Trastuzumab plus anastrozole versus anastrozole alone for the treatment of postmenopausal women with human epidermal growth factor receptor 2-positive, hormone receptor-positive metastatic breast cancer: results from the randomized phase III TAnDEM study

Development and clinical application of anti-HER2 monoclonal and bispecific antibodies for cancer treatment

HER2-targeted immunotherapy consists of monoclonal antibodies (e.g. trastuzumab, pertuzumab), bispecific antibodies (e.g. MM-111, ertumaxomab) and activated T cells armed with anti-HER2 bispecific antibody (HER2Bi-aATC). Trastuzumab is a classic drug for the treatment of HER2 positive metastatic breast cancer. The combined application of pertuzumab, trastuzumab and paclitaxel has been suggested as a standard therapy for HER2 positive advanced breast cancer. The resistance to anti-HER2 antibody has resulted in disease progression. HER2-directed bispecific antibody may be a promising therapeutic approach for these patients. Ertumaxomab enhanced the interaction of immune effector cells and tumor cells. MM-111 simultaneously binds to HER2 and HER3 and blocks downstream signaling. Besides, HER2Bi-aATC is also an alternative therapeutic approach for HER2 positive cancers. In this review, we summarized the recent advancement of HER2-targeted monoclonal antibodies (trastuzumab, pertuzumab and T-DM1) and bispecific antibodies (MM-111, ertumaxomab and HER2Bi-aATC), especially focus on clinical trial results.

Efficacy of fulvestrant in the treatment of postmenopausal women with endocrine-resistant advanced breast cancer in routine clinical practice

INTRODUCTION

This study aimed to describe the efficacy of fulvestrant 500 mg in postmenopausal women with estrogen receptor (ER)-positive advanced/metastatic breast cancer who had disease progression after receiving anti-estrogen therapy in clinical practice, getting real-world data.

MATERIALS AND METHODS

Multicenter, retrospective, observational study conducted in Spain. Postmenopausal women with locally advanced/metastatic ER-positive breast cancer who received treatment with fulvestrant 500 mg after progression with a previous anti-estrogen therapy were eligible. The primary endpoint was progression-free survival (PFS); secondary endpoints were overall survival (OS), clinical benefit rate (CBR), duration of clinical benefit (DoCB), and safety profile.

RESULTS

A total of 263 women were evaluated (median age, 65.8 years). At a median follow-up of 21.5 months, median PFS and OS were 10.6 and 43.2 months, respectively. PFS according to 1st, 2nd, 3rd, and ≥ 4th lines were 11.5, 10.6, 9.9, and 8.5 months, respectively (p = 0.0245). PFS in patients with visceral involvement was 10 months vs 10.6 months in patients without visceral involvement (p = 0.6604), 9.6 months in patients with high Ki67 vs 10 months in patients with low Ki67 (p = 0.7224), and 10.2 months in HER2+ patients vs 10.3 months in HER2- patients (p = 0.6809). The CBR was 56.5% and the DoCB was 18.4 months. The most frequently adverse events were injection site pain (10.3%) and musculoskeletal disorders (7.6%).

CONCLUSIONS

Fulvestrant 500 mg administered in clinical practice was shown to be effective (PFS, 10.6 months; CBR, 56.5%) and well tolerated, in accordance with previous trials.

Pharmacologic measures in the prevention of left ventricular dysfunction associated with molecular-targeted therapies in the treatment of cancer patients

INTRODUCTION

Left ventricular dysfunction (LVD) is an infrequent but significant side effect of certain molecular-targeted cancer therapies and may lead to treatment modification and impact on disease prognosis. There may be a role for beta blockers (BB), angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) in the prevention of LVD. Areas covered: There are multiple definitions for LVD based on clinical and/or imaging features. Molecular-targeted therapies cause reversible LVD. Therapies with well-reported LVD are inhibitors of human epidermal growth factor 2 (HER2), angiogenesis, Abelson murine leukemia viral oncogene homolog (ABL) and the proteasome. BB, ACEI and ARB seem to have a role in the prevention of LVD associated with anthracyclines. Few trials have investigated the role of BB, ACEI and ARB as primary prevention of LVD in molecular-targeted therapies. Their results are not conclusive but a beneficial role cannot be excluded. Expert opinion: Because of inconclusive data, future interventional studies should not include all treated patients with molecular-targeted therapy, but focus on patients at risk for developing LVD. Another option is to study patients who show early signs of LVD to prevent progression to overt heart failure.

Advances in the management of HER2-positive early breast cancer

While trastuzumab is firmly established as the cornerstone of therapy for both early and advanced breast cancer expressing human epidermal growth factor receptor 2 (HER2), many patients either do not respond to trastuzumab treatment or progress following therapy. Improved understanding of breast cancer biology, particularly the complex signaling interactions managed by the HER family of receptors, have resulted in development of several novel HER2-directed therapies and combinations. This article will review the novel approaches to HER2 targeting that have been developed in recent years, with particular focus on results from these approaches in early breast cancer, and will discuss strategies to improve the tolerability of HER2-directed therapies, including prevention of cardiac toxicity and diarrhea.

Impact of Her-2 Overexpression on Survival of Patients with Metastatic Breast Cancer

Introduction: Breast cancer is a complex and heterogeneous disease which is increasingly important as a public health problem. In Brazil, 57,960 new cases have been estimated to be the burden in 2016 and 2017. Despite advances in early diagnosis and therapy, approximately 20-30% of patients, even with early stage lesions, will develop distant metastatic disease. Tumors with similar clinical and pathological presentations may have differing behavior, so it is important to understand specific biological characteristics. Objective: To investigate tumor markers of primary tumors featuring pleural metastasis to identify organ-specific characteristics of metastatic breast cancer. Methods: In a historical cohort study, immunohistochemistry was performed on cell blocks of neoplastic pleural effusions and results were compared with clinicopathological data. Results: The median survival time with Her-2 overexpression in malignant pleural effusions was 2.2 months, whereas cases without overexpression survived, on average, for seven months (p = 0.02). Conclusions: We emphasize that metastases may behave independently of primary tumors, but the present results indicate that therapeutic agents targeting Her-2 overexpression could increase survival in metastatic breast cancer cases.

