Assessment of Ovarian Function in Phase III (Neo)Adjuvant Breast Cancer Clinical Trials: A Systematic Evaluation

PARP inhibitors during conception and pregnancy in breast cancer

Approximately 1 in 10 women diagnosed with breast cancer before the age of 35 carry germline BRCA pathogenic/likely pathogenic variants. Poly (ADP-ribose) polymerase (PARP) inhibitors have been recently approved in the treatment of both early and advanced breast cancer. However, there are no published cases of exposure to PARP inhibitors during pregnancy. Treatment with PARP inhibitors during pregnancy is currently contraindicated and can potentially harm fertility in young women with breast cancer. We here summarize all clinical and preclinical data on the effect of PARP inhibitors on pregnancy, fertility and breast-feeding to provide guidance on their optimal use in women of childbearing potential.

Balancing Fertility Preservation and Treatment Efficacy in (Neo)adjuvant Therapy for Adolescent and Young Adult Breast Cancer Patients: a Narrative Review

PURPOSE OF REVIEW

Adolescent and young adult (AYA) breast cancer survivors face a significant risk of infertility due to the gonadotoxic effects of (neo)adjuvant therapy, which complicates their ability to conceive post-treatment. While (neo)adjuvant therapy primarily aims to improve recurrence-free and overall survival, fertility preservation strategies should also be considered for young patients. This narrative review explores recent advancements in fertility preservation techniques, such as oocyte, embryo, and ovarian tissue cryopreservation, and evaluates the feasibility of modifying breast cancer (neo)adjuvant therapy to preserve fertility without compromising survival outcomes.

RECENT FINDINGS

Our review highlights that clinical trials with co-primary endpoints of oncological safety and fertility preservation are limited, and substituting standard treatment regimens solely for fertility preservation is currently not recommended. Nevertheless, new clinical studies have emerged that either exclude highly ovarian-toxic agents, such as cyclophosphamide, or omit adjuvant therapy altogether, even if fertility preservation is not their primary endpoint. Unfortunately, many of these trials have not evaluated ovarian toxicity. Notably, since 2020, major oncology organizations, including the American Society of Clinical Oncology (ASCO), the European Society of Medical Oncology (ESMO) have advocated for the routine assessment of ovarian toxicity in all clinical trials. The review underscores the importance of incorporating ovarian toxicity as a standard endpoint in future trials involving premenopausal breast cancer patients to identify treatment regimens that can effectively balance fertility preservation with treatment efficacy.

Clinical significance of serum estradiol monitoring in women receiving adjuvant aromatase inhibitor for hormone receptor-positive early breast cancer

PURPOSE

The limited understanding of long-term estradiol (E2) suppression poses challenges to the effectiveness of adjuvant therapy with aromatase inhibitors (AI), necessitating comprehensive serum E2 monitoring to address this issue. Therefore, our objective was to investigate serum E2 levels in women undergoing adjuvant AI treatment and evaluate the significance of such monitoring.

PATIENTS AND METHODS

In this prospective cohort study, we recruited women who had received adjuvant AI treatment, including those who underwent ovarian function suppression (OFS). Serum E2 levels were measured using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The primary endpoint was the proportion of women with E2 levels exceeding 2.72 pg/mL, indicating inadequate suppression achieved with AI therapy.

RESULTS

A total of 706 patients were enrolled, including 482 women with OFS in combination with AI. Among them, 116 women (16.4 %) exhibited E2 levels exceeding 2.72 pg/mL. The majority of serum E2 elevations (77.6 %) occurred within the first two years of initiating endocrine therapy. Younger age, no prior chemotherapy, shorter duration of the current treatment regimen, and lower follicle stimulating hormone (FSH) levels were associated with inadequate E2 suppression. Serum E2 concentrations demonstrated dynamic variations and occasional rebound following adjuvant AI therapy.

CONCLUSIONS

Despite receiving adjuvant AI treatment for nearly two years, a certain proportion of patients failed to achieve the adequate threshold of E2 suppression. Our findings emphasize the significance of monitoring serum E2 levels during adjuvant AI therapy, particularly within the first two years. Further research is imperative to facilitate a more comprehensive comprehension of E2 monitoring.

