Fertility preservation for women with breast cancer before chemotherapy: a systematic review and meta-analysis

Exploring stem cell technology: Pioneering new pathways for female fertility preservation and restoration

The fertility of women is crucial for the well-being of individuals and families. However, various factors such as chemotherapy, lifestyle changes, among others, may lead to a decline in female fertility, thus emphasizing the significance of preserving and restoring fertility. Stem cells, with their unique capacity for self-renewal and pluripotent differentiation, have made significant strides in areas such as ovarian tissue cryopreservation, in vitro culture of frozen-thawed ovarian tissue, and construction of ovarian-like organs. This review aims to summarize the latest findings in these fields, highlighting the pivotal role, mechanisms, and future prospects of stem cell technology in preserving and restoring female fertility. Additionally, the importance of interdisciplinary collaboration is underscored, as personalized stem cell therapy regimens tailored through interdisciplinary cooperation between reproductive medicine and stem cell fields hold promise in providing reliable solutions for the preservation and restoration of female fertility.

Gynotoxic Effects of Chemotherapy and Potential Protective Mechanisms

Chemotherapy is one of the leading cancer treatments. Unfortunately, its use can contribute to several side effects, including gynotoxic effects in women. Ovarian reserve suppression and estrogen deficiency result in reduced quality of life for cancer patients and are frequently the cause of infertility and early menopause. Classic alkylating cytostatics are among the most toxic chemotherapeutics in this regard. They cause DNA damage in ovarian follicles and the cells they contain, and they can also induce oxidative stress or affect numerous signaling pathways. In vitro tests, animal models, and a few studies among women have investigated the effects of various agents on the protection of the ovarian reserve during classic chemotherapy. In this review article, we focused on the possible beneficial effects of selected hormones (anti-Müllerian hormone, ghrelin, luteinizing hormone, melatonin), agents affecting the activity of apoptotic pathways and modulating gene expression (C1P, S1P, microRNA), and several natural (quercetin, rapamycin, resveratrol) and synthetic compounds (bortezomib, dexrazoxane, goserelin, gonadoliberin analogs, imatinib, metformin, tamoxifen) in preventing gynotoxic effects induced by commonly used cytostatics. The presented line of research appears to provide a promising strategy for protecting and/or improving the ovarian reserve in the studied group of cancer patients. However, well-designed clinical trials are needed to unequivocally assess the effects of these agents on improving hormonal function and fertility in women treated with ovotoxic anticancer drugs.

Survey on the implementation status and reproductive outcomes of oocyte and ovarian tissue cryopreservation in Japan: Historical comparison with nationwide surveys

PURPOSE

To clarify the reproductive outcomes of fertility preservation (FP) treatment.

METHODS

We conducted a mailed-in questionnaire survey at institutions certified by the Japan Society of Obstetrics and Gynecology to investigate the number of oocyte cryopreservations (OC) and ovarian tissue cryopreservations (OTC) performed from December 2016 to the end of 2020. And, we conducted a detailed investigation of cases in which frozen specimens were used during the investigation period, and made historical comparisons with previous nationwide studies.

RESULTS

Responses were received from 114 out of 150 facilities (response rate: 76.0%) for OC and 43 out of 51 for OTC (response rate: 84.3%). Breast cancer was the most common disease among patients whose FP specimens were used. During the study period, 1237 OCs and 198 OTCs were performed. In addition, 57 cycles of embryo transfer (ET) using cryopreserved oocytes and 12 cases of ovarian tissue transplantation (OTT) were performed. The mean age of patients who underwent ET using cryopreserved oocytes was 34.8 (±5.8) years, with a median age of 36 years. The pregnancy rate per ET using cryopreserved oocytes was 26.3% and the live birth rate (LBR) was 17.5%. Further, the LBR per patient was 43.3%, and the pregnancy rate following OTTs was 33.3%. Also, controlled ovarian stimulation using the random start method or the combination of aromatase inhibitors had no effect on pregnancy outcome.

CONCLUSION

Implementation of both OCs and OTCs have markedly increased over time in Japan, with comparable reproductive outcomes as other reports.

The Usage of Cryopreserved Reproductive Material in Cancer Patients Undergoing Fertility Preservation Procedures

BACKGROUND

Many cancer treatment methods can affect fertility by damaging the reproductive organs and glands that control fertility. Changes can be temporary or permanent. In order to preserve the fertility of cancer patients and protect the genital organs against gonadotoxicity, methods of fertility preservation are increasingly used. Considering that some patients ultimately decide not to use cryopreserved reproductive material, this review analysed the percentage of post-cancer patients using cryopreserved reproductive material, collected before treatment as part of fertility preservation.