Impact of clinicopathological characteristics on the efficacy of neoadjuvant therapy in patients with human epidermal growth factor receptor-2-positive breast cancer

Neoadjuvant therapy has become increasingly common in human epidermal growth factor receptor-2 (HER2)-positive breast cancer. In this study, we examined the impact of different clinicopathological characteristics on pathological complete response (pCR) in patients treated with anti-HER2 agents. The PubMed and Embase databases were searched from inception through April 2017 to identify studies that met pre-specified criteria. The odds ratios (ORs) and 95% confidence intervals (CIs) were extracted directly or were calculated with other available information. Eleven randomized controlled trials (RCTs) that involved 3,269 HER2-positive women were included in this meta-analysis. Patients with hormone receptor (HR)-negative breast cancer benefited more from anti-HER2 therapy than did patients with HR-positive tumours (OR, 2.25; 95% CI, 1.93-2.62). Furthermore, this improvement in pCR was independent of anti-HER2 agents, phase, combined chemotherapy, neoadjuvant duration, year the trials started and region where the trials were conducted. Patients with small tumours achieved greater benefits than patients with large tumours (OR, 1.25; 95% CI, 1.00-1.55). Age did not predict an additional benefit from anti-HER2 neoadjuvant treatment (OR, 1.02; 95% CI, 0.73-1.45). The impact of nodal status on pCR was dependent on the anti-HER2 agents. In conclusion, for HER2-targeted neoadjuvant treatment in breast cancer, greater benefits were achieved in patients with small HR-negative tumours compared with patients with large HR-positive tumours. These results may improve drug development and treatment strategies, economic analyses and the design and interpretation of clinical trials.

Identification of the S100 fused-type protein hornerin as a regulator of tumor vascularity

Sustained angiogenesis is essential for the development of solid tumors and metastatic disease. Disruption of signaling pathways that govern tumor vascularity provide a potential avenue to thwart cancer progression. Through phage display-based functional proteomics, immunohistochemical analysis of human pancreatic ductal carcinoma (PDAC) specimens, and in vitro validation, we reveal that hornerin, an S100 fused-type protein, is highly expressed on pancreatic tumor endothelium in a vascular endothelial growth factor (VEGF)-independent manner. Murine-specific hornerin knockdown in PDAC xenografts results in tumor vessels with decreased radii and tortuosity. Hornerin knockdown tumors have significantly reduced leakiness, increased oxygenation, and greater apoptosis. Additionally, these tumors show a significant reduction in growth, a response that is further heightened when therapeutic inhibition of VEGF receptor 2 (VEGFR2) is utilized in combination with hornerin knockdown. These results indicate that hornerin is highly expressed in pancreatic tumor endothelium and alters tumor vessel parameters through a VEGF-independent mechanism.Angiogenesis is essential for solid tumor progression. Here, the authors interrogate the proteome of pancreatic cancer endothelium via phage display and identify hornerin as a critical protein whose expression is essential to maintain the pancreatic cancer vasculature through a VEGF-independent mechanism.

Therapeutic Implications of the Molecular and Immune Landscape of Triple-Negative Breast Cancer

Treatment and management of breast cancer imposes a heavy burden on public health care, and incidence rates continue to increase. Breast cancer is the most common female neoplasia and primary cause of death among women worldwide. The recognition of breast cancer as a complex and heterogeneous disease, comprising different molecular entities, was a landmark in our understanding of this malignancy. Valuing the impact of the molecular characteristics on tumor behavior enabled a better assessment of a patient's prognosis and increased the predictive power to therapeutic response and clinical outcome. Molecular heterogeneity is also prominent in the triple-negative breast cancer subtype, and is reflected by the distinct prognostic and patient's sensitivity to treatment, being chemotherapy the only systemic treatment currently available. From a therapeutic perspective, gene expression profiling of triple-negative tumors has notably contributed to the exploration of new druggable targets and brought to light the need to align these patients to the various therapies according to their triple-negative subtype. Additionally, the higher amount of tumor infiltrating lymphocytes, and the prevalence of an increased expression of PD-1 receptor and its ligand, PD-L1, in triple-negative tumors, created a new treatment opportunity with immune checkpoint inhibitors. This manuscript addresses the current knowledge on the molecular and immune profiles of breast cancer, and its impact on the development of targeted therapies, with a particular emphasis on the triple-negative subtype.

Foreword

Delivering multifaceted, quality care to women living with metastatic breast cancer (MBC) demands professional competence and an advanced level of practice. The breast cancer nursing community is evolving to meet this need as more nurses are appointed specifically for the advanced disease setting, while nurses who previously worked only in early stage disease are now delivering care across the disease trajectory, fulfilling a 'diagnosis to death' nursing model. The MBC nursing community, linked by UK charity Breast Cancer Care and the Roche Nursing Matters programme, offers forums for learning, and provides ongoing support to this group of nurses. This supplement has been commissioned by Roche Products Ltd to continue supporting nurses who treat patients with MBC by sharing learning and best practice, with a view to encouraging innovation in service delivery.

Improving patient care: expert nursing and service development

Early access to a clinical nurse specialist will ensure that patients receive the interventions and support they need. Optimum outcomes will be achieved if specialists work in collaboration with a wider team.

