Methods of controlled ovarian stimulation for embryo/oocyte cryopreservation in breast cancer patients

Approaches to Fertility Preservation for Young Women With Breast Cancer

In patients with early breast cancer, the combination of different systemic treatment strategies, including chemotherapy, endocrine therapy, targeted therapy, and more recently also immunotherapy has demonstrated to significantly improve their survival outcomes. However, this gain is often obtained at the cost of higher toxicity calling for the need of increased attention toward survivorship-related issues, including fertility preservation in young women. According to available guidelines, health care providers should offer oncofertility counseling to all patients with cancer diagnosed at reproductive age. Counselling should focus on the risk of gonadotoxicity of anticancer treatments and on the access to fertility preservation techniques. However, several surveys have demonstrated suboptimal implementation of these recommendations. This review aims at summarizing the available evidence on oncofertility to guide health care providers involved in the management of young women with breast cancer. Available and effective options for fertility preservation include oocyte/embryo cryopreservation or ovarian tissue cryopreservation. Patient, disease, and treatment characteristics should be carefully considered when offering these strategies. Ovarian function preservation with gonadotrophin-releasing hormone agonists during chemotherapy should be discussed and offered to every premenopausal woman concerned about developing premature ovarian insufficiency and independently of her wish to preserve fertility. Current available data confirm that pregnancy occurring after proper treatment for breast cancer is safe, both in terms of long-term clinical outcomes and for the babies. Fertility preservation and pregnancy desire should be pivotal components of the multimodal management of breast cancer in young women, and require a multidisciplinary approach based on close collaborations between oncologists and fertility specialists.

Controlled ovarian hyperstimulation parameters are not associated with de novo chromosomal abnormality rates and clinical pregnancy outcomes in preimplantation genetic testing

OBJECTIVE

This study aimed to determine whether controlled ovarian hyperstimulation (COH) parameters influence the incidence of de novo chromosomal abnormalities (> 4 Mb) in blastocysts and, thus, clinical pregnancy outcomes in preimplantation genetic testing (PGT).

METHODS

Couples who underwent preimplantation genetic testing for structural chromosome rearrangements (PGT-SR) and monogenic disorders (PGT-M) were included in this study. The relationships of maternal age, paternal age, stimulation protocol, exogenous gonadotropin dosage, duration of stimulation, number of oocytes retrieved and estradiol (E₂) levels on human chorionic gonadotropin (hCG) trigger day with the incidence of de novo chromosomal abnormalities were assessed. Blastocysts were biopsied, and nuclear DNA was sequenced using next-generation sequencing (NGS). Clinical pregnancy outcomes after single euploid blastocyst transfers under different COH parameters were assessed.

RESULTS

A total of 1,710 and 190 blastocysts were biopsied for PGT-SR and PGT-M, respectively. The rate of de novo chromosomal abnormalities was found to increase with maternal age (p< 0.001) and paternal age (p = 0.019) in the PGT-SR group. No significant differences in the incidence of de novo chromosomal abnormalities were seen for different maternal or paternal age groups between the PGT-SR and PGT-M groups (p > 0.05). Stratification analysis by gonadotropin dosage, stimulation protocol, duration of stimulation, number of retrieved oocytes and E₂ levels on hCG trigger day revealed that de novo chromosomal abnormalities and clinical pregnancy outcomes were not correlated with COH parameters after adjusting for various confounding factors.

CONCLUSION

The rate of de novo chromosomal abnormalities was found to increase with maternal or paternal age. COH parameters were found to not influence the incidence of de novo chromosomal abnormalities or clinical pregnancy outcomes.

Circulating Tumor DNA to Interrogate the Safety of Letrozole-Associated Controlled Ovarian Stimulation for Fertility Preservation in Breast Cancer Patients

Background

Current fertility preservation strategies for young breast cancer patients planning a future motherhood include the association of controlled ovarian stimulation with the aromatase inhibitor letrozole (let-COS) to harvest mature oocytes while maintaining low estradiol levels. Despite this is a widely adopted protocol, the safety of let-COS on breast cancer outcomes has been poorly investigated and its use remains off-label. We assessed the safety of let-COS in breast cancer patients using circulating tumor DNA (ctDNA) as a surrogate biomarker of disease recurrence.

Methods

BROVALE is an interventional non-randomized prospective study designed to evaluate the efficacy and safety of let-COS for fertility preservation in early breast cancer patients before starting (neo)adjuvant chemotherapy. Letrozole was administered throughout the COS cycle, until ovulation triggering. Safety was a secondary endpoint. Data on oncological outcomes were collected during the follow-up as well as plasma and whole blood for evaluation of ctDNA levels at the time of enrollment (i.e. before starting let-COS) and oocyte retrieval (i.e. 48 hours after the last administration of letrozole). Targeted gene sequencing on the primary tumor samples was performed to identify specific mutations used for ctDNA analysis by digital PCR. DNA extracted from whole blood samples was used to discriminate between somatic and germline mutations.

Results

From April 2014 to May 2017, 29 young early breast cancer patients enrolled in the BROVALE study who had available tissue samples participated to the ctDNA substudy. Among them, 15 had at least one validated somatic mutation. ctDNA was undetectable neither before nor after let-COS in 9 of them. Six patients had detectable ctDNA in the plasma samples collected before Let-COS. No change in ctDNA level after let-COS was observed in 3 patients and the level decreased (fold-change ≤ 0.5) in two women. One patient experienced an increased (fold-change ≥ 2) in ctDNA level but without disease relapse 34 months after diagnosis.

