categories of patients. In most cases, controlled ovarian stimulation is needed to obtain an adequate number of oocytes for medically assisted reproduction. Women with chronic kidney disease are at high risk of kidney damage in case of severe ovarian hyperstimulation syndrome, and great caution should be exercised so that it is avoided. The higher risks associated with the hypertensive disorders of pregnancy, and the consequent risk of chronic kidney disease progression, should likewise be considered if egg donation is chosen. Oocyte cryopreservation should be considered for patients with autoimmune diseases who need cytotoxic treatment. In summary, medically assisted reproduction is an option for chronic kidney disease patients, but the study group strongly advises extensive personalised counselling with a multidisciplinary healthcare team and close monitoring during the chosen medically assisted reproduction procedure and throughout the subsequent pregnancy.

Human recombinant FSH induces chemoresistance in human breast cancer cells via HIF-1α activation†

Breast cancer patients under 40 years of age who are candidate to chemotherapy with alkylating drugs may undergo controlled ovarian stimulation (COS) with recombinant human follicle-stimulating hormone (rhFSH) in order to get fertility preservation by mature oocyte cryostorage. The direct effect(s) of exogenous rhFSH on the chemosensitivity of breast cancer is currently unknown. To clarify this issue, we incubated four different breast cancer cell lines with rhFSH (10 IU/L, 24 h) and then we exposed them to doxorubicin (DOX) or cyclophosphamide (CPA). The effect(s) of rhFSH on human breast cancer cells treated with DOX or CPA was measured in terms of (1) cell viability, (2) cytotoxicity, (3) multidrug resistance (MDR) genes and proteins expression and activities, and (4) hypoxia-inducible factor 1-alpha (HIF-1α) activation. Pretreatment with rhFSH significantly increased the viability of breast cancer cells after treatment with DOX or CPA, and reduced the lactate dehydrogenase leakage and reactive oxygen species production. Moreover, after preincubation with rhFSH, the MDR proteins (Pgp, MPR1, and BCRP) expression and activity resulted upregulated and the HIF-1α pathway activated. In addition, the use of a widely used HIF-1α inhibitor, the 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1), prevented the rhFSH effect on the onset of MDR. Taken together, these observations suggest that a short exposure to rhFSH induces chemoresistance to DOX and CPA in human breast cancer cells via HIF-1α activation.

Is the pre-antral ovarian follicle the 'holy grail'for female fertility preservation?

Fertility preservation is not only a concern for humans with compromised fertility after cancer treatment. The preservation of genetic material from endangered animal species or animals with important genetic traits will also greatly benefit from the development of alternative fertility preservation strategies. In humans, embryo cryopreservation and mature-oocyte cryopreservation are currently the only approved methods for fertility preservation. Ovarian tissue cryopreservation is specifically indicated for prepubertal girls and women whose cancer treatment cannot be postponed. The cryopreservation of pre-antral follicles (PAFs) is a safer alternative for cancer patients who are at risk of the reintroduction of malignant cells. As PAFs account for the vast majority of follicles in the ovarian cortex, they represent an untapped potential, which could be cultivated for reproduction, preservation, or research purposes. Vitrification is being used more and more as it seems to yield better results compared to slow freezing, although protocols still need to be optimized for each specific cell type and species. Several methods can be used to assess follicle quality, ranging from simple viability stains to more complex xenografting procedures. In vitro development of PAFs to the pre-ovulatory stage has not yet been achieved in humans and larger animals. However, in vitro culture systems for PAFs are under development and are expected to become available in the near future. This review will focus on recent developments in (human) fertility preservation strategies, which are often accomplished by the use of in vitro animal models due to ethical considerations and the scarcity of human research material.

NMR metabolomics study of follicular fluid in women with cancer resorting to fertility preservation

PURPOSE

The purpose of this study was to evaluate the possible application of metabolomics to identify follicular fluid changes in cancer patients undergoing fertility preservation. Although metabolomics have been applied already in cancer studies, this is the first application on follicular fluid of cancer patients.

