Role of Ovarian Function Suppression in Premenopausal Women with Early Breast Cancer

Epigenetic Dysregulation and Its Correlation with the Steroidogenic Machinery Impacting Breast Pathogenesis: Data Mining and Molecular Insights into Therapeutics

Breast cancer (BC) is a heterogeneous condition and comprises molecularly distinct subtypes. An imbalance in the levels of epigenetic histone deacetylases (HDACs), modulating estrogen accumulation, especially 17β-estradiol (E2), promotes breast tumorigenesis. In the present study, analyses of The Cancer Genome Atlas (TCGA) pan-cancer normalized RNA-Seq datasets revealed the dysregulation of 16 epigenetic enzymes (among a total of 18 members) in luminal BC subtypes, in comparison to their non-cancerous counterparts. Explicitly, genomic profiling of these epigenetic enzymes displayed increases in HDAC1, 2, 8, 10, 11, and Sirtuins (SIRTs) 6 and 7, and decreases in HDAC4-7, -9, and SIRT1-4 levels, respectively, in TCGA breast tumors. Kaplan-Meier plot analyses showed that these HDACs, with the exception of HDAC2 and SIRT2, were not correlated with the overall survival of BC patients. Additionally, disruption of the epigenetic signaling in TCGA BC subtypes, as assessed using both heatmaps and boxplots, was associated with the genomic expression of factors that are instrumental for cholesterol trafficking/utilization for accelerating estrogen/E2 levels, in which steroidogenic acute regulatory protein (STAR) mediates the rate-limiting step in steroid biosynthesis. TCGA breast samples showed diverse expression patterns of a variety of key steroidogenic markers and hormone receptors, including LIPE, CYP27A1, STAR, STARD3, CYP11A1, CYP19A1, ER, PGR, and ERBB2. Moreover, regulation of STAR-governed steroidogenic machinery was found to be influenced by various transcription factors, i.e., CREB1, CREM, SF1, NR4A1, CEBPB, SREBF1, SREBF2, SP1, FOS, JUN, NR0B1, and YY1. Along these lines, ingenuity pathway analysis (IPA) recognized a number of new targets and downstream effectors influencing BCs. Of note, genomic, epigenomic, transcriptional, and hormonal anomalies observed in human primary breast tumors were qualitatively similar in pertinent BC cell lines. These findings identify the functional correlation between dysregulated epigenetic enzymes and estrogen/E2 accumulation in human breast tumors, providing the molecular insights into more targeted therapeutic approaches involving the inhibition of HDACs for combating this life-threatening disease.

The crosstalk between ubiquitination and endocrine therapy

Endocrine therapy (ET), also known as hormone therapy, refers to the treatment of tumors by regulating and changing the endocrine environment and hormone levels. Its related mechanism is mainly through reducing hormone levels and blocking the binding of hormones to corresponding receptors, thus blocking the signal transduction pathway to stimulate tumor growth. However, with the application of ET, some patients show resistance to ET, which is attributed to abnormal accumulation of hormone receptors (HRs) and the production of multiple mutants of HRs. The targeted degradation of abnormal accumulation protein mediated by ubiquitination is an important approach that regulates the protein level and function of intracellular proteins in eukaryotes. Here, we provide a brief description of the traditional and novel drugs available for ET in this review. Then, we introduce the link between ubiquitination and ET. In the end, we elaborate the clinical application of ET combined with ubiquitination-related molecules. KEY MESSAGES: • A brief description of the traditional and novel drugs available for endocrine therapy (ET). • The link between ubiquitination and ET. • The clinical application of ET combined with ubiquitination-related molecules.

Ovarian Function Suppression: A Deeper Consideration of the Role in Early Breast Cancer and its Potential Impact on Patient Outcomes: A Consensus Statement from an International Expert Panel

It has been suggested that the benefit of adjuvant chemotherapy (CT) in premenopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) early breast cancer may be related, at least in part, to CT-induced ovarian function suppression (OFS) in this subgroup of patients. Although this hypothesis has not been directly tested in large randomized clinical trials, the observations from prospective studies have been remarkably consistent in showing a late benefit of CT among the subgroup of patients who benefit (ie, women who were close to menopause). The hypothesis has important clinical implications, as it may be possible to spare the associated adverse effects of adjuvant CT in a select group of women with early breast cancer, in favor of optimizing OFS and endocrine therapy (ET), without compromising clinical outcomes. Such an approach has the added benefit of preserving the key quality of life outcomes in premenopausal women, particularly by preventing the irreversible loss of ovarian function that may result from CT use. For this reason, we convened an international panel of clinical experts in breast cancer treatment to discuss the key aspects of the available data in this area, as well as the potential clinical implications for patients. This article summarizes the results of these discussions and presents the consensus opinion of the panel regarding optimizing the use of OFS for premenopausal women with HR+, HER2- early breast cancer.

Effectiveness of a 6-Month 22.5-mg Leuprolide Acetate Depot Formulation With Tamoxifen for Postoperative Premenopausal Estrogen Suppression in Hormone Receptor-Positive Breast Cancer

Background

In patients with hormone receptor-positive (HR+)/premenopausal breast cancer, luteinizing hormone-releasing hormone analogs (LHRHas) are used as standard endocrine treatment. Based on previous clinical studies, 1-month formulations are recommended in most breast cancer treatment guidelines, but long-acting formulations facilitate reductions in side effects and patient discomfort caused by frequent administration. However, few efficacy studies have been conducted on 6-month formulations. Therefore, this study aimed to evaluate the efficacy of 6-month formulations of LHRHas.