Onset and resolution of ovarian toxicity with nirogacestat treatment in females with desmoid tumors: Updated safety analyses from the DeFi phase 3 study

INTRODUCTION

Nirogacestat is a targeted gamma secretase inhibitor approved in the United States for adults with progressing desmoid tumors. In the phase 3 DeFi study (NCT03785964) of nirogacestat, ovarian toxicity (OT) was identified as a safety signal among females of reproductive potential (FORP). This analysis further describes the incidence, presentation, and resolution of OT.

METHODS

Patients were randomized to twice-daily oral nirogacestat (150 mg) or placebo, taken in continuous 28-day cycles. Investigator-identified OT in FORP was based on abnormal reproductive hormone values or perimenopausal symptoms (or both). Adverse event follow-up was conducted to assess OT resolution. Post hoc analyses included return of menstruation and return of follicle-stimulating hormone (FSH) to within normal limits (WNL) (≤20.4 mIU/mL).

RESULTS

Of 92 randomized females, 73 in the safety population were FORP (n = 36 nirogacestat, n = 37 placebo). OT was identified in 75% (27 of 36) receiving nirogacestat and 0% (0 of 37) receiving placebo. As of October 24, 2022, investigators reported OT resolution in 78% (21 of 27) of patients, with median OT duration of 19.1 weeks. Off-treatment resolution was reported in all 11 patients (100%) who stopped nirogacestat treatment; of these, all nine with available menstruation information experienced return of menstruation and eight had FSH WNL at last reported assessment. Resolution was reported in 10 of 14 (71%) while on nirogacestat; of these, all 10 experienced return of menstruation and seven had FSH WNL. Two patients were lost to follow-up.

CONCLUSION

Most FORP treated with nirogacestat experienced OT, with the majority resolving, including all who stopped treatment, suggesting that OT is transient.

Assessing risks and knowledge gaps on the impact of systemic therapies in early breast cancer on female fertility: A systematic review of the literature

The therapeutic landscape for early breast cancer (eBC) has expanded by introducing novel anticancer agents into clinical practice. During their reproductive years, women with eBC should be informed of the potential risk of premature ovarian insufficiency (POI) and infertility with the proposed systemic therapy. Although the topic of female fertility is becoming increasingly relevant in patients with cancer, limited information is available on the gonadotoxicity of new agents available for eBC treatment. Analyses from clinical trials and prospective data on ovarian function biomarkers are lacking. The purpose of this systematic review is to report the available preclinical and clinical data on female fertility risk with the use of the new agents that are part of clinical practice use or under development for eBC management. This review highlights the clear need to perform additional research efforts to improve our understanding on the gonoadtoxicity of new anticancer agents.

Palbociclib combined with endocrine treatment in hormone receptor-positive, HER2-negative breast cancer patients with high relapse risk after neoadjuvant chemotherapy: subgroup analyses of premenopausal patients in PENELOPE-B

BACKGROUND

The PENELOPE-B study demonstrated that the addition of 1-year post-neoadjuvant palbociclib to endocrine therapy (ET) in patients with high-risk early breast cancer (BC) did not improve invasive disease-free survival (iDFS) compared to placebo. Here, we report results for premenopausal women.

PATIENTS AND METHODS

Patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative BC at high risk of relapse [defined as no pathological complete response after neoadjuvant chemotherapy and a clinical, pathological stage, estrogen receptor, grading (CPS-EG) score ≥3 or 2/ypN+] were randomized to receive 13 cycles of palbociclib or placebo + standard ET. Ovarian function (OF) was evaluated by centrally assessed estradiol, follicle-stimulating hormone and anti-Müllerian hormone serum levels.

RESULTS

Overall, 616 of 1250 randomized patients were premenopausal; of these, 30.0% were <40 years of age, 47.4% had four or more metastatic lymph nodes, and 58.2% had a CPS-EG score ≥3. 66.1% of patients were treated with tamoxifen alone, and 32.9% received ovarian function suppression (OFS) in addition to either tamoxifen or aromatase inhibitor (AI). After a median follow-up of 42.8 months (97.2% completeness) no difference in iDFS between palbociclib and placebo was observed [hazard ratio = 0.95, 95% confidence interval (CI) 0.69-1.30, P = 0.737]. The estimated 3-year iDFS rate was marginally higher in the palbociclib arm (80.6% versus 78.3%). Three year iDFS was higher in patients receiving AI than tamoxifen plus OFS or tamoxifen alone (86.0% versus 78.6% versus 78.0%). Patients receiving tamoxifen plus OFS showed a favorable iDFS with palbociclib (83.0% versus 74.1%, hazard ratio = 0.52, 95% CI 0.27-1.02, P = 0.057). Hematologic adverse events were more frequent with palbociclib (76.1% versus 1.9% grade 3-4, P < 0.001). Palbociclib seems not to negatively impact the OF throughout the treatment period.

