Anastrozole is superior to tamoxifen as first-line therapy for advanced breast cancer in postmenopausal women: results of a North American multicenter randomized trial. Arimidex Study Group

Comparative effectiveness analysis of survival with first-line palbociclib or ribociclib plus AI in HR + /HER2- advanced breast cancer (CEPRA study): preliminary analysis of real-world data from Thailand

BACKGROUND

The current standard first-line treatment for hormone receptor-positive/human epidermal growth factor receptor 2 negative (HR + /HER2 -) advanced breast cancer (ABC) is a combination of aromatase inhibitor (AI) plus CDK4/6 inhibitors (CDK4/6i). Direct comparison trials of different CDK4/6i are scarce. This real-world study compared the effectiveness of first-line AI plus ribociclib versus palbociclib.

METHODS

This multicenter retrospective cohort study, conducted in six cancer centers in Thailand, enrolled patients with HR + /HER2 - ABC treated with first-line AI, and either ribociclib or palbociclib. Propensity score matching (PSM) was performed. The primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), overall response rate (ORR), time to chemotherapy (TTC), and adverse events.

RESULTS

Of the 250 patients enrolled, 134 patients with ribociclib and 49 patients with palbociclib were captured after PSM. Baseline characteristics were well-balanced between groups. Median PFS in patients receiving ribociclib and palbociclib were 27.9 and 31.8 months, respectively (hazard ratio: 0.87; 0.55-1.37). The median OS in the AI + ribociclib arm was 48.7 months compared to 59.1 months in the AI + palbociclib arm (hazard ratio: 0.55; 0.29-1.05). The median TTC in the AI + palbociclib group was 56 months, but not reached in the AI + ribociclib group (p = 0.42). The ORR of AI + ribociclib and AI + palbociclib were comparable (40.5% vs. 53.6%, p = 0.29). Patients receiving palbociclib demonstrated a higher proportion of neutropenia compared to those receiving ribociclib, despite a similar dose reduction rate (p = 0.28). Hepatitis rate was similar between the ribociclib (21%) and palbociclib groups (22%). Additionally, a low incidence of QT prolongation was observed in both the ribociclib (5%) and palbociclib groups (4%).

CONCLUSION

This preliminary analysis of a real-world study demonstrated the comparable effectiveness of ribociclib and palbociclib with AI as an initial therapy for HR + /HER2 - ABC. No statistically significant difference in PFS, OS, and TTC was found in patients treated with AI combined with palbociclib or ribociclib. Longer follow-up and further prospective randomized head-to-head studies are warranted.

The impact of previous therapy on overall-survival in registration clinical trials for 1st line metastatic breast cancer a systemic review

AIM

To explore the impact of previous treatment on the efficacy of investigational new drugs in registration trials for 1st line metastatic breast cancer (MBC).

METHODS

Thirteen US Food and Drug Administration (FDA) approved indications for 1st line MBC between 1/2000-12/2023 were identified and their supporting publications were searched in the ClinicalTrials.gov and Google Scholar. Where available, hazard ratios (HRs) and 95 % confidence intervals (CI) for overall-survival (OS) were pooled into meta-analysis and the difference in the magnitude of OS benefit between treatment naïve and previously treated patients was analyzed.

RESULTS

There was no difference in the magnitude of OS benefit between treatment-naïve and previously treated patients (HR=0.72 versus 0.80,p for difference=0.25). In indications for triple-negative BC, treatment-naïve patients had higher magnitude of OS benefit compared to previously treated patients (HR=0.53 versus 0.81,p=0.03). In indications for luminal disease, the magnitude of benefit was comparable between the subgroups.

CONCLUSIONS

In trials supporting 1st line therapy for TNBC the magnitude of benefit is significantly higher in treatment naïve compared to previously treated patients. Our findings may represent a previously unrecognized bias, potentially over-estimating the benefit of triple-negative BC new drugs.

Gender minorities in breast cancer - Clinical trials enrollment disparities: Focus on male, transgender and gender diverse patients

BACKGROUND

The last years have seen unprecedented improvement in breast cancer (BC) survival rates. However, this entirely apply to female BC patients, since gender minorities (male, transgender/gender-diverse) are neglected in BC phase III registration clinical trials.

METHODS

We conducted a scoping review of phase III clinical trials of agents with a current positioning within the therapeutic algorithms of BC.

RESULTS

We selected 51 phase III trials. Men enrollment was allowed in 35.3% of trials. In none of the trial inclusion/exclusion criteria referred to transgender/gender-diverse people. A numerical higher rate of enrolled men was observed in the contemporary as compared to historical group. We found a statistically significant association between the drug class and the possibility of including men: 100%, 80%, 50%, 33.3%, 25%, 10% and 9.1% of trials testing ICI/PARP-i, ADCs, PI3K/AKT/mTOR-i, anti-HER2 therapy, CDK4/6-i, ET alone, and CT alone. Overall, 77409 patients were enrolled, including 112 men (0.2%). None of the trial reported transgender/gender-diverse people proportion. Studies investigating PARP-i were significantly associated with the highest rate of enrolled men (1.42%), while the lowest rates were observed for trials of CT (0.13%), ET alone (0.10%), and CDK 4/6-I (0.08%), p < 0.001.

CONCLUSIONS

We confirmed that gender minorities are severely underrepresented among BC registration trials. We observed a lower rate of men in trials envisaging endocrine manipulation or in less contemporary trials. This work sought to urge the scientific community to increase the awareness level towards the issue of gender minorities and to endorse more inclusive criteria in clinical trials.

Progression from ductal carcinoma in situ to invasive breast cancer: molecular features and clinical significance

Ductal carcinoma in situ (DCIS) represents pre-invasive breast carcinoma. In untreated cases, 25-60% DCIS progress to invasive ductal carcinoma (IDC). The challenge lies in distinguishing between non-progressive and progressive DCIS, often resulting in over- or under-treatment in many cases. With increasing screen-detected DCIS in these years, the nature of DCIS has aroused worldwide attention. A deeper understanding of the biological nature of DCIS and the molecular journey of the DCIS-IDC transition is crucial for more effective clinical management. Here, we reviewed the key signaling pathways in breast cancer that may contribute to DCIS initiation and progression. We also explored the molecular features of DCIS and IDC, shedding light on the progression of DCIS through both inherent changes within tumor cells and alterations in the tumor microenvironment. In addition, valuable research tools utilized in studying DCIS including preclinical models and newer advanced technologies such as single-cell sequencing, spatial transcriptomics and artificial intelligence, have been systematically summarized. Further, we thoroughly discussed the clinical advancements in DCIS and IDC, including prognostic biomarkers and clinical managements, with the aim of facilitating more personalized treatment strategies in the future. Research on DCIS has already yielded significant insights into breast carcinogenesis and will continue to pave the way for practical clinical applications.

Current Management and Future Perspectives of Hormone Receptor-Positive HER2-Negative Advanced Breast Cancer

OBJECTIVES

An overview of the best therapeutic approaches for the management of hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer is provided, and emerging treatment advances are discussed. Key nursing considerations and the role of the nurse in the provision of optimal care are explored.

DATA SOURCES

Data sources include peer-reviewed articles sourced in electronic databases.

CONCLUSION

With a multitude of current and emerging treatments for the management of hormone receptor-positive, HER2-negative advanced breast cancer, patients with this subtype have improved overall survival. It is essential that specialist nurses holistically support patients; this will ensure treatment adherence, leading to enhanced longevity and quality of life.

IMPLICATIONS FOR NURSING PRACTICE

Nurses play an important role in patient education and the early identification and management of treatment toxicities. Nurses also need to monitor and facilitate adherence by identifying barriers and implementing strategies to overcome them, ultimately improving patient outcomes.