Introduction

Metastatic breast cancer (MBC), also known as secondary breast cancer (SBC), occurs when cells from the primary breast tumour metastasise from the breast to other parts of the body via the blood or lymphatic systems. The disease may range from limited bone metastases to widespread and life-threatening metastases in visceral organs such as the liver, lung and brain (National Institute for Health and Care Excellence (NICE), 2009; 2014). MBC is incurable, and the primary goal of treatment is to extend life and palliate symptoms, while preserving quality of life (NICE, 2009; 2014).

Defining what matters most to patients

Advanced communication skills are needed to identify patients' needs and provide the psychological and social support they require. Meanwhile, early access to palliative care will improve symptom control.

Incidence, Diagnosis, and Treatment of Cardiac Toxicity from Trastuzumab in Patients with Breast Cancer

PURPOSE OF REVIEW

Treatment with trastuzumab is a cornerstone of human epidermal growth factor receptor 2 (HER2)-overexpressing breast cancer treatment, but carries an unfortunate risk of toxicity to the cardiovascular system. Here we review recent findings on trastuzumab-associated cardiotoxicity, focusing on its incidence, diagnosis, and treatment.

RECENT FINDINGS

Screening with multigated acquisition scan (MUGA) or echocardiogram (ECHO) is recommended to assess cardiac function prior to and during trastuzumab therapy. Because trastuzumab-induced cardiotoxicity is typically reversible, cessation of trastuzumab and/or administration of first line heart failure agents effectively restores cardiac function in most cases. Severe trastuzumab-induced cardiotoxicity is rare enough that the risk-benefit ratio still weighs in favor of its use in the vast majority of patients with HER2+ breast cancer.

SUMMARY

An improved understanding of the pathophysiology underlying trastuzumab-induced cardiotoxicity and the identification of patients at highest risk will allow us to continue to safely administer trastuzumab in patients with breast cancer.

Treatment for the endocrine resistant breast cancer: Current options and future perspectives

Endocrine resistance remains a challenge and an unmet need for managing hormone receptor-positive breast cancer. The mechanisms of endocrine resistance are multifaceted and are likely to evolve over time following various single or combination therapies. The purpose of this review article is to provide general understanding of molecular basis of endocrine resistance of breast cancer and to offer comprehensive review on current treatment options and potential new treatment strategies for endocrine resistant breast cancers. Last but not the least, we discuss current challenges and future directions for management of endocrine resistant breast cancers.

Incidence and risk of cardiotoxicity in cancer patients treated with targeted therapies

BACKGROUND

Cardiotoxicityis a serious side effect of molecularly targeted agents. The purpose of this study was to evaluate the incidence and Relative Risk (RR) of developing all-grade and high-grade cardiotoxicity in patients with solid tumors receiving targeted agents through a revised meta-analysis of available clinical trials.

METHODS

The scientific literature regarding cardiotoxicity was extensively analyzed using MEDLINE, PubMed, Embase and Cochrane Central Register of Controlled Trials (CENTRAL). Eligible studies were selected according to PRISMA statement. Summary incidence, RR, and 95% CIs were calculated using random-effects or fixed-effects models based on the heterogeneity of selected studies.

RESULTS

Our search yielded a total of 4998 clinical studies; of them, 31 trials were finally considered for this meta-analysis. A total of 28,538 patients were included; 7995 of these patients had breast cancer (28%), 6151 (22%) prostate cancer and 14,392 (50%) were treated for other malignancies. The highest RR of high-grade events was observed with Vandetanib (RR=7.71, 95% CI 1.04-56.99), followed by Ramucirumab (RR=5.0) and Aflibercept (RR=4.1). Grouping by drug category, the highest incidence of high-grade cardiotoxicity was shown by anti-VEGFR-TKIs (RR 5.62, 95% CI 1.49-21.24) and anti-VEGF mAbs/VEGF-trap (RR 1.82, 95% CI 1.24-2.69). Grouping by tumor type, the highest incidence of cardiotoxicity was observed in thyroid cancer (8%), followed by gastric cancer (4%).

CONCLUSIONS

Treatment with targeted agents in cancer patients is correlated with a significant increase in the risk of cardiotoxicity. Frequent clinical monitoring should be emphasized when using these and newer biological agents.

Proteasome inhibitors prevent bi-directional HER2/estrogen-receptor cross-talk leading to cell death in endocrine and lapatinib-resistant HER2+/ER+ breast cancer cells

Amplification and/or overexpression of the human epidermal growth factor 2 (HER2) oncogene occurs in about 13–15% of invasive breast cancer and triggers breast cancer cell proliferation, survival and metastatic progression. Around half of all breast cancers with HER2 overexpression co-express hormone receptors (HR) such as those for estrogen and progesterone. Aberrant signaling through HER2 and other members of the HER-family mediates endocrine-resistance in estrogen receptor alpha (ERα) positive breast cancer. On the other hand, ERα co-expression has been shown to attenuate the efficiency of anti-HER2 therapies. These findings indicate that HER2 and ERα synergize to escape from both anti-ERα and anti-HER2-targeted therapies. Rationally designed clinical trials that combine endocrine therapy with anti-HER2 agents to interfere with HER2/ERα cross-talk have been conducted. However, the outcome of these trials suggests that novel therapeutic approaches are needed to further improve inhibition of HER2 and other HER-family members in conjunction with a more efficient ERα blockade. Here, we demonstrate that carfilzomib and bortezomib stabilize the HER2-specific protein tyrosine phosphatase BDP1 leading to decreased HER2 autophosphorylation, reduced HER2 activity and subsequently attenuated activation of the PI3K/Akt-pathway, together with blockade of ERα expression. We further observed that proteasome inhibitors (PIs) reverse autophosphorylation and thereby inhibit the activity of constitutively active mutant HER2. We also demonstrate that PIs cause cell death in lapatinib and endocrine-resistant HER2+/ER+ breast cancer cells. These findings suggest that PIs might have the potential to improve the management of HER2+/ER+ breast cancer patients by efficiently disrupting the bi-directional HER2/ERα cross-talk.