CONCLUSIONS

In premenopausal women, who received tamoxifen plus OFS as ET, the addition of palbociclib to ET results in a favorable iDFS. The safety profile seems favorable and in contrast to chemotherapy palbociclib does not impact OF throughout the treatment period.

Fertility and Sexual Health in Young Women with Early-Stage Breast Cancer

Fertility and sexual health may be impaired by early breast cancer treatment in young women, and these issues should be addressed at diagnosis and through survivorship. Future fertility interest and risk should be considered and communicated, and early referral made to an infertility specialist for those interested. Data regarding safety of fertility preservation options as well as pregnancy after breast cancer are overall reassuring. Patients should be counseled about the impact of systemic therapies and breast surgeries on sexual health outcomes and educated about and referred as needed for available strategies for prevention and management of impairment.

Measuring ovarian toxicity in clinical trials: an American Society of Clinical Oncology research statement

Anticancer agents can impair ovarian function, resulting in premature menopause and associated long-term health effects. Ovarian toxicity is not usually adequately assessed in trials of anticancer agents, leaving an important information gap for patients facing therapy choices. This American Society of Clinical Oncology (ASCO) statement provides information about the incorporation of ovarian toxicity measures in trial design. ASCO recommends: (1) measurement of ovarian toxicity in relevant clinical trials of anticancer agents that enrol post-pubertal, pre-menopausal patients; (2) collection of ovarian function measures at baseline and at 12-24 months after anticancer agent cessation, as a minimum, and later in line with the trial schedule; and (3) assessment of both clinical measures and biomarkers of ovarian function. ASCO recognises that routine measurement of ovarian toxicity and function in cancer clinical trials will add additional complexity and burden to trial resources but asserts that this issue is of such importance to patients that it cannot continue to be overlooked.

Making a good egg: human oocyte health, aging, and in vitro development

Mammalian eggs (oocytes) are formed during fetal life and establish associations with somatic cells to form primordial follicles that create a store of germ cells (the primordial pool). The size of this pool is influenced by key events during the formation of germ cells and by factors that influence the subsequent activation of follicle growth. These regulatory pathways must ensure that the reserve of oocytes within primordial follicles in humans lasts for up to 50 years, yet only approximately 0.1% will ever be ovulated with the rest undergoing degeneration. This review outlines the mechanisms and regulatory pathways that govern the processes of oocyte and follicle formation and later growth, within the ovarian stroma, through to ovulation with particular reference to human oocytes/follicles. In addition, the effects of aging on female reproductive capacity through changes in oocyte number and quality are emphasized, with both the cellular mechanisms and clinical implications discussed. Finally, the details of current developments in culture systems that support all stages of follicle growth to generate mature oocytes in vitro and emerging prospects for making new oocytes from stem cells are outlined.

The future of fertility preservation for women treated with chemotherapy

Cytotoxic chemotherapies have been a mainstay of cancer treatment, but are associated with numerous systemic adverse effects, including impacts to fertility and endocrine health. Irreversible ovarian damage and follicle depletion are side-effects of chemotherapy that can lead to infertility and premature menopause, both being major concerns of young cancer patients. Notably, many women will proceed with fertility preservation, but unfortunately existing strategies don't entirely solve the problem. Most significantly, oocyte and embryo freezing do not prevent cancer treatment-induced ovarian damage from occurring, which may result in the impairment of long-term hormone production. Unfortunately, loss of endogenous endocrine function is not fully restored by hormone replacement therapy. Additionally, while GnRH agonists are standard care for patients receiving alkylating chemotherapy to lessen the risk of premature menopause, their efficacy is incomplete. The lack of more broadly effective options stems, in part, from our poor understanding of how different treatments damage the ovary. Here, we summarise the impacts of two commonly utilised chemotherapies - cyclophosphamide and cisplatin - on ovarian function and fertility, and discuss the mechanisms underpinning this damage. Additionally, we critically analyse current research avenues in the development of novel fertility preservation strategies, with a focus on fertoprotective agents.