Diabetes mellitus in breast cancer survivors: metabolic effects of endocrine therapy

Breast cancer is the most common invasive malignancy in the world, with millions of survivors living today. Type 2 diabetes mellitus (T2DM) is also a globally prevalent disease that is a widely studied risk factor for breast cancer. Most breast tumours express the oestrogen receptor and are treated with systemic therapies designed to disrupt oestrogen-dependent signalling. Since the advent of targeted endocrine therapy six decades ago, the mortality from breast cancer has steadily declined; however, during the past decade, an elevated risk of T2DM after breast cancer treatment has been reported, particularly for those who received endocrine therapy. In this Review, we highlight key events in the history of endocrine therapies, beginning with the development of tamoxifen. We also summarize the sequence of reported adverse metabolic effects, which include dyslipidaemia, hepatic steatosis and impaired glucose tolerance. We discuss the limitations of determining a causal role for breast cancer treatments in T2DM development from epidemiological data and describe informative preclinical studies that suggest complex mechanisms through which endocrine therapy might drive T2DM risk and progression. We also reinforce the life-saving benefits of endocrine therapy and highlight the need for better predictive biomarkers of T2DM risk and preventive strategies for the growing population of breast cancer survivors.

Design, structure-activity relationships, and enzyme kinetic studies of tricyclic and tetracyclic coumarin-based sulfamates as steroid sulfatase inhibitors

Inhibition of steroid sulfatase (STS) decreases estrogen production and thus, suppresses tumor proliferation. Inspired by irosustat, the first STS inhibitor in clinical trials, we explored twenty-one tricyclic and tetra-heterocyclic coumarin-based derivatives. Their STS enzyme kinetic parameters, docking models, and cytotoxicity toward breast cancer and normal cells were evaluated. Tricyclic derivative 9e and tetracyclic derivative 10c were the most promising irreversible inhibitors developed in this study, with KI of 0.05 and 0.4 nM, and kinact/KI ratios of 28.6 and 19.1 nM-1min-1 on human placenta STS, respectively.

Systemic therapy for hormone receptor-positive/human epidermal growth factor receptor 2-negative early stage and metastatic breast cancer

Hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer is defined by the presence of the estrogen receptor and/or the progesterone receptor and the absence of HER2 gene amplification. HR-positive/HER2-negative breast cancer accounts for 65%-70% of all breast cancers, and incidence increases with increasing age. Treatment varies by stage, and endocrine therapy is the mainstay of treatment in both early stage and late-stage disease. Combinations with cyclin-dependent kinase 4/6 inhibitors have reduced distant recurrence in the early stage setting and improved overall survival in the metastatic setting. Chemotherapy is used based on stage and tumor biology in the early stage setting and after endocrine resistance for advanced disease. New therapies, including novel endocrine agents and antibody-drug conjugates, are now changing the treatment landscape. With the availability of new treatment options, it is important to define the optimal sequence of treatment to maximize clinical benefit while minimizing toxicity. In this review, the authors first discuss the pathologic and molecular features of HR-positive/HER2-negative breast cancer and mechanisms of endocrine resistance. Then, they discuss current and emerging therapies for both early stage and metastatic HR-positive/HER2-negative breast cancer, including treatment algorithms based on current data.

CDK4/6 Inhibitors—Overcoming Endocrine Resistance Is the Standard in Patients with Hormone Receptor-Positive Breast Cancer

Purpose of review: Tamoxifen and aromatase inhibitors can be considered as some of the first targeted therapies. For the past 30 years, they were the endocrine treatment standard in the advanced and early breast cancer setting. CDK4/6 inhibitors, however, are the first substances in almost two decades to broadly improve the therapeutic landscape of hormone receptor-positive breast cancer patients for the upcoming years. This review is designed to discuss the recent history, current role, future directions and opportunities of this substance class. Recent findings: The CDK4/6 inhibitors abemaciclib, dalpiciclib, palbociclib and ribociclib have all demonstrated a statistically significant improvement in progression-free survival in advanced disease. However, to date, abemaciclib and ribociclib are the only CDK4/6 inhibitors to have shown an improvement in overall survival in patients with metastatic breast cancer. Moreover, abemaciclib is the first CDK4/6 inhibitor to also reduce the risk of recurrence in those with early-stage disease. Further CDK inhibitors, treatment combinations with other drugs and different therapy sequences are in development. Summary: Achieving significant improvements in survival rates in the advanced and early breast cancer treatment setting, CDK4/6 inhibitors have set a new standard of care for patients with advanced breast cancer. It remains important to better understand resistance mechanisms to be able to develop novel substances and treatment sequences.

Fe-Catalyzed Direct Synthesis of Nitriles from Carboxylic Acids with Electron-Deficient N-Cyano-N-aryl-arylsulfonamide

Established carboxylic acids to nitriles conversion methods suffer from expensive catalysts, tedious steps, high temperatures (>200 °C), high pressure, or a narrow substrate range. Herein, we demonstrate a concise and efficient access to diverse nitrile compounds from ubiquitous carboxylic acids with electron-deficient N-cyano-N-aryl-arylsulfonamide (NCAS) in moderate to excellent yields. This strategy is promoted by an inexpensive iron catalyst and is generally compatible with primary, secondary, tertiary, and aryl carboxylic acids, as well as a variety of functional groups.

Shifting Treatment Paradigms: Improvements in HR-Positive, HER-2- Negative Breast Cancer Care in Poland from a Clinical Perspective

Patients with hormone-receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer constitute about 70% of the breast cancer population. About 35% of these patients develop distant metastases and their treatment will be palliative. Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors were shown to significantly improve the outcomes of these patients. In combination with endocrine therapy, they have become the standard first-line treatment for HR-positive, HER2-negative breast cancer. In Poland, treatment with CDK4/6 inhibitors is reimbursed only for patients participating in the drug program of the Ministry of Health. However, fulfilling the eligibility criteria for the program may be challenging both for patients and for clinicians. This may lead to a delay in treatment with CDK4/6 inhibitors or a decision to use older and less effective drugs that are more widely available. The aim of this review was to compare the efficacy of first-line therapies in patients with HR-positive, HER2-negative metastatic breast cancer depending on the use of CDK4/6 inhibitors. We compared the efficacy of previous standard therapies with that of ribociclib, a CDK4/6 inhibitor, based on the median progression-free survival (PFS) as an outcome. Median PFS is not affected by the efficacy of subsequent treatment lines and is easy to interpret both for clinicians and for patients. The first-line treatment with chemotherapy or endocrine therapy (without CDK4/6 inhibitors) prolongs median PFS by several months and even to over a dozen months. The first-line treatment with endocrine therapy plus CDK4/6 inhibitors provides an opportunity to achieve a median PFS of more than 25 months and to prolong it by about 9 to 14 months.

Use of Ultrasound and Ki-67 Proliferation Index to Predict Breast Cancer Tumor Response to Neoadjuvant Endocrine Therapy

BACKGROUND

Prediction of tumor shrinkage and pattern of treatment response following neoadjuvant endocrine therapy (NET) for estrogen receptor positive (ER+), Her2 negative (Her2-) breast cancers have had limited assessment. We examined if ultrasound (US) and Ki-67 could predict the pathologic response to treatment with NET and how the pattern of response may impact surgical planning.

METHODS

A total of 103 postmenopausal women with ER+, HER2- breast cancer enrolled on the FELINE trial had Ki-67 obtained at baseline, day 14, and surgical pathology. A total of 70 patients had an US at baseline and at the end of treatment (EOT). A total of 48 patients had residual tumor bed cellularity (RTBC) assessed. The US response was defined as complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD). CR or PR on imaging and ≤70% residual tumor bed cellularity (RTBC) defined a contracted response pattern.