Breast cancer treatment-induced cardiotoxicity

INTRODUCTION

Breast cancer is the most frequent cancer affecting women worldwide. In every setting, the majority of women are treated with an evergrowing arsenal of therapeutic agents that have greatly improved their outcomes. However, these therapies can also be associated with significant adverse events. Areas covered: This review aims to thoroughly describe the current state of the evidence regarding the potential cardiotoxicity of agents commonly used in the treatment of breast cancer. These include chemotherapeutic agents, anti-HER2 therapies and CDK4/6 and mTOR inhibitors. Furthermore, issues related to the risk stratification and monitoring tools are explored. Expert opinion: Anthracycline- and trastuzumab-related cardiac toxicities have been extensively studied. Substantial evidence is now available concerning additional anti-HER2 agents such as pertuzumab, T-DM1 and tyrosine kinase inhibitors; overall, the cardiotoxicity profile is reassuring. Cardiac events due to endocrine therapy are mostly ischemic and, in the context of prolonged therapy, need specific attention. Novel agents implicated in the treatment of hormone receptor-positive disease are potentially arrhythmogenic and the exact risk will need to be further refined. As for today, assessment of baseline risk factors prior to treatment initiation and cardiac imaging before and during treatment remains the optimal way to prevent cardiac dysfunction. Cardioprotective therapy in primary prevention is still a matter of debate.

Evolution of anti-HER2 therapies for cancer treatment

The development of HER2-directed monoclonal antibodies and tyrosine kinase inhibitors have provided benefits to cancer patients, as well as produced many insights into the biology of the ErbB receptor family. Current therapies based on ErbB family members have resulted in improved overall survival with associated improvements in quality of life for the cancer patients that respond to treatment. Compared to monotherapy using either two antibodies to block the HER2 receptor blockade or combinatorial approaches with HER2 antibodies and standard therapies has provided additional benefits. Despite the therapeutic success of existing HER2 therapies, personalising treatment and overcoming resistance to these therapies remains a significant challenge. The heterogeneous intra-tumoural HER2 expression and lack of fully predictive and prognostic biomarkers remain significant barriers to improving the use of HER2 antibodies. Imaging modalities using radiolabelled pertuzumab and trastuzumab allow quantitative assessment of intra-tumoural HER2 expression, HER2 antibody saturation and the success of different drug delivery systems to be assessed. Molecular imaging with HER2 antibodies has the potential to be a non-invasive, predictive and prognostic technique capable of influencing therapeutic decisions, predicting response and failure of treatments as well as providing insights into receptor recycling and signalling. Similarly, conjugating HER2 antibodies with novel toxic payloads or combining HER2 antibodies with cellular immunotherapy provide exciting new opportunities for the management of tumours overexpressing HER2. Future research will lead to higher therapeutic responses, lower toxicities and providing insight into the mechanisms of resistance to HER2-targeted treatments.

Neratinib Efficacy and Circulating Tumor DNA Detection of HER2 Mutations in HER2 Nonamplified Metastatic Breast Cancer

Purpose: Based on promising preclinical data, we conducted a single-arm phase II trial to assess the clinical benefit rate (CBR) of neratinib, defined as complete/partial response (CR/PR) or stable disease (SD) ≥24 weeks, in HER2^mut nonamplified metastatic breast cancer (MBC). Secondary endpoints included progression-free survival (PFS), toxicity, and circulating tumor DNA (ctDNA) HER2^mut detection.Experimental Design: Tumor tissue positive for HER2^mut was required for eligibility. Neratinib was administered 240 mg daily with prophylactic loperamide. ctDNA sequencing was performed retrospectively for 54 patients (14 positive and 40 negative for tumor HER2^mut).Results: Nine of 381 tumors (2.4%) sequenced centrally harbored HER2^mut (lobular 7.8% vs. ductal 1.6%; P = 0.026). Thirteen additional HER2^mut cases were identified locally. Twenty-one of these 22 HER2^mut cases were estrogen receptor positive. Sixteen patients [median age 58 (31-74) years and three (2-10) prior metastatic regimens] received neratinib. The CBR was 31% [90% confidence interval (CI), 13%-55%], including one CR, one PR, and three SD ≥24 weeks. Median PFS was 16 (90% CI, 8-31) weeks. Diarrhea (grade 2, 44%; grade 3, 25%) was the most common adverse event. Baseline ctDNA sequencing identified the same HER2^mut in 11 of 14 tumor-positive cases (sensitivity, 79%; 90% CI, 53%-94%) and correctly assigned 32 of 32 informative negative cases (specificity, 100%; 90% CI, 91%-100%). In addition, ctDNA HER2^mut variant allele frequency decreased in nine of 11 paired samples at week 4, followed by an increase upon progression.Conclusions: Neratinib is active in HER2^mut, nonamplified MBC. ctDNA sequencing offers a noninvasive strategy to identify patients with HER2^mut cancers for clinical trial participation. Clin Cancer Res; 23(19); 5687-95. ©2017 AACR.