METHODS

We selected for the study ten patients with breast cancer and lymphoma who resorted to oocyte cryopreservation to preserve fertility and ten healthy women undergoing in vitro fertilization treatments. Follicular fluid was collected at the time of oocytes retrieval. Metabolomic analysis of follicular fluids was performed by 1H-nuclear magnetic resonance (NMR) spectroscopy in combination with multivariate analysis to interpret the spectral data. Univariate statistical analysis was applied to find correlations between patients' features and metabolites identified by NMR.

RESULTS

Partial least squares discriminant analysis allowed to discriminate samples from cancer patients and healthy controls. Univariate statistical analysis found significant correlations between patients' features and metabolites identified by NMR. This finding allowed to identify biomarkers to differentiate both healthy controls from cancer patients and the two different classes of oncological patients.

CONCLUSION

The follicular fluids of cancer patients display significant metabolic alterations in comparison to healthy subjects. NMR-based metabolomics could be a valid prognostic tool for identifying and selecting the best cryopreserved oocytes and improving the outcome prediction in cancer women undergoing in vitro fertilization.

Effects of vitrification on the viability of alginate encapsulated isolated bovine pre-antral follicles

PURPOSE

Individual follicle cryopreservation techniques, without hydrogel support, are labor-intensive and a substantial proportion of isolated follicles are lost during handling and after warming. Therefore, the viability and morphology of isolated bovine (as a model for human) pre-antral follicles after vitrification and warming, when encapsulated in alginate beads, were investigated.

METHODS

Bovine pre-antral follicles were mechanically isolated and divided into four different groups: (1) culture in 2% alginate beads (3D system) and vitrification in beads using mesh cups (3DVIT), (2) culture in 2% alginate beads (3DCUL), (3) culture in 96-well plates (2D system) and vitrification using High Security Vitrification straws® (2DVIT), (4) culture in a 2D system (2DCUL). The same vitrification and warming protocols were used for embedded (3DVIT) and non-embedded follicles (2DVIT).

RESULTS

No differences were observed in follicle viability between group 2DCUL and 3DCUL. Group 3DVIT showed the lowest viability (45.9%) according to calcein and neutral red staining among all groups. Group 2DVIT displayed the highest viability (87.5%) and largest percentage of follicles with a well-preserved morphology.

CONCLUSIONS

Our results show that, using a vitification protocol optimized for non-embedded follicles, 2D culture is more effective in vitrifying isolated follicles. However, embedding in alginate allow to handle follicles more efficiently, i.e., without excessive manipulation and thus less labor-intensive in combination with a reduced loss of follicles during the procedure. Based on the increased work efficiency, but lower viability and higher proportion of follicles showing impaired morphology, we consider it advantageous to optimize the protocol for the vitrification of embedded follicles to increase survival and maintain morphology after vitrification.

Triptorelin for Fertility Preservation in Adolescents Treated With Chemotherapy for Cancer

BACKGROUND

Triptorelin, a gonadotropin releasing hormone analogue, can be administered to postpubertal female individuals with cancer who receive chemotherapy to obtain menstrual suppression and decrease the risk of hemorrhage caused by thrombocytopenia. Our goal was to assess whether triptorelin also has a protective role against the gonadotoxicity of chemotherapy.

PATIENTS AND METHODS

This retrospective observational study includes all postmenarchal female patients who presented to our Unit from 2000 to 2015 and received chemotherapy for cancer. They were administered depot triptorelin. We evaluated long-term ovarian function in order to detect clinical signs of ovarian damage, miscarriages, and pregnancies. Laboratory follow-up consisted in dosing serum follicle stimulating hormone, luteinizing hormone, prolactin, estradiol, and progesterone. Ultrasound of the ovaries was performed as well.

RESULTS

Of 36 evaluable patients, 9 received hematopoietic stem cell transplantation (HSCT). The remaining 27 patients maintained normal ovarian function at clinical, laboratory, and ultrasound assessment. Five of them achieved spontaneous physiological pregnancy. Four of the 9 patients who underwent HSCT developed premature ovarian failure.

CONCLUSION

Our study suggests that gonadotropin releasing hormone-a administered during chemotherapy can prevent premature ovarian failure in patients treated without HSCT and that it is not enough to preserve the ovarian function during HSCT. Hence, a prospective randomized trial with a larger population would be recommended.