RESULTS

A decrease in Ki-67 at day 14 was not predictive of EOT US response or RTBC. A contracted response pattern was identified in one patient with CR and in sixteen patients (33%) with PR on US. Although 26 patients (54%) had SD on imaging, 22 (85%) had RTBC ≤70%, suggesting a non-contracted response pattern of the tumor bed. The remaining four (15%) with SD and five with PD had no response.

CONCLUSION

Ki-67 does not predict a change in tumor size or RTBC. NET does not uniformly result in a contracted response pattern of the tumor bed. Caution should be taken when using NET for the purpose of downstaging tumor size or converting borderline mastectomy/lumpectomy patients.

Challenging Endocrine Sensitivity of Hormone Receptor-Positive/HER2-Negative Advanced Breast Cancer with the Combination of Eribulin and Endocrine Therapy: The REVERT Study

BACKGROUND

Luminal advanced breast cancer (ABC) patients eventually progress on endocrine therapy. REVERT aimed to explore whether eribulin could restore endocrine sensitivity in a randomized, non-comparative phase II trial.

METHODS

Aromatase inhibitor (AI)-resistant patients with luminal ABC were randomized 1:1 to receive eribulin +/- AI. Patients were stratified by prior cyclin-dependent kinases 4/6 inhibitor (CDK4/6i) treatment. The primary endpoint was an investigator-assessed overall response rate (ORR) according to RECIST version 1.1 in the eribulin + AI arm. An interim analysis was planned with 11 evaluable patients according to a two-stage Simon design.

RESULTS

Twenty-two patients were enrolled (15 eribulin + AI arm; 7 eribulin arm). The trial was terminated early in March 2021, with eight (36.4%) patients still on treatment. ORR was 26.7% in the eribulin + AI arm (95% CI, 7.8-55.1%; p = 0.0541). In the eribulin arm, two (28.6%) patients had an objective response (95% CI, 3.7-71.0%). The difference between the study arms was not significant (p = 0.918). The addition of AI to eribulin also failed to show improvement in other efficacy endpoints. A significant interaction between the treatment arm and previous CDK4/6i treatment was observed for ORR (p = 0.018) and progression-free survival (p = 0.084). Overall, the toxicity profile was consistent with the known safety profile of eribulin. No treatment-related deaths were reported.

CONCLUSION

Eribulin + AI does not seem to improve outcomes compared with eribulin monotherapy in patients with AI-resistant luminal ABC. This chemo-endocrine approach deserves further investigation after progression to CDK4/6i-based therapy.

Aromatase Inhibitors and Risk of Metabolic and Cardiovascular Adverse Effects in Breast Cancer Patients-A Systematic Review and Meta-Analysis

Aromatase inhibitors (AIs) have been considered first-line therapy for patients with hormone-dependent breast cancer due to their high efficacy and good tolerability. However, AIs are not free of adverse events, and studies show that therapy with AIs is associated with an increased risk of cardiovascular events and the development of insulin resistance and diabetes. We searched the Cochrane Central Register of Controlled Trials, PubMed and EMBASE up to 27 October 2020 for the prevalence of cardiovascular and/or metabolic adverse effects during treatment with AIs in postmenopausal women with breast cancer. A meta-analysis was performed using a random effects model. Odds ratios and 95% confidence intervals were calculated and illustrated using forest plot charts. We performed separate analyses depending on trial design. Twenty two studies met the inclusion criteria. AIs were associated with a higher risk of cardiovascular events, especially when we compared study arms in which AIs were used (alone or in sequence with TAM) with the arms in which TAM was used alone (OR = 1.16; 95%CI 1.04-1.30) or when comparing patients taking AIs alone to patients taking TAM alone or in sequence with AIs (OR = 1.24; 95%CI 1.11-1.38). A pooled analysis of five trials comparing adjuvant AIs to TAM showed the odds for arterial hypertension being 1.31 times higher for patients taking AIs; however, this did not reach statistical significance (OR = 1.31; 95%CI 0.47-3.65). We have not shown an increased risk of dyslipidemia or weight gain with the use of AIs. Our results suggest that postmenopausal women with breast cancer treated with AIs have an increased risk of cardiovascular events in comparison with TAM, potentially due more to a cardioprotective effect of the latter than the cardiotoxicity of AIs. We were unable to prove a similar association for hypertension, dyslipidemia, hyperglycemia or weight gain. Further high-quality RCTs and post-marketing safety observational studies are needed to definitively evaluate the impact of AIs on metabolic disorders in breast cancer patients.

Comparative differential cytotoxicity of clinically used SERMs in human cancer lines of different origin and its predictive molecular docking studies of key target genes involved in cancer progression and treatment responses

SERMS like Tamoxifene, 5-hydroxy tamoxifene, raloxifene and endoxifene has been used for the treatment of hormonal imbalances and dependent cancers owing to their action via Estrogen receptors as in the treatment of estrogen sensitive breast cancers. Due to the adverse side effects, modifications and development of the existing or newer SERMS has always been of immense interest. Ormeloxifene, a SERM molecule manufactured by HLL Lifecare Ltd, India as birth control under the trade names Saheli, Novex, and Novex-DS which is also investigated against mastalgia, fibro-adenoma and abnormal uterine bleeding. Anti-cancer effects have been reported in estrogen dependent and independent cancers which shows its wide scope to be implemented in cancer therapy. Current investigation is a comprehensive effort to find the cytotoxic potential of Ormeloxifene in comparison with clinically used four SERMS in twenty six cancer cell lines of different origin using Adriamycin as positive control. Also the computational studies pertaining to selected target/ligand with respect to tumor progression, development, treatment responses and apoptosis. The studies proved effective cytotoxicity of Ormeloxifene on cancer cell lines with lower TGI, GI50 and LC50 values which are significantly comparable. Also the in silico studies proved that the docking score of the compound suggests the interaction of the compound which could tightly regulate key target genes controlling cancer like ER, EGFR kinase, EGFR-cSRC, HDAC-2, PARP-1 and BRAF. This study brings out the superior efficacy of Ormeloxifene compared to other SERMS with proven safety profile to be repositioned as an anti-cancer drug to treat diverse cancer types.

Endocrine Treatment for Breast Cancer Patients Revisited-History, Standard of Care, and Possibilities of Improvement

PURPOSE OF REVIEW

Due to the findings of current studies and the approval of novel substances for the therapy of hormone-receptor-positive breast cancer patients, the established standards of endocrine treatment are changing. The purpose of this review is to give an overview of the history of endocrine treatment, to clarify its role in the present standard of care, and to discuss the possibilities of improvement.

RECENT FINDINGS

Tamoxifen, aromatase inhibitors, and fulvestrant are the main drugs that have been used for decades in the therapy of hormone-receptor-positive breast cancer patients. However, since a relevant number of women suffer at some point from disease recurrence or progression, several novel substances are being investigated to overcome resistance mechanisms by interfering with certain signaling pathways, such as the PI3K/AKT/mTOR or the CDK4/6 pathways. mTOR and CDK4/6 inhibitors were the first drugs approved for this purpose and many more are in development.

SUMMARY

Endocrine treatment is one of the best tolerable cancer therapies available. Continuous investigation serves to improve patients' outcomes and modernize the current standard of care. Considering the resistance mechanisms and substances analyzed against these, endocrine treatment of hormone-receptor-positive breast cancer is on the brink of a new era.