Release of HER2 repression of trefoil factor 3 (TFF3) expression mediates trastuzumab resistance in HER2+/ER+ mammary carcinoma

HER2+/ER+ breast cancer, a subset of the luminal B subtype, makes up approximately 10% of all breast cancers. The bidirectional crosstalk between HER2 and estrogen receptor (ER) in HER2+/ER+ breast cancer contributes to resistance towards both anti-estrogens and HER2-targeted therapies. TFF3 promotes breast cancer progression and has been implicated in anti-estrogen resistance in breast cancer. Herein, we investigated the cross-regulation between HER2 and estrogen-responsive TFF3, and the role of TFF3 in mediating trastuzumab resistance in HER2+/ER+ breast cancer. TFF3 expression was decreased by HER2 activation, and increased by inhibition of HER2 with trastuzumab in HER2+/ER+ breast cancer cells, partially in an ERα-independent manner. In contrast, the forced expression of TFF3 activated the entire HER family of receptor tyrosine kinases (HER1-4). Hence, HER2 negatively regulates its own signalling through the transcriptional repression of TFF3, while trastuzumab inhibition of HER2 results in increased TFF3 expression to compensate for the loss of HER2 signalling. In HER2+/ER+ breast cancer cells with acquired trastuzumab resistance, TFF3 expression was markedly upregulated and associated with a corresponding decrease in HER signalling. siRNA mediated depletion or small molecule inhibition of TFF3 decreased the survival and growth advantage of the trastuzumab resistant cells without re-sensitization to trastuzumab. Furthermore, TFF3 inhibition abrogated the enhanced cancer stem cell-like behaviour in trastuzumab resistant HER2+/ER+ breast cancer cells. Collectively, TFF3 may function as a potential biomarker and therapeutic target in trastuzumab resistant HER2+/ER+ breast cancer.

Long-term remission of hormone receptor-positive/HER2-positive metastatic breast cancer due to combined treatment with everolimus/trastuzumab/exemestane: A case report

The present case report describes a postmenopausal patient with hormone receptor (HR)⁺/human epidermal growth factor receptor 2 (HER2)⁺ metastatic breast cancer, who experienced progression of disease in bilateral lungs, lymph nodes and the liver under previous endocrine therapy and trastuzumab. Following the failure of two lines of endocrine-based treatment, the patient was administered the combined treatment of everolimus, trastuzumab and exemestane following surgical resection of the liver metastasis. A durable partial remission was achieved, which has continued for >27 months. This prominent clinical outcome in this patient demonstrates that the combined administration of endocrine therapy, trastuzumab and everolimus is clinically effective, and may induce long-term remission in patients with HR⁺/HER2⁺ metastatic breast cancer.

Direct estrogen receptor (ER) / HER family crosstalk mediating sensitivity to lumretuzumab and pertuzumab in ER+ breast cancer

Bidirectional cross talk between members of the human epidermal growth factor family of receptors (HER) and the estrogen receptor (ER) is believed to underlie resistance mechanisms that develop in response to treatment with anti-HER agents and endocrine therapy. We investigated the interaction between HER2, HER3 and the ER in vitro using human embryonic kidney cells transfected with human HER2, HER3, and ERα. We also investigated the additive efficacy of combination regimens consisting of anti-HER3 (lumretuzumab), anti-HER2 (pertuzumab), and endocrine (fulvestrant) therapy in vivo. Our data show that both HER2 and HER3 can directly complex with the ER and can mediate phosphorylation of the ER. Phosphorylation of the ER was only observed in cells that expressed both HER2 and ERα or in heregulin-stimulated cells that expressed both HER3 and ERα. Using a mouse xenograft model of ER+/HER2-low (HER2 immunohistochemistry 1+ or 2+ without gene amplification) human breast cancer we show that the combination of lumretuzumab and pertuzumab is highly efficacious and induces long-lasting tumor regression in vivo and adding endocrine therapy (fulvestrant) to this combination further improved efficacy. In addition, a prolonged clinical response was observed with the combination of lumretuzumab and pertuzumab in a patient with ER+/HER2-low breast cancer who had failed endocrine therapy. These preclinical data confirm that direct cross talk exists between HER2/HER3 and ER which may explain the resistance mechanisms to endocrine therapy and monoclonal antibodies that target HER2 and HER3. Our data also indicate that the triplet of anti-HER2, anti-HER3, and endocrine therapy might be an efficacious combination for treating patients with ER+/HER2-low breast cancer, which is an area of significant unmet medical need.

Dual inhibition of IGF1R and ER enhances response to trastuzumab in HER2 positive breast cancer cells

Although HER2 targeted therapies have improved prognosis for HER2 positive breast cancer, HER2 positive cancers which co-express ER have poorer response rates to standard HER2 targeted therapies, combined with chemotherapy, than HER2 positive/ER negative breast cancer. Administration of hormone therapy concurrently with chemotherapy and HER2 targeted therapy is generally not recommended. Using publically available gene expression datasets we found that high expression of IGF1R is associated with shorter disease-free survival in patients whose tumors are ER positive and HER2 positive. IGF1R is frequently expressed in HER2 positive breast cancer and there is significant evidence for crosstalk between IGF1R and both HER2 and ER. Therefore, we evaluated the therapeutic potential of targeting ER and IGF1R in cell line models of HER2/ER/IGF1R positive breast cancer, using tamoxifen and two IGF1R targeted tyrosine kinase inhibitors (NVP-AEW541 and BMS-536924). Dual inhibition of ER and IGF1R enhanced growth inhibition in the four HER2 positive cell lines tested and caused an increase in cell cycle arrest in G1 in BT474 cells. In addition, combined treatment with trastuzumab, tamoxifen and either of the IGF1R TKIs enhanced response compared to dual targeting strategies in three of the four HER2 positive breast cancer cell lines tested. Furthermore, in a cell line model of trastuzumab-resistant HER2 positive breast cancer (BT474/Tr), tamoxifen combined with an IGF1R TKI produced a similar enhanced response as observed in the parental BT474 cells suggesting that this combination may overcome acquired trastuzumab resistance in this model. Combining ER and IGF1R targeting with HER2 targeted therapies may be an alternative to HER2 targeted therapy and chemotherapy for patients with HER2/ER/IGF1R positive breast cancer.