Fertility Preservation in Cancer Patients: In Vivo and In Vitro Options

Oocyte, embryo and ovarian tissue cryopreservation are being increasingly proposed for fertility preservation among cancer patients undergoing therapy to enable them to have babies after the cancer is cured. Embryo cryopreservation is not appropriate for single girls without any sperm partner and also because oocyte retrieval is an extended procedure, it is impossible in cases requiring immediate cancer cure. Thus ovarian tissue cryopreservation has been suggested for fertility preservation especial in cancer patients. The main goal of ovarian cryopreservation is re-implanting the tissue into the body to restore fertility and the hormonal cycle. Different cryopreservation protocols have been examined and established for vitrification of biological samples. We have used Cryopin to plunge ovarian tissue into the liquid nitrogen and promising results have been observed. Ovarian tissue re-implantation after cancer cure has one problem- the possibility of recurrence of malignancy in the reimplanted tissue is high. Xenografting-implantation of the preserved tissue in another species- also has its drawbacks such as molecular signaling from the recipient. In vitro follicle culturing is a safer method to obtain mature oocytes for fertilization and the various studies that have been carried out in this area are reviewed in this paper.

Ethics of medical and nonmedical oocyte cryopreservation

PURPOSE OF REVIEW

To assess the effectiveness and ethical dimensions of oocyte cryopreservation for both medical and social indications.

RECENT FINDINGS

As more women are postponing motherhood for a variety of reasons, including lack of partner, for completing career plans and reaching financial stability, they are resorting to oocyte cryopreservation. To make informed choices, women rely on their primary care physicians (PCPs) for initial advice, but PCPs are not always fully prepared to discuss oocyte cryopreservation. Interestingly, there are mixed feelings among obstetricians/gynecologists on whether oocyte cryopreservation should be used for elective reasons, whereas it is fully supported for medical indications.

SUMMARY

Oocyte vitrification has become an established procedure for safeguarding future reproductive chances for medical reasons, and its use is progressively expanding. There is an urgent need in preparing future PCPs and obstetricians/gynecologists as to how to initiate discussions with their patients about elective oocyte banking consistent with fully respecting patient autonomy so as to facilitate informed decisions.

Special issues in fertility preservation for gynecologic malignancies

Gynecologic malignancies account for 1,09 million new cancer cases worldwide consisting of about 12% of tumors affecting female population. About 10% of all female cancer survivors are younger than 40 years of age. Since cancers affecting female genital organs are usually treated by radical surgery, chemotherapy or chemoradiation approaches that induce permanent damage of reproductive functions, the development of strategies for fertility preservation represent one of the most important goals for gynecologic oncology. In this scenario, the newly defined oncofertility discipline acquires increasing interest, offering patients maximal chances to make an adequate decision about future fertility, based on their oncologic diagnosis and prognosis. However, the majority of physicians do not pay particular attention to these issues, even if impressive progresses have been made in this field in the last decades. Possibly, it is due to the lack of strong evidences from clinical trials without an adequate number of cases to establish safety and efficacy of these procedures. In this review we will discuss the most recently debated options for fertility preservation in gynecologic oncology, highlighting issues and controversies related to oncofertility.

Slow-freezing versus vitrification for human ovarian tissue cryopreservation

PURPOSE

Ovarian tissue can be cryopreserved prior to chemotherapy using either the slow-freezing or the vitrification method; however, the data on the equality of the procedures are still conflicting. In this study, a comparison of the cryo-damage of human ovarian tissue induced by either vitrification or slow-freezing was performed.

METHODS

Ovarian tissue from 23 pre-menopausal patients was cryopreserved with either slow-freezing or vitrification. After thawing/warming, the tissue was histologically and immunohistochemically analyzed and cultured in vitro. During tissue culture the estradiol release was assessed.