METHODS

A systematic search of studies was carried out in accordance with the Cochrane Collaboration guidelines, based on a previously prepared research protocol. The search was conducted in Medline (via PubMed), Embase (via OVID), and the Cochrane Library. In addition, a manual search was performed for recommendations/clinical practice guidelines regarding fertility preservation in cancer patients.

RESULTS

Twenty-six studies met the inclusion criteria. The studies included in the review discussed the results of cryopreservation of oocytes, embryos, ovarian tissue, and semen. In 10 studies, the usage rate of cryopreserved semen ranged from 2.6% to 21.5%. In the case of cryopreserved female reproductive material, the return/usage rate ranged from 3.1% to 8.7% for oocytes, approx. 9% to 22.4% for embryos, and 6.9% to 30.3% for ovarian tissue. In studies analysing patients' decisions about unused reproductive material, continuation of material storage was most often indicated. Recovering fertility or death of the patient were the main reasons for rejecting cryopreserved semen in the case of men.

CONCLUSION

Fertility preservation before gonadotoxic treatment is widely recommended and increasingly used in cancer patients. The usage rate is an important indicator for monitoring the efficacy of these methods. In all of the methods described in the literature, this indicator did not exceed 31%. It is necessary to create legal and organizational solutions regulating material collection and storage and to create clear paths for its usage in the future, including by other recipients.

Outcomes and cost-effectiveness comparisons of progestin-primed ovarian stimulation, GnRH antagonist protocol, and luteal phase stimulation for fertility preservation

OBJECTIVE

To compare the clinical outcomes and cost-effectiveness of progestin-primed ovarian stimulation (PPOS) and the gonadotropin-releasing hormone-antagonist (GnRH-A) protocol in fertility preservation (FP) in cancer patients. The stimulation option when patients were in the luteal phase was also explored.

METHODS

This retrospective study analyzed clinical data from 163 patients who underwent FP. The number of retrieved oocytes and vitrified oocytes/embryos, total dose of gonadotropin, duration of stimulation, number of injections, and cost were compared among the PPOS, GnRH-A, and luteal phase stimulation (LPS) groups.

RESULTS

No significant differences were noted in the numbers of retrieved oocytes and vitrified oocytes/embryos among the three groups. In the multiple regression model, age (P = 0.02) and antral follicle count (AFC) (P < 0.001), but not the controlled ovarian stimulation (COS) protocols (P = 0.586), were associated with the number of retrieved oocytes. The number of injections and the cost were all significantly lower in the PPOS and LPS groups than in the GnRH-A group(P < 0.001).

CONCLUSION

PPOS had similar clinical results but was superior medically and economically to GnRH-A. For patients in the luteal phase, LPS was an optional protocol with similar outcomes and costs to PPOS.

Cryostorage of human ovarian tissue: evaluating the storage and disposal pattern over a 22-year period in 2475 patients

RESEARCH QUESTION

What are the parameters of age, indications for ovarian tissue cryopreservation, storage characteristics and reasons for tissue disposal in a large cohort of individuals undertaking cryopreservation?

DESIGN

The relevant parameters in a single university centre were revised and digitalized in the period from 2019 to 2021. To assess patients' motivation at the end of storage, patients were contacted by letter, e-mails and telephone calls.

RESULTS

A group of 2475 patients with stored ovarian tissue were analysed in the time period between 2000 and 2021; the response rate for contact calls and letters was 28.8% (224/777). Where storage had ended (n = 1155), patients had on average stored for 3.8 years and begun storing at age 30 years; the main indications were breast cancer (53%) and lymphoma (17.5%). Of these participants, 2.5% had a transplantation on site, 10.3% transferred their tissue to another cryobank and 11.5% were deceased. The majority of the group (75.7%) ended their storage due to pregnancy (49.1%), a lack of desire to have children (25.9%), storage fees that were too expensive (8.9%), death (8.5%), recurrence of cancer (8.5%), lack of a partner (4%) and fear of surgery in the future (3.1%); 6.7% retrospectively regretted ending storage.

CONCLUSIONS

The pregnancy rate of 49.1%, resulting from ovarian tissue that was not removed during surgery for scheduled ovarian tissue cryopreservation supports the clinical approach of removing and cryopreserving only 25-50% of one ovary. It is proposed that interdisciplinary counselling should be implemented not only prior to fertility preservation, but also when intending to end storage.