Impact of hormone receptor status and distant recurrence-free interval on survival benefits from trastuzumab in HER2-positive metastatic breast cancer

We sought to investigate the impact of hormone receptor (HR) status and distant recurrence-free interval (DRFI) on the degree of overall survival (OS) benefit from palliative trastuzumab-containing treatment in HER2-positive metastatic breast cancer (MBC). Here, we retrospectively identified 588 eligible HER2-positive patients with postoperative distant recurrence. DRFI of HR+HER2+ MBC patients (median: 30.7 months, IQR: 18.5-45.9, P < 0.001) was significant longer compared with HR-HER2+ patients. Patients were categorized into four subgroups based on HR status and palliative trastuzumab (trast+) received. The most superior outcome was observed in the HR+HER2+trast+ subgroup, with a median OS of 48.3 months. Moreover, DRFI > 24 months is an independent favourable prognostic factor for both HR-HER2+ patients (Hazard Ratio (HzR) = 0.55, 95% CI: 0.39-0.76, P < 0.001) and HR+HER2+ patients (HzR = 0.45, 95% CI: 0.32-0.64, P  <  0.001). Upon further analysis of the interaction between trastuzumab and DRFI, the degree of trastuzumab benefits in HR-HER2+ MBC patients remained basically unchanged regardless of DRFI length. Unlikely, the degree in HR+HER2+ MBC patients decreased gradually along with DRFI extending, indicating that trastuzumab failed to translate into an OS benefit for late recurrent (DRFI > 5years) HR+HER2+ MBC patients.

MED1 may explain the interaction between receptor tyrosine kinases and ERα66 in the complicated network of Tamoxifen resistance

According to the American Society of Clinical Oncology or ASCO's clinical practice guidelines, administration of Tamoxifen for hormone receptor positive patients improved outcomes. However, many studies have been conducted in this issue, with the rise of Tamoxifen resistance in recent decades. There are many alternative growth cascades that are activated in Tamoxifen resistant cells. The most common and well characterized components of such a resistant network are receptor tyrosine kinases, or RTKs, which can influence many other cellular processes. The interactions between estrogen dependent and independent pathways further complicate the networking. MED1, as a member of a mediator complex, which is activated by RTK growth pathways, plays role in co-activating ERα66 to transcribe genes and enhance cellular proliferation. Herein, we will discuss MED1, a novel biomarker which can explain how RTKs interact with ERα66 which results in Tamoxifen resistance.

Are life-saving anticancer drugs reaching all patients? Patterns and discrepancies of trastuzumab use in the European Union and the USA

Background

The development of trastuzumab is considered to be one of the greatest improvements in breast cancer treatment in recent years. This study aims to evaluate changes in the uptake of trastuzumab over the last 12 years and to determine whether its use is proportional to patient needs in the European Union and the USA.

Methods

Using national registry data, the number of new cases of HER2-positive breast cancer patients per year was estimated. The number of likely trastuzumab treatments per year was estimated using trastuzumab procurement data for each country.

Results

Western Europe and the USA show increasing procurement level of trastuzumab over the years studied, reaching proportional of use of trastuzumab few years after its marketing authorization in the early 2000’s. After the approval in the adjuvant setting, in the year 2006, it was observed underuse of trastuzumab given the increase of the number of patients in need of treatment. Proportional use was shortly met after a couple of years. Few countries in Eastern Europe acquired the needed quantity of trastuzumab, with procurement levels starting to increase only after approval in the adjuvant setting in 2006.

Conclusion

Significant differences in trastuzumab procurement are observed between Western Europe, the USA and Eastern Europe, with the latter geographic region acquiring insufficient amounts of the drug required to treat all patients in need.

Novel Strategies to Improve the Endocrine Therapy of Breast Cancer

Endocrine therapy (ET) constitutes the usual first-line of therapy for patients in the treatment of metastatic hormone receptor-positive breast cancer. Unfortunately, not all patients respond to first-line endocrine treatment due to intrinsic resistance, while others may initially respond but eventually progress with secondary acquired resistance leading to disease progression. Mechanisms of resistance to anti-estrogen therapy include, loss of expression for estrogen or progesterone receptor, upregulation of epidermal receptor growth factor 2, increased receptor tyrosine kinase signaling, leading to activation of various intracellular pathways that are involved in signal transduction such as PI3K/AKT/mammalian target of rapamycin, and others. Growing understanding of the signal cascade of estrogen receptors and the signaling pathways that interact with estrogen receptors has revealed the complex role of these receptors in cell growth and proliferation, and on the mechanism in development of resistance. These insights have led to the development of targeted therapies that may prove to be effective options for the treatment of breast cancer and may overcome hormone therapy resistance. In this review we summarize some of the mechanisms of endocrine resistance, selected clinical trials of ET and targeted therapies, which might interfere with estrogen receptor pathways and might reduce or reverse resistance to traditional, sequential, single-agent ET.

Co-targeting the HER and IGF/insulin receptor axis in breast cancer, with triple targeting with endocrine therapy for hormone-sensitive disease

PURPOSE

Interactions between HER2, estrogen receptor (ER), and insulin-like growth factor I receptor (IGF1R) are implicated in resistance to monotherapies targeting these receptors. We have previously shown in pre-clinical studies synergistic anti-tumor effects for co-targeting each pairwise combination of HER2, IGF1R, and ER. Strikingly, synergy for HER2/IGF1R targeting occurred not only in a HER2+ model, but also in a HER2-normal model. The purpose of the current study was therefore to determine the generalizability of synergistic anti-tumor effects of co-targeting HER2/IGF1R, the anti-tumor activity of triple-targeting HER2/IGF1R/ER in hormone-dependent cell lines, and the effect of using the multi-targeting drugs neratinib (pan-HER) and BMS-754807 (dual IGF1R/insulin receptor).

METHODS

Proliferation and apoptosis assays were performed in a large panel of cell lines representing varying receptor expression levels. Mechanistic effects were studied using phospho-protein immunoblotting. Analyses of drug interaction effects were performed using linear mixed-effects regression models.