RESULTS

No significant difference was found in the proportion of high-quality follicles after thawing/warming in the slow-freezing and vitrification group, respectively (72.7 versus 66.7 %, p = 0.733). Estradiol secretion by the ovarian tissue was similar between groups during 18 days in vitro culture (area-under-the-curve 5,411 versus 13,102, p = 0.11). Addition of Sphingosine-1-Phosphate or Activin A to the culture medium did not alter estradiol release in both groups. The proportion of Activated Caspase-3 or 'Proliferating-Cell-Nuclear-Antigen' positive follicles at the end of the culture period was similar between slow-freezing and vitrification.

CONCLUSION(S)

Slow-freezing and vitrification result in similar morphological integrity after cryopreservation, a similar estradiol release in culture, and similar rates of follicular proliferation and apoptosis after culture.

Ovarian response to controlled ovarian hyperstimulation in women with cancer is as expected according to an age-specific nomogram

PURPOSE

To evaluate the ovarian response to controlled ovarian hyperstimulation (COH) in cancer patients according to an age-specific nomogram for the number of retrieved oocytes.

METHODS

Retrospective observational study carried out in a University affiliated fertility clinic. Forty-eight patients with cancer underwent ovarian stimulation for oocyte cryopreservation. An age - specific nomogram for the number of retrieved oocytes was built with 1536 IVF cycles due to male factor exclusively, oocyte donation and age related fertility preservation. The number of oocytes retrieved in cancer patients was compared to the expected response according to the nomogram using the Z-score.

RESULTS

The mean number of total retrieved oocytes in patients with cancer was 14.04 ± 8.83. After applying the Z-score to compare the number of retrieved oocytes between women with cancer and the expected response according to the age-specific nomogram, we did not observe a statistically significant difference (Z-score 0.23; 95 % CI [-0.13-0.60]).

CONCLUSION(S)

According to our results, patients with cancer exhibit an ovarian response as expected by age. Despite the limitation of the sample size, the obtained results should encourage oncologists for early referral of women with cancer to fertility specialists.

Maintaining the reproductive potential of cancer patients during cancer treatment

Cancer therapies are known to alter the reproductive potential in cancer patients. Due to improved survival rates in cancer patients of reproductive age, considerations of the long-term effects of cancer therapy have become more significant. Oncofertility is a new discipline in medicine that deals with maintaining the reproductive potential of cancer patients while they are receiving gonadotoxic cancer treatment. The purpose of this review is to explore how cancer treatment impairs reproductive functioning and present the current options for preservation of fertility in women. All patients with reproductive potential should be made aware of the possible treatment-related infertility and be offered appropriate fertility preservation options before cancer treatment is instituted. The hope is that, in the future, mechanism(s) can be developed to preserve immature germ cells in the ovary, so that they can be used for fertilization in vivo or in vitro.

Is letrozole needed for controlled ovarian stimulation in patients with estrogen receptor-positive breast cancer?

OBJECTIVE

To assess the advantages and disadvantages of using letrozole for controlled ovarian stimulation (COH) in young patients with estrogen receptor-positive (ER+) breast cancer, wishing to cryopreserve oocytes.

DESIGN

Retrospective cohort analysis.

SETTING

Sixteen Italian units for reproductive medicine and in vitro fertilization.

METHODS

Data of 50 ER+ breast cancer patients undergoing COH to cryopreserve oocytes before gonadotoxic chemotherapy with a letrozole plus gonadotropins (Le+Gn) protocol were compared with those of 25 young women with ER- breast cancer, submitted to COH using a protocol with gonadotropins alone (Gn-only).

RESULTS

The Le+Gn protocol implied a significantly lower total Gn consumption and allowed to maintain significantly lower circulating E2 levels at all checkpoints throughout stimulation (peak E2 value 446 ± 357 versus 1553 ± 908 pg/ml, respectively; p = 0.001). On the other side, the Le+Gn protocol allowed a significantly lower yield of oocytes available for cryostorage (6.6 ± 3.5 versus 8 ± 5, respectively; p = 0.038).

CONCLUSIONS

In breast cancer patients, the association of letrozole to Gn significantly reduces the number of oocytes available for cryostorage in comparison with the use of Gn alone. On the other side, it is associated with significantly lower E2 levels during the whole stimulation cycle, a safety issue that has been traditionally considered advantageous in case of ER+ cancers.