Methods

This retrospective study was conducted from January 2018 to December 2019 and involved premenopausal patients with HR+ breast cancer administered 6-month LHRHas as adjuvant treatment after surgery, and those previously administered chemotherapy or other LHRHa types were excluded. Patients’ estradiol (E2) and follicle-stimulating hormone (FSH) levels were measured before surgery, and their E2 levels were also measured at 3, 6, 12, 18, and 24 months at periodic postsurgical examinations.

Results

A total of 228 patients were included, and the median patient age was 44 (range, 25–54) years. The mean serum E2 and FSH levels before surgery were 69.7 (range, 4–683) pg/mL and 7.3 (range, 0.4–88.9) mIU/mL, respectively, whereas the mean serum E2 level monitored at intervals during the 6-month LHRHa administration was 5.5 (range, 4.0–52) pg/mL. No women menstruated during the follow-up period after the LHRHas administration, and the E2 levels were less than 30 pg/mL in all patients except one.

Conclusions

The 6-month LHRHa formulation adequately suppressed ovarian function in premenopausal patients with HR+ breast cancer. This indicates that long-acting LHRHas can be effectively used for patient convenience and that there is high compliance with long-term use.

Change in Estradiol Levels among Premenopausal Patients with Breast Cancer Treated Using Leuprolide Acetate 11.25 Milligrams 3-Month Depot and Tamoxifen

The combination of luteinizing hormone-releasing hormone analogs (LHRHa) with tamoxifen is used as a standard postoperative adjuvant therapy in patients with hormone receptor-positive/premenopausal breast cancer. Long-acting LHRHa formulations offer advantages in terms of patient convenience. However, data on the effectiveness of the 3-month (3M) acting formulation are still insufficient. This study was performed on patients who received the 3M LHRHa after surgery. The serum estradiol (E2) and follicle-stimulating hormone levels were measured before surgery, and periodically after surgery. In total, 318 patients were included in the study and analyzed. The mean E2 level before surgery was 63.7 pg/mL, while the mean E2 level during the administration of 3M LHRHa was 4.9 pg/mL. None of the patients were menstruating and had E2 values above 30.0 pg/mL. It is thought that the 3M LHRHa formulation can suppress the ovarian function effectively and be safely used to improve compliance.

Cost analysis of leuprorelin acetate in Japanese pre-menopausal breast-cancer patients: comparison between 6-month and 3-month depot formulations

AIMS

The aim in this study is to evaluate economic value for leuprorelin acetate 6-month depot compared with leuprorelin acetate 3-month depot in Japanese pre-menopausal breast cancer patients from a societal perspective.

METHODS

The cost analysis was conducted by estimating direct and indirect cost, and intangible costs associated with one 6-month injection compared with two 3-month injections. Claims data were used for the analyses of direct and indirect cost and Medical Fee Schedule Table for direct cost. Discrete choice experiments were conducted by web-based survey to determine the intangible costs. Another web-based survey was also conducted on premenopausal breast cancer patients with injections of leuprorelin acetate, to calibrate the results of discrete choice experiments.

RESULTS

The medical costs saved for having one less injection in pre-menopausal breast cancer patients with leuprorelin acetate injection were JPY 6,183. The productivity loss saving was JPY 1,419. An estimation of intangible costs saved for having one less injection of leuprorelin acetate was JPY 58,430, which included the disbenefit due to pain (JPY 8,535), injection site reactions (JPY 44,051), waiting time (JPY 9,595), and subtracting value in medical consultation (JPY 3,751). The total cost saved for having one less injection was JPY 66,032.

LIMITATIONS

The respondents from the internet panel provided by a survey company do not necessarily reflect a population of Japanese society.

CONCLUSIONS

Leuprorelin acetate 6-month depot demonstrates a higher value than leuprorelin acetate 3-month depot through saving medical costs and loss of productivity, as well as intangible costs saved for having one less injection when treating pre-menopausal breast cancer patients. In the costs for treating with leuprorelin acetate, the percentage of intangible costs might not be negligible. The intangible costs will probably be actively evaluated to proceed to patient-centered healthcare in society.

Preservation of Fertility or Ovarian Function in Patients with Breast Cancer or Gynecologic and Internal Malignancies

Because of the efficacy of systemic therapies, neoplasias which occur in pediatric and adolescent patients and in young adults have high cure rates. This means that fulfilling their wish to have children has become a more pressing concern, particularly among young women with malignant tumors. Premature ovarian failure is also a not insignificant problem as it has a lasting detrimental effect on quality of life. Every oncology patient who may potentially wish to have children should be informed about their options for preserving fertility prior to starting treatment. The rates of patient who received detailed briefing on this point remain low. This review presents the effects of different chemotherapeutic drugs on gonadal function together with an overview of currently valid recommendations on fertility preservation. Risk groups are defined and the specific approaches for malignancies of various organ systems are described. Cryopreservation of oocytes, fertilized embryos and ovarian tissue are fertility-preserving options for girls/young women. The data on the benefits of administering GnRH analogs for ovarian protection prior to starting chemotherapy are not clear. In postpubertal boys or male cancer patients, the standard approach is to cryopreserve sperm before starting therapy. The cryopreservation of testicular tissue is possible for prepubertal boys, however in-vitro sperm maturation is still in its experimental stages. This review also presents existing drug options for the preservation of ovarian function in oncology patients prior to chemotherapy, particularly for patients with (hormone-sensitive) breast cancer, and looks at the special issues of fertility-preserving surgery and radiation therapy in patients with gynecologic malignancies.