RESULTS

Enhanced anti-proliferative effects of HER/IGF-insulin co-targeting were seen in most, though not all, cell lines, including HER2-normal lines. For ER+ lines, triple targeting with inclusion of anti-estrogen generally resulted in the greatest anti-tumor effects. Double or triple targeting generally resulted in marked increases in apoptosis in the sensitive lines. Mechanistic studies demonstrated that the synergy between drugs was correlated with maximal inhibition of Akt and ERK pathway signaling.

CONCLUSIONS

Dual HER/IGF-insulin targeting, and triple targeting with inclusion of anti-estrogen drugs, shows striking anti-tumor activity across breast cancer types, and drugs with broader receptor specificity may be more effective than single receptor selective drugs, particularly for ER- cells.

Increased life expectancy as a result of non-hormonal targeted therapies for HER2 or hormone receptor positive metastatic breast cancer: A systematic review and meta-analysis

This article aimed to assess the clinical effectiveness of non-hormonal targeted therapies (TTs) in terms of increase of median progression-free survival (PFS) and overall survival (OS) in receptor-positive metastatic breast cancer (MBC) patients by performing a systematic review and meta-analysis. We systematically searched relevant randomized controlled trials and extracted data about number of patients on targeted and comparator therapy, receptor status, line of treatment, median PFS and OS, p values, hazard ratios (HRs) and 95% confidence intervals (CI). Inverse variance was used to estimate pooled HRs, chi-square test for heterogeneity and Jadad scale for quality were applied. Thirty-eight studies (n=17,192 patients) were eligible for inclusion. TTs added 3.3months to the median PFS [0.7-9.6; HRs 0.74, 95% CI 0.71-0.77] of receptor-positive MBC patients and prolonged their median OS with 3.5months [0-4.7; HRs 0.90, 95% CI 0.82-0.98]. The highest increase in median PFS of 3.6months was found in HER2-/hormone receptor(HR)+ patients, while the highest increase in median OS of 7.2months was observed in HER2+/HRmixed status patients. First-line TTs were most effective in increasing the median PFS in the HR+/HER2- group with 2.0months, and in the HER2+/HRmixed group by adding 4.7months to the median OS. Second-line TTs were most effective for HER2-/HR+ patients by adding 2.6months to their PFS, and for HER2+/HRmixed patients by adding 3.1months to their median OS. Albeit small, the gain in months of median PFS and median OS was significant. Importantly, the results reported show large variation, and thus routinely applying a personalized approach seems warranted.

"Triple positive" early breast cancer: an observational multicenter retrospective analysis of outcome

We recently found that trastuzumab benefit may be lower in a small subset of early breast cancer (BC) patients (pts) with tumors expressing high levels of both hormonal receptors (HRs), i.e. triple positive (TP). To better investigate the role of HRs in HER2 positive BC, we retrospectively identified 872 TP BC pts treated with adjuvant chemotherapy alone (cohort A-366 pts), or plus trastuzumab (cohort B-506 pts). Relapse-free-survival (RFS) and breast-cancer-specific-survival (BCSS) were evaluated. Trastuzumab improved RFS and BCSS in all the subsets analyzed, but the effect on BCSS in tumors expressing both HRs in >30% of cells (TP30), and even on RFS in tumors with both HRs expressed in >50% of cells (TP50) was not significant. Distinct patterns of relapse were observed in TP50 and no-TP50 tumors, the former showing low and constant risk in the first 5 years, a late increase beyond 5 years and modest trastuzumab effect. Trastuzumab effect tended to disappear in pts whose tumors expressed ER in >50% of cells. Multivariate analysis of RFS confirmed a significant interaction between trastuzumab and ER expression, with benefit confined to pts whose tumors expressed ER in ≤50% of cells. Our data suggest that the pattern of relapse of TP tumors with high HRs is similar to that of "luminal", HER2 negative tumors, without clear benefit from adjuvant trastuzumab, which remains the standard treatment even in TP tumors. Confirmatory findings on the extent to which quantitative expression of HRs may impact clinical behavior of HER2 positive BC are warranted.

Improving Response to Hormone Therapy in Breast Cancer: New Targets, New Therapeutic Options

The majority of breast cancer expresses the estrogen and or progesterone receptors (ER and PR). In tumors without concomitant HER2 amplification, hormone therapy is a major treatment option for all disease stages. Resistance to hormonal therapy is associated with disease recurrence and progression. Recent studies have identified a number of resistance mechanisms leading to estrogen-independent growth of hormone receptor-positive (HR+) breast cancer as a result of genetic and epigenetic alterations, which could be exploited as novel therapeutic targets. These include acquired mutations in ER-alpha (ESR1) in response to endocrine deprivation; constitutive activation of cyclin-dependent kinases (CDK) 4 and 6; cross talk between ER and growth factor receptor signaling such as HER family members, fibroblast growth factor receptor (FGFR) pathways, intracellular growth, and survival signals PI3K/Akt/mTOR; and epigenetic modifications by histone deacetylase (HDAC) as well as interactions with tumor microenvironment and host immune response. Inhibitors of these pathways are being developed to improve efficacy of hormonal therapy for treatment of both metastatic and early-stage disease. Two agents are currently approved in the United States for the treatment of metastatic HR+ breast cancer, including the mTOR inhibitor everolimus and the CDK4/6 inhibitor palbociclib. Management of toxicity is a critical aspect of treatment; the primary toxicity of everolimus is stomatitis (treated with topical steroids) and of palbociclib is neutropenia (treated with dose reduction/delay). Many agents are in clinical trials, primarily in combination with hormone therapy; novel combinations are under active investigation.