Oestrogen deprivation induces chemokine production and immune cell recruitment in in vitro and in vivo models of oestrogen receptor-positive breast cancer

Background

Oestrogen receptor-positive (ER+) breast cancer is commonly treated using endocrine therapies such as aromatase inhibitors which block synthesis of oestradiol, but the influence of this therapy on the immune composition of breast tumours has not been fully explored. Previous findings suggest that tumour infiltrating lymphocytes and immune-related gene expression may be altered by treatment with aromatase inhibitors. However, whether these changes are a direct result of impacts on the host immune system or mediated through tumour cells is not known. We aimed to investigate the effect of oestrogen deprivation on the expression of chemokines and immune infiltration in vitro and in an ER+ immunocompetent mouse model.

Methods

RT-qPCR and a bead-based Bioplex system were used to investigate the expression of chemokines in MCF-7 breast cancer cells deprived of oestrogen. A migration assay and flow cytometry were used to measure the migration of human peripheral blood mononuclear cells (PBMCs) to MCF-7 cells grown without the main biologically active oestrogen, oestradiol. Using flow cytometry and immunohistochemistry, we examined the immune cell infiltrate into tumours created by injecting SSM3 ER+ breast cancer cells into wild-type, immunocompetent 129/SvEv mice.

Results

This study demonstrates that oestrogen deprivation increases breast cancer secretion of TNF, CCL5, IL-6, IL-8, and CCL22 and alters total human peripheral blood mononuclear cell migration in an in vitro assay. Oestrogen deprivation of breast cancer cells increases migration of CD4+ T cells and decreases migration of CD11c+ and CD14+ PBMC towards cancer cells. PBMC migration towards breast cancer cells can be reduced by treatment with the non-steroidal anti-inflammatory drugs, aspirin and celecoxib. Treatment with endocrine therapy using the aromatase inhibitor letrozole increases CD4+ T cell infiltration into ER+ breast cancer tumours in immune competent mice.

Conclusions

These results suggest that anti-oestrogen treatment of ER+ breast cancer cells can alter cytokine production and immune cells in the area surrounding the cancer cells. These findings may have implications for the combination and timing of anti-oestrogen therapies with other therapies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01472-1.

Quality of life of therapies for hormone receptor positive advanced/metastatic breast cancer: Regulatory aspects and clinical impact in Europe

In recent years, the number of trials incorporating health-related quality of life (HRQoL) data has increased. The impact of HRQoL on regulatory decision making in the European context and on clinical practice is not well established. We conducted an analysis of the role of QoL data extracted from the clinical trials of the drugs approved for hormone receptor positive/HER2-negative advanced/metastatic breast cancer (mBC). The results from the HRQoL were collected and a meta-analysis was performed to evaluate the impact of experimental drugs compared to standard treatments. The results showed a non-detrimental effect in HRQoL from the new treatments. As regards the approval process, from an examination of the European Medicine Agency (EMA) documents, HRQoL was reported nonextensively and contained and discussed in the European assessment reports (EPARs) for eleven trials in the approval process and cited in three cases in the EPARs and summary of medicinal product characteristics (SmPC). An effort should be made by all the stakeholders to increase the visibility of the HRQoL results in order to allow increased consideration in the approval process to make QoL data more easily and visibly available for the clinician and the patients. The evaluation should be reflected in the SmPC in order to increase the amount of information provided to the physician.

Management of hormone receptor-positive, human epidermal growth factor 2-negative metastatic breast cancer

Estrogen receptor (ER) is the major driver of most metastatic breast cancers (mBCs). Endocrine therapy (ET) is the most effective treatment for ER + mBC, but its effectiveness is limited by high rates of de novo and acquired resistance. A growing understanding of the biological characteristics and complexity of the ER pathway and the mechanisms of ET resistance has led to the development of a new generation of targeted therapies. One such mechanism is the cell cycle signaling pathways, which lead to the development of cyclin-dependent kinase 4/6 inhibitors (CDK4/6is) that have, in turn, transformed the management of such tumors. Another important mechanism is the alteration of the phosphatidylinositol 3'-kinase/AKT/mammalian target of rapamycin pathway. Drugs targeting each component of these pathways are currently used in clinical practice, and several more are in development. As a result, a myriad of new targeted therapies are consistently being added to the clinical oncologist armamentarium. Navigating the evolving and highly complex treatment landscape of HR + /HER2- mBC remains both an art and a challenge. In this review, we discuss the biological features of HR + /HER2- mBC and the different mechanisms of resistance to ET. We also discuss the management of mBC as the disease changes from endocrine-sensitive to endocrine-resistant.

From clinical trials to clinical practice: the use of everolimus and exemestane in the treatment of hormone receptor-positive metastatic breast cancer: real-world data

Everolimus combined with exemestane can modulate endocrine resistance. The combination showed significant improvement in progression-free survival (PFS) in phase III clinical trials for hormone receptor positive metastatic breast cancer patients. It also showed serious adverse events. We evaluate the efficacy and prevalence of serious adverse events in a real-world setting. We retrospectively examined 91 breast cancer patients; all were previously treated with chemotherapy and fulvestrant (84% and 59%, respectively). After a 13-month median follow-up, 29% had a partial response, and 32% had stable disease. The PFS was 7.8 months. Due to adverse events, 19% of patients stopped the treatment, while 31% required a dose reduction. Despite enrolling heavier-pretreated patients, our real-world outcome for the efficacy and safety of the exemestane and everolimus match those of the clinical trials. Such results should assure clinicians and lead to wider adoption of this oral, chemotherapy-sparing regimen.

Optimizing treatment selection, and sequencing decisions for Management of HR-Positive, HER2-Negative advanced breast cancer - Proceedings from breast cancer expert group meeting

PURPOSE

The therapeutic landscape of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (mBC) has evolved considerably with the introduction of newer targeted agents and their combinations with endocrine therapies. In this scenario, optimizing treatment selection and sequencing is daunting for clinicians. The purpose of this review is to provide evidence-based answers to key clinical questions on treatment selection and sequencing for the management of HR + HER2 - mBC.

DESIGN

A panel of nine key opinion leaders from Argentina, Brazil, Colombia, Mexico, Moscow, Singapore, South Korea, Taiwan, and UAE convened in October 2018. They reviewed the literature and formulated answers to clinical questions on optimizing the management of HR + HER2 - mBC.

RESULTS

Evidence-based answers were formulated for: (1) optimal initial treatment choice; (2) ovarian function suppression, optimal endocrine partner, and role of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors (in premenopausal women); (3) better first-line standard of care than aromatase inhibitors; (4) preferred second-line treatment; (5) treatment of oligometastatic disease; (6) factors influencing first-line single-agent endocrine therapy choice; (7) influence of endocrine resistance on treatment selection; (8) optimal maintenance regimen in visceral crisis; and (9) need for a breast cancer registry for patients with HR + HER2 - mBC. The panel also proposed a treatment-sequencing algorithm for the management of HR + HER2 - mBC.

CONCLUSION

The current article will serve as a comprehensive guide for optimizing the management of HR + HER2 - mBC. The proposed breast cancer registry will help identify unmet needs and develop strategic regional policies to help improve access to optimized care for HR + HER2 - mBC.

Current and emerging estrogen receptor-targeted therapies for the treatment of breast cancer

Nearly 80% of all breast cancers are estrogen receptor positive (ER+) and require the activity of this transcription factor for tumor growth and survival. Thus, endocrine therapies, which target the estrogen signaling axis, have and will continue to be the cornerstone of therapy for patients diagnosed with ER+ disease. Several inhibitors of ER activity exist, including aromatase inhibitors (AIs), selective estrogen receptor modulators (SERMs), selective estrogen receptor degraders/down-regulators (SERDs), and ER proteolysis-targeting chimeras (ER PROTACs); drugs which differ in the mechanism(s) by which they inhibit this signaling pathway. Notwithstanding their significant impact on the management of this disease, resistance to existing endocrine therapies remains a major impediment to durable clinical responses. Although the mechanisms of resistance are complex and varied, dependence on ER is typically retained after progression on SERMs and AIs, suggesting that ER remains a bona fide therapeutic target. The discovery and development of orally bioavailable drugs that eliminate ER expression (SERDs and ER PROTACs) will likely aid in treating this growing patient population. All of the existing endocrine therapies were developed with the intent of inhibiting the cancer cell intrinsic actions of ER and/or with the objective of achieving extreme estrogen deprivation and most achieve that goal. A longstanding question that remains to be addressed, however, is how actions of existing interventions extrinsic to the cancer cells influence tumor biology. We believe that these issues need to be addressed in the development of strategies to develop the next generation of ER-modulators optimized for positive activities in both cancer cells and other cells within the tumor microenvironment (TME).