Double stimulation for the management of poor-prognosis patients: where are we going?

PURPOSE OF REVIEW

The technical improvements in IVF allowed the implementation of nonconventional ovarian stimulation protocols for some specific patients. Where time is crucial, such as with oncologic patients, poor-prognosis patients, patients with low ovarian reserve, and those with advanced maternal age, access to IVF treatment is even more critical. Some of these protocols might start in the late follicular phase, luteal phase, or involve both stimulations within the same ovarian cycle.

RECENT FINDINGS

Until now, published evidence showed that oocytes retrieved from unconventional protocol seem to be developmentally, genetically, and reproductively competent. Second stimulation in the same ovarian cycle after the conventional approach may represent a sound alternative to oocyte accumulation. This can be proposed in progress after careful counselling focused on the patients' chances of finding at least one euploid embryo on account of their age and of the number of blastocysts obtained after the conventional approach.

SUMMARY

The adoption of these new strategies, known as double stimulation protocol, can be conceived as a real full-personalization of ovarian stimulation. Multicentre prospective RCTs are urgently needed to evaluate the efficacy, efficiency, and costs of double stimulation versus two consecutive conventional approaches with standard or mild stimulation and in a different IVF setting.

Fertility Preservation Techniques in Neuro-Oncology Patients: Protocol for a Systematic Review

BACKGROUND

Advancements in cancer treatments have successfully improved central nervous system (CNS) cancer survivorship and overall quality of life. As a result, the awareness of the importance of fertility preservation techniques is increasing. Currently, a range of established techniques, such as oocyte cryopreservation and sperm cryopreservation, are available. However, oncologists may be hesitant to refer patients to a reproductive specialist.

OBJECTIVE

The primary aim of the proposed systematic review is to assess the best evidence for fertility preservation techniques used in patients with CNS cancers. It also aims to evaluate outcomes related to their success and complications.

METHODS

This protocol was produced in adherence with the PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols). Electronic databases will be systematically searched to identify studies that meet our eligibility criteria. Studies will be included if they report at least one type of fertility preserving or sparing technique in male patients of any age and female patients aged <35 years. Animal studies, non-English studies, editorials, and guidelines will be excluded from the review. From the included studies, data will be extracted and synthesized by using a narrative approach and summarized in tables. The primary outcome will be the number of patients successfully undergoing a fertility preservation technique. The secondary outcomes will include the number of retrieved oocytes, the number of oocytes or embryos vitrified for cryopreservation, clinical pregnancy, and live birth. The quality of the included studies will be assessed by using the National Heart, Lung, and Blood Institute risk-of-bias tool for any type of study.

RESULTS

The systematic review is expected to be completed by the end of 2023, and results will be published in a peer-reviewed journal and on PROSPERO.

CONCLUSIONS

The proposed systematic review will summarize the fertility preservation techniques available for patients with CNS cancers. Given the improvement in cancer survivorship, it is becoming increasingly important to educate patients about fertility preservation techniques. There are likely to be several limitations to this systematic review. Current literature is likely to be of low quality due to insufficient numbers, and there may be difficulty in accessing data sets. However, it is our hope that the results from the systematic review provide an evidence base to help inform the referral of patients with CNS cancers for fertility preservation treatments.

TRIAL REGISTRATION

PROSPERO CRD42022352810; https://tinyurl.com/69xd9add.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/44825.

Maximize the safety and efficacy of fertility preservation by random start/dual ovarian stimulation for early breast cancer patients

OBJECTIVE

What is the more efficient and safer protocol during controlled ovarian hyperstimulation (COH) for early-stage breast cancer patients seeking emergency fertility preservation before adjuvant chemo/radiotherapy?

MATERIALS AND METHODS

This retrospective, case-series study involved two early-stage (Ia) breast cancer patients that requested for fertility preservation within 3 weeks. Random start/dual stimulation protocols with aromatase inhibitor (AI) were used to maximize oocyte yield and suppress serum estradiol (E2) level.

RESULTS

E2 levels on trigger day during dual COH were between 112.0 and 407.0 pg/mL. Duration of COH could be shortened to only 17 days, and up to 41 oocytes were successfully retrieved with two retrievals.

CONCLUSION

This remarkable efficient and safe protocol involves the combination of random start/dual stimulation with step-up AI dosage beforehand which not only maximize oocyte yield within the shortest possible timeframe, but also to maintain the low level of E2 to avoid over-stimulating estrogen-sensitive cancer cells and to decrease the risk of developing ovarian hyperstimulation syndrome (OHSS).