Conclusions

No increase in ctDNA level was observed in 93% (14/15) of the patients receiving let-COS supporting its use as a safe strategy for young women with early breast cancer interested in fertility preservation before chemotherapy.

Efficacy and Safety of Controlled Ovarian Stimulation With or Without Letrozole Co-administration for Fertility Preservation: A Systematic Review and Meta-Analysis

Background: The co-administration of letrozole during controlled ovarian stimulation (COS) with gonadotropins is used to limit the potentially harmful effects of a supra-physiological rise in estrogen levels on hormone-sensitive cancers. However, the efficacy and safety of adding letrozole to COS remain debated.

Methods: This is a systematic review and meta-analysis of published studies that compared the efficacy and safety of COS with co-administration of letrozole vs. COS without letrozole in all patient populations. A secondary analysis was done including only the studies in breast cancer patients. The primary efficacy endpoint was the number of retrieved mature Metaphase II (MII) oocytes. Secondary efficacy and safety endpoints were total number of oocytes, maturation rate, fertilization rate, number of cryopreserved embryos, peak estradiol levels, progesterone levels, and total gonadotropin dose. Data for each endpoint were reported and analyzed thorough mean ratio (MR) with 95% confidence interval (CI).

Results: A total of 11 records were selected including 2,121 patients (990 patients underwent COS with letrozole and 1,131 COS without letrozole). The addition of letrozole to COS did not have any negative effect on the number of mature oocytes collected (MR = 1.00, 95% CI = 0.87–1.16; P = 0.967) and the other efficacy endpoints. COS with letrozole was associated with significantly decreased peak estradiol levels (MR = 0.28, 95% CI = 0.24–0.32; P < 0.001). Similar results were observed in the secondary analysis including only breast cancer patients.

Conclusions: These findings are reassuring on the efficacy and safety of COS with gonadotropins and letrozole and are particularly important for fertility preservation in women with hormone-sensitive cancers.

Gender-specific aspects related to type of fertility preservation strategies and access to fertility care

Survivorship is an area of paramount importance to be addressed as early as possible after cancer diagnosis by all health care providers. On this regard, cancer care in young patients often poses several age-related considerations among which fertility and pregnancy-related issues have a crucial role. According to the available guidelines on the topic, all patients with cancer diagnosed during their reproductive years should be provided a proper oncofertility counselling before starting anticancer treatments. This is an important step in order to inform patients about the potential treatment-induced gonadotoxicity and the available strategies for fertility preservation so that they can be referred as early as possible to fertility specialists if potentially interested in these options.In this manuscript, we aim to provide an up to date overview on the available efficacy and safety data with the main strategies for fertility preservation in male and female cancer patients in order to help optimising the oncofertility counselling performed by healthcare providers involved in cancer care and dealing with young patients. In male patients with cancer, sperm cryopreservation is the standard technique for fertility preservation. Oocyte/embryo cryopreservation, ovarian tissue cryopreservation and temporary ovarian suppression with luteinising hormone-releasing hormone agonists during chemotherapy are the main options in female patients with cancer.A multidisciplinary management building a strong network between fertility and oncology/haematology units is crucial to properly address fertility care in all young patients with cancer, at both diagnosis and during oncologic follow-up. Discussing fertility and pregnancy-related issues with young patients with cancer has to be considered mandatory nowadays keeping in mind that returning to a normal life (including the possibility to have a family and to live with as few side effects as possible) should be considered an important ambition in cancer care in the 21st century .

The PREgnancy and FERtility (PREFER) study: an Italian multicenter prospective cohort study on fertility preservation and pregnancy issues in young breast cancer patients

Background

Fertility and pregnancy issues are of key importance for young breast cancer patients. Despite several advances in the field, there are still multiple unmet needs and barriers in discussing and dealing with these concerns. To address the significant challenges related to fertility and pregnancy issues, the PREgnancy and FERtility (PREFER) study was developed as a national comprehensive program aiming to optimize care and improve knowledge around these topics.

Methods

The PREFER study is a prospective cohort study conducted across several Italian institution affiliated with the Gruppo Italiano Mammella (GIM) group evaluating patterns of care and clinical outcomes of young breast cancer patients dealing with fertility and pregnancy issues. It is composed of two distinctive studies: PREFER-FERTILITY and PREFER-PREGNANCY. The PREFER-FERTILITY study is enrolling premenopausal patients aged 18–45 years, diagnosed with non-metastatic breast cancer, who are candidates to (neo)adjuvant chemotherapy and not previously exposed to anticancer therapies. The primary objective is to obtain and centralize data about patients’ preferences and choices towards the available fertility preserving procedures. The success and safety of these strategies and the hormonal changes during chemotherapy and study follow-up are secondary objectives. The PREFER-PREGNANCY study is enrolling survivors achieving a pregnancy after prior history of breast cancer and patients diagnosed with pregnancy-associated breast cancer (PABC). The primary objectives are to obtain and centralize data about the management and clinical outcomes of these women. Patients’ survival outcomes, and the fetal, obstetrical and paediatric care of their children are secondary objectives. For both studies, the initial planned recruitment period is 5 years and patients will remain in active follow-up for up to 15 years. The PREFER-FERTILITY study was first activated in November 2012, and the PREFER-PREGNANCY study in May 2013.

Discussion

The PREFER study is expected to support and improve oncofertility counseling in Italy, to explore the real need of fertility preserving procedures, and to acquire prospectively more robust data on the efficacy and safety of the available strategies for fertility preservation, on the management of breast cancer survivors achieving a pregnancy and of women with PABC (including the possible short- and long-term complications in their children).

Trial registration number

ClinicalTrials.gov identifier: NCT02895165 (Retrospectively registered in August 2016).