Phase Ib Study of the Oral Proteasome Inhibitor Ixazomib (MLN9708) and Fulvestrant in Advanced ER+ Breast Cancer Progressing on Fulvestrant

LESSONS LEARNED

Fulvestrant is a selective estrogen receptor (ER)-downregulating antiestrogen that blocks ER transcriptional activity and is approved for ER-positive breast cancer. Fulvestrant also induces accumulation of insoluble ER and activates an unfolded protein response; proteasome inhibitors have been shown to enhance these effects in preclinical models.

BACKGROUND

Fulvestrant is a selective estrogen receptor (ER)-downregulating antiestrogen that blocks ER transcriptional activity and is approved for ER-positive (+) breast cancer. Fulvestrant also induces accumulation of insoluble ER and activates an unfolded protein response; proteasome inhibitors have been shown to enhance these effects in preclinical models.

METHODS

This is a single-center phase Ib study with a 3+3 design of fulvestrant and the proteasome inhibitor ixazomib (MLN9708) in patients with advanced ER+ breast cancer that was progressing on fulvestrant. A dose-escalation design allowed establishment of the ixazomib maximum tolerated dose (MTD). Secondary objectives included progression-free survival, pharmacokinetics, and tumor molecular analyses.

RESULTS

Among nine evaluable subjects, treatment was well-tolerated without dose-limiting toxicities The MTD of ixazomib was 4 mg in combination with fulvestrant. Plasma concentrations of the active form of ixazomib (MLN2238) in the 4-mg dose cohort had a median (range) maximal concentration (Cmax ) of 155 (122-171) ng/mL, time of maximal concentration (Tmax ) of 1 (1-1.5) hour, terminal elimination half-life of 66.6 (57.3-102.6) hour after initial dose, and area under the curve (AUC) of 5,025 (4,160-5,345) ng*h/mL. One partial response was observed, and median progression-free survival was 51 days (range, 47-137).

CONCLUSION

This drug combination has a favorable safety profile and antitumor activity in patients with fulvestrant-resistant advanced ER+ breast cancer that justifies future testing.

Endocrine-Based Treatments in Clinically-Relevant Subgroups of Hormone Receptor-Positive/HER2-Negative Metastatic Breast Cancer: Systematic Review and Meta-Analysis

A precise assessment of the efficacy of first-/second-line endocrine therapies (ET) ± target therapies (TT) in clinically-relevant subgroups of hormone receptor-positive (HR+)/HER2-negative metastatic breast cancer (MBC) has not yet been conducted. To improve our current knowledge and support clinical decision-making, we thus conducted a systematic literature search to identify all first-/second-line phase II/III randomized clinical trials (RCT) of currently approved or most promising ET ± TT. Then, we performed a meta-analysis to assess progression-free (PFS) and/or overall survival (OS) benefit in several clinically-relevant prespecified subgroups. Thirty-five RCT were included (17,595 patients). Pooled results show significant reductions in the risk of relapse or death of 26-41% and 12-27%, respectively, depending on the clinical subgroup. Combination strategies proved to be more effective than single-agent ET (PFS hazard ratio (HR) range for combinations: 0.60-0.65 vs. HR range for single agent ET: 0.59-1.37; OS HR range for combinations: 0.74-0.87 vs. HR range for single agent ET: 0.68-0.98), with CDK4/6-inhibitors(i) + ET being the most effective regimen. Single agent ET showed comparable efficacy with ET+TT combinations in non-visceral (p = 0.63) and endocrine sensitive disease (p = 0.79), while mTORi-based combinations proved to be a valid therapeutic option in endocrine-resistant tumors, as well as PI3Ki + ET in PIK3CA-mutant tumors. These results strengthen international treatment guidelines and can aid therapeutic decision-making.

Safety and efficacy of everolimus (EVE) plus exemestane (EXE) in postmenopausal women with locally advanced or metastatic breast cancer: final results from EVEREXES

BACKGROUND

This study was conducted to collect clinical safety, tolerability, and efficacy data with the use of everolimus (EVE) combined with exemestane (EXE) in patients with advanced breast cancer (ABC).

METHODS

The EVEREXES trial initiated in 2012, provided early access to the first dual blockade treatment with EVE + EXE in patients with HR+, HER2 - ABC in Asia and other emerging growth countries. Postmenopausal women with HR+, HER2 - ABC who had documented recurrence or progression, following a nonsteroidal aromatase inhibitor therapy, were treated with EVE (10 mg/day) + EXE (25 mg/day) orally.

RESULTS

A total of 235 patients received ≥ 1 dose of study medication. At the end of the study, all patients ceased the treatment. Disease progression (66.0%) was the primary reason of discontinuation. The most common AEs (≥ 20%) were stomatitis, decreased appetite, hyperglycemia, rash, aspartate aminotransferase increased, anemia, alanine aminotransferase increased, cough, and fatigue. No new safety concerns were identified in the current study. Median progression-free survival (PFS) in the Asian subset was similar to that of the overall population (9.3 months in both groups). Confirmed overall response rate (ORR) was achieved for 19.6% of the patients. Efficacy of EVE + EXE across subgroups (prior CT, line of treatment, and presence of visceral metastases) was maintained.

CONCLUSION

The safety and efficacy results from EVEREXES trial are consistent to data previously reported in BOLERO-2. These results support that EVE + EXE could be a viable treatment option for the postmenopausal women with HR+, HER2 - ABC in Asian region.

Breast cancer liver metastasis: current and future treatment approaches

Nearly all fatalities arising from breast tumors are attributable to distant metastases. Breast cancer liver metastasis (BCLM) is associated with poor prognoses, with the median survival time being 2 to 3 years. Tumor intrinsic subtype directs preferential metastasis to specific organs, with HER2-enriched tumors demonstrating the highest rates of metastasis to the liver, though all subtypes can grow in the liver. There is no singular established standard-of-care for BCLM; therapeutic selection is driven by histologic and molecular hallmarks of the primary tumor or biopsied metastasis samples. Given the poor prognosis of patients with hepatic spread, pre-clinical studies are necessary to identify and evaluate promising new treatment strategies. It is critical that these laboratory studies accurately recapitulate the BCLM disease process, standard progression, and histological attributes. In this review, we summarize the histologic and molecular characteristics of BCLM, evaluate the efficacy of existing surgical and medical treatment strategies, and discuss future approaches to preclinical study of BCLM.