Poly-ADP-ribose polymerase (PARP) inhibitors and ovarian function

Poly-ADP-ribose polymerase (PARP) plays an important role in DNA damage detection and repair. PARP inhibitors (PARPi) are a novel class of targeted agents used widely in the treatment of female cancer patients with BRCA mutations, including younger patients. However, the impact of PARPi on ovarian function remains a considerable problem in clinical practice. In this review article, we summarize the current understanding of PARPi's effects on the function of ovary and discuss their potential underlying mechanisms, highlighting the significance of further investigation on the criterion for ovarian failure and its preventive approaches during PARPi treatment.

Selection of endpoints in breast cancer clinical trials: a qualitative study of key trial stakeholders

Clinical trial endpoints are fundamental for evaluating the safety and efficacy of cancer therapies, yet it is not well understood how they are selected or the role of stakeholder groups in deciding endpoints. This study aimed to explore how clinical trial endpoints are selected in breast cancer trials of anti-cancer drugs through semi structured interviews with purposively selected stakeholders involved in breast cancer clinical trials (clinicians, consumers, pharmaceutical company representatives, and members of drug regulatory agencies). Participants were asked to describe the process of selecting trial endpoints. Interviews were transcribed verbatim and analysed using inductive thematic analysis supported by NVivo software. Saturation of the main themes was reached and the final sample included 25 participants from 14 countries (9 clinicians, 7 consumers, 5 members of regulatory agencies, 4 pharmaceutical company representatives). Pharmaceutical companies were almost always identified as the main decision maker. While most consumers and pharmaceutical company representatives felt clinicians and consumers influenced trial design, some clinicians and regulators reported consumers and clinicians had little influence. Factors identified as important considerations in determining trial endpoints included the main goal of the trial, established standardised endpoints, resources, and the investigational agent studied. All pharmaceutical advisors reported that meeting the requirements for regulatory approval was the major factor considered. Clinical trial endpoint selection is largely decided by the pharmaceutical industry, driven by requirements for regulatory approval. Given the limited influence from clinicians and consumers, guidance by regulatory agencies will be important for future inclusion of novel endpoints in clinical trials.

Understanding the barriers to, and facilitators of, ovarian toxicity assessment in breast cancer clinical trials

BACKGROUND

Detailed toxicity data are routinely collected in breast cancer (BC) clinical trials. However, ovarian toxicity is infrequently assessed, despite the adverse impacts on fertility and long-term health from treatment-induced ovarian insufficiency.

OBJECTIVES

To determine the barriers to and facilitators of ovarian toxicity assessment in BC trials of anti-cancer drugs.

METHODS

Semi-structured interviews were conducted with purposively selected stakeholders from multiple countries involved in BC clinical trials (clinicians, consumers, pharmaceutical company representatives, members of drug-regulatory agencies). Participants were asked to describe the perceived benefits and barriers to evaluating ovarian toxicity. Interviews were transcribed verbatim, coded in NVivo software and analysed using inductive thematic analysis.

RESULTS

Saturation of the main themes was reached and the final sample size included 25 participants from 14 countries (9 clinicians, 7 consumers, 5 members of regulatory agencies, 4 pharmaceutical company representatives); half were female. The main reported barrier to ovarian toxicity assessment was that the issue was rarely considered. Reasons included that these data are less important than survival data and are not required for regulatory approval. Overall, most participants believed evaluating the impact of BC treatments on ovarian function is valuable. Suggested strategies to increase ovarian toxicity assessment were to include it in clinical trial design guidelines and stakeholder advocacy.

CONCLUSION

Lack of consideration about measuring ovarian toxicity in BC clinical trials that include premenopausal women suggest that guidelines and stronger advocacy from stakeholders, including regulators, would facilitate its more frequent inclusion in future trials, allowing women to make better informed treatment decisions.

Checkpoint inhibitor immunotherapy diminishes oocyte number and quality in mice

Loss of fertility is a major concern for female reproductive-age cancer survivors, since a common side-effect of conventional cytotoxic cancer therapies is permanent damage to the ovary. While immunotherapies are increasingly becoming a standard of care for many cancers-including in the curative setting-their impacts on ovarian function and fertility are unknown. We evaluated the effect of immune checkpoint inhibitors blocking programmed cell death protein ligand 1 and cytotoxic T lymphocyte-associated antigen 4 on the ovary using tumor-bearing and tumor-free mouse models. We find that immune checkpoint inhibition increases immune cell infiltration and tumor necrosis factor-α expression within the ovary, diminishes the ovarian follicular reserve and impairs the ability of oocytes to mature and ovulate. These data demonstrate that immune checkpoint inhibitors have the potential to impair both immediate and future fertility, and studies in women should be prioritized. Additionally, fertility preservation should be strongly considered for women receiving these immunotherapies, and preventative strategies should be investigated in future studies.