Meta-analyses of visceral versus non-visceral metastatic hormone receptor-positive breast cancer treated by endocrine monotherapies

Endocrine therapy (ET) is recommended as first-line therapy for the majority of patients with hormone receptor-positive (HR+), human epidermal growth factor 2-negative advanced breast cancer (ABC); however, the efficacy of ET in patients with visceral metastases (VM) versus patients whose disease is limited to non-visceral metastases (non-VM) is debated. Meta-analyses including available data from randomised controlled trials of first- and second-line endocrine monotherapies for patients with HR+ ABC were performed to address this question. In one and two-stage meta-analyses, progression-free survival (PFS), overall survival (OS), clinical benefit rate (CBR) and duration of clinical benefit (DoCB) outcomes were analysed. In the first-line meta-analysis (seven trials; n = 1988) tamoxifen and fulvestrant significantly improved PFS, OS and CBR for patients with non-VM versus those whose disease included VM. The most substantial hazard ratios were observed for fulvestrant 500 mg; 0.56 (95% confidence interval [CI] 0.45-0.70) and 0.55 (95% CI 0.42-0.72) for PFS and OS, respectively. In the second-line meta-analysis (seven trials; n = 2324), all ET combined was more effective (in terms of PFS, OS and DoCB) for non-VM versus VM. In both meta-analyses, patients with non-liver VM had better clinical outcomes than patients with liver VM for all types of ET. Patients whose disease included non-VM sites had better clinical outcomes with endocrine monotherapy compared with patients whose disease included VM. These findings may facilitate better informed treatment decision-making.

Meta-analyses of phase 3 randomised controlled trials of third generation aromatase inhibitors versus tamoxifen as first-line endocrine therapy in postmenopausal women with hormone receptor-positive advanced breast cancer

BACKGROUND

Four randomised controlled trials (RCTs) in postmenopausal women with advanced breast cancer (ABC) comparing aromatase inhibitors (AIs) versus the selective estrogen receptor modulator tamoxifen, each individually reported significantly longer progression-free survival (PFS) but none showed a significant difference in overall survival (OS). In these trials between 6.8% and 55% of tumours were hormone receptor (HR) status unknown or negative. This meta-analysis restricted the comparison to HR-positive (HR+) tumours.

METHODS

Anonymised individual patient data were obtained from three RCTs, EORTC (exemestane versus tamoxifen), Study 0027 and Study 0030 (both anastrozole versus tamoxifen). For the remaining RCT (Femara Study PO25; letrozole versus tamoxifen), odds ratio (OR) or hazard ratio (HzR), with confidence intervals were obtained from the clinical study report, for patients with HR+ tumours, in addition to published data. In total, data were obtained from 2296 patients; 1560 (68%) had HR+ ABC.

FINDINGS

The OR for clinical benefit rate was 1.56, in favour of AIs (p < 0.001). The duration of clinical benefit was not significantly increased by AIs (HzR 0·88; p = 0.08). For PFS the HzR (0.82) was in favour of AIs (p = 0·007). However, for OS the HzR (1.05) was not significantly different between AIs and tamoxifen (p = 0.42).

INTERPRETATION

Although third generation AIs put significantly more patients into 'clinical benefit', their tumours were not controlled for significantly longer. Overall, while this resulted in a significantly greater PFS in favour of the AIs, this did not translate into improvement in OS.

[Hot flushes and breast cancer with positive hormone receptors: Mechanisms and management]

Breast cancer is the most frequently diagnosed cancer in women and the first cause of cancer death in France. Among the different subtypes of breast cancer, the predominant form is characterized by positive hormone receptors (more than 70% of breast cancers). Hormone therapy thus plays a key role in the strategy of management of these cancers both in adjuvant and metastatic situations. The two types of adjuvant hormone therapy used are selective estrogen receptor modulators and aromatase inhibitors. Fulvestrant, an anti-estrogen, is used alone or in combination with other molecules in metastatic situations. Hot flashes are one of the symptoms most frequently reported by patients under hormone therapy. Hormone replacement therapy, which is currently the most effective treatment for hot flashes, is contraindicated in patients with a personal history of breast cancer. Various therapeutic classes of drugs have been tested in this indication but without real efficacy in the various studies carried out to date, and moreover associated with non-negligible side effects. The recent discovery of the implication of the kisspeptin system located at the hypothalamic level in the mechanism of genesis of hot flashes opens the way to possible new symptomatic treatments for hot flashes. Neurokinin 3 receptor antagonists have shown encouraging preliminary results in postmenopausal cancer-free patients and could be considered in patients in hormonal therapy for breast cancer. Broader additional studies are needed to confirm these initial results.

Management of ER positive metastatic breast cancer

There are over 2 million cases a year of breast cancer, leading to over 600,000 deaths globally [1]. Despite these large numbers, increasingly more women are being cured with early stage disease and women with advanced disease are living longer [2]. The appreciation for molecular subtypes of the disease has led to significant therapeutic advances and estrogen receptor positive (ER+) breast cancer represents the largest of these subgroups. An appreciation for the importance of estrogen signaling in ER+ dates back to 1896 when Dr. George Thomas Beatson observed impressive disease responses after performing bilateral oophorectomy in 3 women at Glasgow Cancer Hospital [3]. The evolution of treatment for advanced disease from progestins, to the selective estrogen receptor modulator tamoxifen, and subsequently the aromatase inhibitors and the selective estrogen receptor degrader fulvestrant, has been accompanied by improved efficacy and decreased side effects. While the use of these drugs has changed the natural history of both early and advanced disease, it has been long recognized that many patients will develop resistance to this approach. After many years of trying to improve on single-agent endocrine treatment, since 2012 there has been an explosion of new drugs that have shown improved efficacy in combination with endocrine approaches. The first of these to receive FDA approval was the mTOR inhibitor everolimus (2012) [4], followed by the approval of 3 cyclin-dependent kinase 4 and 6 (CDK 4/6) inhibitors [palbociclib (2015) [5], ribociclib (2018) [6], and abemaciclib (2018) [7]], and more recently the PI3-kinase inhibitor alpelisib (2019) [8]. In addition, chemotherapy is still used frequently when endocrine manipulations have been exhausted. Like other incurable malignancies, the goal in advanced ER+ breast cancer is to prolong survival and maintain quality of life. Currently, we have more tools available to achieve this than ever before and we will review the efficacy and side effect data with these agents that are driving physician choices for individual patients.

Palbociclib and beyond for the treatment of HR + HER2- metastatic breast cancer: an Asian-Pacific perspective and practical management guide on the use of CDK4/6 inhibitors

Breast cancer is the most frequent cancer amongst women worldwide including in Asia where the incidence rate is rapidly increasing. Even with treatment, around 30% of patients with early breast cancer progress to metastatic disease, with hormone receptor positive (HR+) and human epidermal growth factor receptor 2 negative (HER2-) breast cancer the most common phenotype. First-line endocrine therapy targeting the estrogen receptor signaling pathway provides a median progression-free survival or time to progression of 6-15 months in HR + HER2- metastatic breast cancer. Recently, cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors, combined with endocrine therapy, have achieved more than two years median progression-free survival in HR + HER2- metastatic breast cancer. However, the characteristics of the Asian breast cancer population differ from those of Western populations and need to be considered when selecting a suitable treatment. Breast cancer is diagnosed at a younger age in Asian populations and late stage at presentation is generally more common in low-/middle-income countries than high-income countries. Consequently, the proportion of premenopausal women with metastatic breast cancer is higher in Asian compared with Western populations. While CDK4/6 inhibitors have been approved in the USA (FDA) since 2015, experience with them in Asia is more limited. We review the experience with the CDK4/6 inhibitor palbociclib in Asian patients with HR + HER2- metastatic breast cancer and provide guidance on the use of palbociclib in these patients.

Neoadjuvant Endocrine Therapy in Breast Cancer: Current Knowledge and Future Perspectives

In locally advanced (LA) breast cancer (BC), neoadjuvant treatments have led to major achievements, which hold particular relevance in HER2-positive and triple-negative BC. Conversely, their role in hormone receptor positive (HR+), hormone epidermal growth factor 2 negative (HER2-) BC is still under debate, mainly due to the generally low rates of pathological complete response (pCR) and lower accuracy of pCR as predictors of long-term outcomes in this patient subset. While administration of neoadjuvant chemotherapy (NCT) in LA, HR+, HER2- BC patients is widely used in clinical practice, neoadjuvant endocrine therapy (NET) still retains an unfulfilled potential in the management of these subgroups, particularly in elderly and unfit patients. In addition, NET has gained a central role as a platform to test new drugs and predictive biomarkers in previously untreated patients. We herein present historical data regarding Tamoxifen and/or Aromatase Inhibitors and a debate on recent evidence regarding agents such as CDK4/6 and PI3K/mTOR inhibitors in the neoadjuvant setting. We also discuss key issues concerning the optimal treatment length, appropriate comparisons with NCT efficacy and use of NET in premenopausal patients.

Tumor Necrosis Factor α Blockade: An Opportunity to Tackle Breast Cancer

Breast cancer is the most frequently diagnosed cancer and the principal cause of mortality by malignancy in women and represents a main problem for public health worldwide. Tumor necrosis factor α (TNFα) is a pro-inflammatory cytokine whose expression is increased in a variety of cancers. In particular, in breast cancer it correlates with augmented tumor cell proliferation, higher malignancy grade, increased occurrence of metastasis and general poor prognosis for the patient. These characteristics highlight TNFα as an attractive therapeutic target, and consequently, the study of soluble and transmembrane TNFα effects and its receptors in breast cancer is an area of active research. In this review we summarize the recent findings on TNFα participation in luminal, HER2-positive and triple negative breast cancer progression and metastasis. Also, we describe TNFα role in immune response against tumors and in chemotherapy, hormone therapy, HER2-targeted therapy and anti-immune checkpoint therapy resistance in breast cancer. Furthermore, we discuss the use of TNFα blocking strategies as potential therapies and their clinical relevance for breast cancer. These TNFα blocking agents have long been used in the clinical setting to treat inflammatory and autoimmune diseases. TNFα blockade can be achieved by monoclonal antibodies (such as infliximab, adalimumab, etc.), fusion proteins (etanercept) and dominant negative proteins (INB03). Here we address the different effects of each compound and also analyze the use of potential biomarkers in the selection of patients who would benefit from a combination of TNFα blocking agents with HER2-targeted treatments to prevent or overcome therapy resistance in breast cancer.

Breast Cancer, Version 3.2020, NCCN Clinical Practice Guidelines in Oncology

Several new systemic therapy options have become available for patients with metastatic breast cancer, which have led to improvements in survival. In addition to patient and clinical factors, the treatment selection primarily depends on the tumor biology (hormone-receptor status and HER2-status). The NCCN Guidelines specific to the workup and treatment of patients with recurrent/stage IV breast cancer are discussed in this article.

Quality of life and psychological functioning in postmenopausal women undergoing aromatase inhibitor treatment for early breast cancer

INTRODUCTION

Aromatase inhibitors (AIs) dramatically increased breast cancer (BC) survival, leading to enhanced attention to their long-term consequences on psychological functioning. Conflicting data has been examined regarding the association between AIs administration and the clinical psychological features in BC survivors (BCSs).

PURPOSE

As psychological symptoms often occur in such chronic diseases, our study aimed at exploring anxious and depressive symptoms and the perceived quality of life (QoL) in BCSs assessed for osteoporosis.

METHODS

The total sample consisted of a clinical sample of 51 outpatient postmenopausal women, diagnosed with BC, and a control group composed of 51 healthy postmenopausal women. All recruited participants were evaluated through the clinical gold standard interview and completed the following self-rating scales: the Hamilton Anxiety Rating Scale, Beck Depression Inventory II edition, and 36-Item Short Form Health Survey, which were administered at baseline and after 6 months in BCSs in AIs treatment, compared with controls. Moreover, all participants were assessed for vitamin D status, bone mineral density (BMD) and subclinical vertebral fractures. Data regarding age, age at menopause, body mass index (BMI), smoking habits and alcohol consumption was collected.

RESULTS

BCSs (n = 51) showed higher anxious and depressive symptoms, and lower perceived QoL vs. controls (n = 51) (p<0.05 for all). After 6 months of treatment with AIs, BCSs showed significant reduction of anxious and depressive symptoms and a significantly higher perceived QoL for both physical and mental components, vs. controls.

CONCLUSIONS

The improvement of clinical psychological features and perceived QoL was associated with AIs treatment in women being treated with, for early breast cancer. Further studies are needed to obtain a deeper comprehension of the correlation between clinical psychological and physical features in BCSs.

CDK4/6 inhibitors in breast cancer - from in vitro models to clinical trials

Background: Breast cancer (BC) is one of the leading causes of cancer-related deaths worldwide. Standard therapies aim to disrupt pathways that regulate the growth and survival of BC cells. Therapeutic agents such as endocrine therapy target hormone dependent cancer cells and have shown to be suitable approaches in BC treatment. However, in the case of metastatic BC, curative options are limited, thus strategies have been explored to improve survival and clinical benefit. In this review we provide an up to date overview of the development of anti-cancer agents, particularly the newly developed CDK4/6 inhibitors.Material and methods: A search of PubMed was conducted to identify preclinical data surrounding the development of endocrine therapy and CDK4/6 inhibitors in early and metastatic BC. Clinical data were also sought using PubMed and clinicaltrials.gov.Results: Agents targeting oestrogen and its receptor have demonstrated positive outcomes in clinical trial with improvements in objective responses and overall survival. However, patients do exhibit adverse effects and some will eventually fail to respond to endocrine therapy. Subsequently, the development and success of 3rd generation CDK4/6 inhibitors in preclinical studies has allowed their introduction in clinical studies. In patients with ER + BC, CDK4/6 have demonstrated dramatic improvements in progression free survival when used in combination with endocrine therapies. Similar findings were also observed in metastatic disease. Adverse effects were limited in CDK4/6 treated patients, demonstrating the safety of these agents.Conclusion: CDK4/6 inhibitors are highly specific making them a safe and viable therapeutic for BC and there is increasing evidence of their potential to improve survival, even in the metastatic setting. Although a number of trials have demonstrated this, as a lone therapy or in combination, optimisation of treatment scheduling are still required in further clinical investigations.

Comparative Efficacy of CDK4/6 Inhibitors Plus Aromatase Inhibitors Versus Fulvestrant for the First-Line Treatment of Hormone Receptor-Positive Advanced Breast Cancer: A Network Meta-Analysis

BACKGROUND

Several endocrine therapies are available for postmenopausal women with hormone receptor-positive (HR +) advanced breast cancer (ABC). Given the absence of direct comparisons between fulvestrant and cyclin-dependent kinase 4/6 inhibitors (CDK4/6is) in combination with aromatase inhibitors (AIs), which are both used as standard first-line treatments for ABC, an indirect comparison using a network meta-analysis may be advantageous for decision making.

OBJECTIVE

We performed a network meta-analysis to compare the efficacies of fulvestrant and CDK4/6is plus AIs as the first-line treatment of postmenopausal breast cancer patients.

PATIENTS AND METHODS

In order to compare these treatments, we searched the PubMed, Cochrane Library, and EMBASE databases for randomized controlled trials of first-line endocrine treatment for advanced or metastatic breast cancer until October 2018. We included a total of 11 eligible trials with 5448 patients. The hazard ratios (HRs) for the efficacies of the different treatments were used as inputs in the network meta-analysis.

RESULTS

In the overall analysis, CDK4/6is plus AIs, including palbociclib plus letrozole, ribociclib plus letrozole, and abemaciclib plus nonsteroidal AI (letrozole or anastrozole), are all superior to 500 mg fulvestrant (HR = 0.50, 95% confidence interval [CI] 0.37-0.68; HR = 0.50, 95% CI 0.35-0.71; and HR = 0.49, 95% CI 0.34-0.71; respectively).