Potential ovarian toxicity and infertility risk following targeted anti-cancer therapies

Unlike traditional chemotherapy agents which are generally cytotoxic to all cells, targeted anti-cancer therapies are designed to specifically target proliferation mechanisms in cancer cells but spare normal cells, resulting in high potency and reduced toxicity. There has therefore been a rapid increase in their development and use in clinical settings, including in curative-intent treatment regimens. However, the targets of some of these drugs including kinases, epigenetic regulatory proteins, DNA damage repair enzymes and proteasomes, have fundamental roles in governing normal ovarian physiology. Inhibiting their action could have significant consequences for ovarian function, with potentially long-lasting adverse effects which persist after cessation of treatment, but there is limited evidence of their effects on reproductive function. In this review, we will use literature that examines these pathways to infer the potential toxicity of targeted anti-cancer drugs on the ovary.

Lay summary

Compared to traditional chemotherapy agents, anti-cancer therapies are thought to be highly effective at targeting cancer cells but sparing normal cells, resulting in reduced drug side effects. However, many of processes within the cells that these drugs affect are also important for the ovary to work normally, so suppressing them in this way could have long-lasting implications for female fertility. This review examines the potential toxicity of anti-cancer therapies on the ovary.

Impact of age on clinical outcomes and efficacy of adjuvant dual anti-HER2 targeted therapy

Background

Young age at breast cancer (BC) diagnosis has historically been a rationale for overtreatment. Limited data with short follow-up exist on the prognostic value of age at diagnosis in HER2-positive BC and the benefit of anti-HER2 therapy in young patients.

Methods

APHINITY (NCT01358877) is an international, placebo-controlled, double-blind randomized phase III trial in HER2-positive early BC patients investigating the addition of pertuzumab to adjuvant chemotherapy plus trastuzumab. The prognostic and predictive value of age on invasive disease-free survival (IDFS) as continuous and dichotomous variable (aged 40 years or younger and older than 40 years) was assessed. A subpopulation treatment effect pattern plot analysis was conducted to illustrate possible treatment-effect heterogeneity based on age as a continuous factor.

Results

Of 4804 included patients, 768 (16.0%) were aged 40 years or younger at enrollment. Median follow-up was 74 (interquartile range = 62-75) months. Young age was not prognostic either as dichotomous (hazard ratio [HR] = 1.06, 95% confidence interval [CI] = 0.84 to 1.33) or continuous (HR = 1.00, 95% CI = 1.00 to 1.01) variable. Lack of prognostic effect of age was observed irrespective of hormone receptor status and treatment arm. No statistically significant interaction was observed between age and pertuzumab effect (P_interaction = 0.61). Adding pertuzumab improved IDFS for patients in the young (HR = 0.86, 95% CI = 0.56 to 1.32) and older (HR = 0.75, 95% CI = 0.62 to 0.92) cohorts. Similar results were observed irrespective of hormone receptor status. Subpopulation treatment effect pattern plot analysis confirmed the benefit of pertuzumab in 6-year IDFS across age subpopulations.

Conclusions

In patients with HER2-positive early BC treated with modern anticancer therapies, young age did not demonstrate either prognostic or predictive value, irrespective of hormone receptor status.

Heavy metal and metalloid - induced reproductive toxicity

Heavy metals and metalloid exposure are among the most common factors responsible for reproductive toxicity in human beings. Several studies have indicated that numerous metals and metalloids can display severe adverse properties on the human reproductive system. Metals like lead, silver, cadmium, uranium, vanadium, and mercury and metalloids like arsenic have been known to induce reproductive toxicity. Moderate to minute quantities of lead may affect several reproductive parameters and even affect semen quality. The ecological and industrial exposures to the various heavy metals and metalloids have disastrous effects on the reproductive system ensuing in infertility. This work emphasizes the mechanism and pathophysiology of the aforementioned heavy metals and metalloids in reproductive toxicity. Additionally, this work aims to cover the classical protective mechanisms of zinc, melatonin, chelation therapy, and other trending methods to prevent heavy metal-induced reproductive toxicity.