CONCLUSIONS

Within the limitations of this network meta-analysis, the comparison indicates that CDK4/6is plus AIs might represent a better option for HR+ ABC as a first-line endocrine treatment compared with fulvestrant.

Understanding the benefits and challenges of first-line cyclin-dependent kinases 4 and 6 inhibitors in advanced breast cancer among postmenopausal women

Endocrine therapy (ET) has been regarded for many years as the standard treatment for patients with hormone receptor-positive (ER+), HER2-negative (HER2-) advanced breast cancer (ABC) without visceral crisis. However, the efficacy of single-agent ET is constrained by the development of resistance, attributed to alterations in several intracellular signaling pathways, including those related to cell cycle dysregulation. The cyclin-dependent kinases 4 and 6 (CDK4/6) are principal regulators of cell cycle progression from the G1-phase into the DNA synthesis (S)-phase. In vitro inhibition of CDK4/6 activity has potent antiproliferative properties against luminal breast cancer cell lines, which are enhanced when combined with traditional ET. This has led to a substantial interest in targeting this pathway to overcome endocrine resistance in the clinic. Three selective CDK4/6 inhibitors (palbociclib, ribociclib, and abemaciclib) have been approved as first-line therapy in combination with an aromatase inhibitor, or fulvestrant in the case of ribociclib in patients with ER+/HER2- ABC. To date, there is no clue as to which subgroup of patients might benefit most from these combinations. Here, we outline some of the established approaches to overcome endocrine resistance, with special emphasis on the unique mechanism of action of CDK4/6 inhibitors.

Metronomic capecitabine with aromatase inhibitors for patients with metastatic hormone-receptor positive, HER2-negative breast cancer

Aim: To evaluate the efficacy and safety of combined metronomic capecitabine with aromatase inhibitors (AIs) for patients with newly diagnosed metastatic hormone-receptor positive, HER2-negative breast cancer. Patients & methods: A total of 41 women with a diagnosis of metastatic hormone-receptor positive, HER2-negative breast cancer received oral metronomic capecitabine, 500 mg/m2 twice daily combined with an AI. Results: After a median follow-up of 24 months (9–50), a median of 15 months of treatment were completed, the median time to progression was 15 months (12.6–17.3) and the median overall survival was 37 months (23.6–50.4). The treatment was tolerated with less than 10% grade 3 toxicities. Conclusion: Combination of metronomic capecitabine and AIs appears to be safe and has encouraging results in advanced hormone-receptor positive, HER2-negative breast cancer.

Fulvestrant for Untreated Hormone-Receptor Positive Locally Advanced or Metastatic Breast Cancer: An Evidence Review Group Perspective of a NICE Single Technology Appraisal

Clinical and cost-effectiveness evidence on fulvestrant for untreated hormone-receptor positive locally advanced or metastatic breast cancer was submitted to the single technology appraisal process of the National Institute for Health and Care Excellence by the manufacturer of fulvestrant. The Southampton Health Technology Assessments Centre was commissioned by the National Institute for Health and Care Excellence as an independent Evidence Review Group to critique the company's submitted evidence. Fulvestrant was compared directly with anastrozole in two randomised controlled trials and was compared indirectly by means of a network meta-analysis with anastrozole, letrozole and tamoxifen. This article summarises the Evidence Review Group's review of the company's submission and summarises the guidance the National Institute for Health and Care Excellence Appraisal Committee issued in January 2018. The Evidence Review Group had several concerns, the most important of which related to the degree to which fulvestrant might confer a benefit in overall survival. This was because mature data were not available from the key phase III trial FALCON. The economic model was sensitive to changes in overall survival and the Evidence Review Group considered the incremental cost-effectiveness ratio was uncertain and likely to increase once mature results from FALCON become available. The National Institute for Health and Care Excellence Appraisal Committee concluded that fulvestrant could not be recommended for treating locally advanced or metastatic estrogen-receptor-positive breast cancer in postmenopausal women who have not received previous endocrine therapy.

Efficacy and Safety of Ribociclib With Letrozole in US Patients Enrolled in the MONALEESA-2 Study

BACKGROUND

In the Mammary Oncology Assessment of LEE011's (Ribociclib's) Efficacy and Safety (MONALEESA-2) study, combination treatment with the selective inhibitor of cyclin-dependent kinases 4/6 ribociclib with letrozole significantly improved progression-free survival (PFS) versus letrozole alone in postmenopausal women with hormone receptor-positive HR⁺/HER2^- advanced breast cancer (ABC). Herein we present results from the subset of US patients enrolled in MONALEESA-2.

PATIENTS AND METHODS

Postmenopausal women with HR⁺/HER2^- ABC without previous treatment for advanced disease were randomized (1:1) to ribociclib 600 mg/d (3 weeks on/1 week off) with letrozole 2.5 mg/d (continuous) or placebo with letrozole. The primary end point was locally assessed PFS.

RESULTS

Overall, 213 US patients were enrolled in MONALEESA-2 (ribociclib, n = 100; placebo, n = 113). Baseline characteristics were similar between treatment groups and consistent with the global population. With a median follow-up of 27 months, 38 (38%) and 29 (26%) patients in the ribociclib and placebo groups, respectively, had continued to receive treatment. Median PFS was 27.6 months with ribociclib and 15.0 months with placebo (hazard ratio, 0.53). The most common all-cause adverse events were neutropenia (ribociclib, 72.0% [n = 72]; placebo, 4.6% [n = 5]), nausea (ribociclib, 69.0% [n = 69]; placebo, 44.0% [n = 48]), and fatigue (ribociclib, 60.0% [n = 60]; placebo, 50.5% [n = 55]). Two patients (ribociclib, 2.0%; placebo, 0%) experienced febrile neutropenia.

CONCLUSION

In the US subset of MONALEESA-2, ribociclib with letrozole showed superior efficacy versus letrozole alone. These findings are consistent with the global population and support first-line use of ribociclib with letrozole in patients with HR⁺/HER2^- ABC.

Treatment of advanced HR+/HER2- breast cancer with new targeted agents in combination with endocrine therapy: a review of efficacy and tolerability based on available randomized trials on everolimus, ribociclib, palbociclib and abemaciclib

INTRODUCTION

Recently, new targeted agents have been developed, which can prolong the effect of endocrine treatment (ET) by targeting resistance pathways in HR+/HER2- advanced breast cancer. This review examines available studies of everolimus, an mTOR inhibitor, and the CDK 4/6 inhibitors ribociclib, palbociclib and abemaciclib in terms of efficacy, tolerability and safety.

MATERIAL AND METHODS

A systematic literature search was performed in Pubmed. Evaluation of the quality of the identified studies was based on selected elements from the GRADE guidelines.

RESULTS

The literature search yielded eight randomized trials that all presented a significant increase in the progression free survival (PFS)/time to progression (TTP) for the targeted agents plus ET vs ET only. The improvement was evident as first-line therapy with an increase in PFS of 10-11 months when adding a CDK4/6 inhibitor to ET, as well as in patients previously treated for metastatic disease, with an increase of 5-6 months. The common adverse events (AEs) of the CDK 4/6 inhibitors were due to myelosuppression. In addition, abemaciclib was associated with liver toxicity and diarrhea, and ribociclib with liver toxicity and QTcF prolongation. The most common grade 3/4 AE of everolimus was stomatitis. The majority (five) of the trials had no serious limitations, and thus the quality of evidence was high.

DISCUSSION

The new targeted agents are all associated with an improvement of the PFS with an acceptable tolerability, and they should be offered to women with advanced HR+/HER2- breast cancer both as first-line therapy as well as among patients previously treated in metastatic regimens. However, further data regarding the impact on overall survival are required to evaluate the full benefit for patients. Price and differences in AEs could become substantial arguments for the choice of therapy for the individual patient.