Treatment with aromatase inhibitors stimulates the expression of epidermal growth factor receptor-1 and neuregulin 1 in ER positive/HER-2/neu non-amplified primary breast cancers

While estrogens have been shown to modulate EGFR/HER-1 and HER-2/neu expression in experimental systems, the effects of estrogen deprivation on expression levels of the HER-receptors and the neuregulin (NRG)1 ligand in breast cancers remain unknown. Here, we measured EGFR/HER-1-4 and NRG1 mRNA in ER positive tumors from 85 postmenopausal breast cancer patients before and after two weeks (n=64) and three months (n=85) of primary treatment with an aromatase inhibitor (AI). In tumors lacking HER-2/neu amplification, quantitative real-time PCR analyses revealed EGFR/HER-1 and NRG1 to vary significantly between the three time points (before therapy, after 2 weeks and after 3 months on treatment; P≤0.001 for both). Pair-wise comparison revealed a significant increase in EGFR/HER-1 already during the first two weeks of treatment (P=0.049) with a further increase for both EGFR/HER-1 and NRG1 after 3 months on treatment (P≤0.001 and P=0.001 for both comparing values at 3 months to values at baseline and 2 weeks respectively). No difference between tumors responding versus non-responders was recorded. Further, no significant change in any parameter was observed among HER-2/neu amplified tumors. Analyzing components of the HER-2/neu PI3K/Akt downstream pathway, the PIK3CA H1047R mutation was associated with treatment response (P=0.035); however no association between either AKT phosphorylation status or PIK3CA gene mutations and EGFR/HER-1 or NRG1 expression levels were observed. Our results indicate primary AI treatment to modulate expression of HER-family members and the growth factor NRG1 in HER-2/neu non-amplified breast cancers in vivo. Potential implications to long term sensitivity warrants further investigations.

Strategies and Progress of Endocrine Therapy for Patients with Metastatic Breast Cancer

Breast cancer is one of the most prevalent cancers and the leading causes of cancer mortality in women worldwide and in China. For hormone receptor-positive (HR+) breast cancer, accounting for approximately 60-80% of breast cancer, endocrine therapy (ET) is the primary treatment strategy. For patients with HR+ metastatic breast cancer (MBC), there are many endocrine-based treatment options that can improve long-term outcomes and optimize quality of life. With the emergence and availability of new and effective agents, the options for ET have expanded in the last two decades. Although hormone therapy has been a standard of care for many decades, treatment must be individualized based on tumor biology and extent of disease. For example, the patients with impending organ failure may be treated with induction chemotherapy to improve organ function, followed by ET. For the patients who develop metastatic disease while on adjuvant ET, particularly when associated with organ failure, or for those with low expression of hormone receptors or expression of HER2, chemotherapy again may be a preferred initial treatment. ET blocks estrogen-driven tumor growth through different mechanisms; however, HR+ MBC can be intrinsically resistant or may acquire resistance to the treatment. Several targeted agents have been approved to use in combination with ET to improve response and delay development of resistance.

Synergistic disruption of ERα/HER2 crosstalk by endoxifen and lapatinib in breast cancer cells

BACKGROUND

Despite decades of clinical success, tamoxifen therapy is complicated by inter-individual variability due to CYP450 polymorphism and resistance attributed to ERα/HER2 crosstalk. Direct administration of endoxifen shows promise in circumventing obligatory CYP450 bioactivation while maintaining efficacy. Separately, disruption of the crosstalk using probe antagonists against ERα (tamoxifen) and HER2 (e.g., lapatinib) has been explored clinically. However, the efficacy of this combination may be confounded by lapatinib, a potent inactivator of CYP3A4/5 which could negate the bioactivation of tamoxifen to the active metabolite endoxifen. Additionally, in a manner analogous to tamoxifen, endoxifen is similarly not immune to the development of ERα/HER2 crosstalk that could result in resistance. Simultaneous antagonism of ERα and HER2 using endoxifen and lapatinib could overcome these problems.

METHODS

Metabolism studies were performed in human liver microsomes to determine the extent of inhibition of tamoxifen bioactivation by lapatinib. Synergism of endoxifen and lapatinib was assessed using the combination index design in a panel of cell models exhibiting either a priori ERα/HER2 crosstalk (BT474) or acquired ERα/HER2 crosstalk (TAM-R and MCF-7/HER2).

RESULTS

Lapatinib inhibited tamoxifen bioactivation by up to 1.8-fold. Synergistic activity was uncovered for lapatinib and endoxifen against BT474, TAM-R and MCF-7/HER2 models of ERα/HER2 crosstalk. Western blot confirmed that endoxifen and lapatinib disrupted this crosstalk.

CONCLUSION

This forward-looking study extends the success of tamoxifen by exploring the effectiveness of combining the next-generation tamoxifen derivative, endoxifen with an anti-HER2 agent to combat ERα/HER2 crosstalk, and at the same time provides a solution to the predicted pharmacokinetic antagonism between lapatinib and tamoxifen.

Dendritic Cell Vaccination Enhances Immune Responses and Induces Regression of HER2pos DCIS Independent of Route: Results of Randomized Selection Design Trial

Purpose: Vaccination with HER2 peptide-pulsed DC1s stimulates a HER2-specific T-cell response. This randomized trial aimed to establish safety and evaluate immune and clinical responses to vaccination via intralesional (IL), intranodal (IN), or both intralesional and intranodal (ILN) injection.Experimental Design: Fifty-four HER2^pos patients [42 pure ductal carcinoma in situ (DCIS), 12 early invasive breast cancer (IBC)] were enrolled in a neoadjuvant HER2 peptide-pulsed DC1 vaccine trial. Patients were randomized to IL (n = 19), IN (n = 19), or ILN (n = 16) injection. Immune responses were measured in peripheral blood and sentinel lymph nodes by ELISPOT or in vitro sensitization assay. Pathologic response was assessed in resected surgical specimens.Results: Vaccination by all injection routes was well tolerated. There was no significant difference in immune response rates by vaccination route (IL 84.2% vs. IN 89.5% vs. ILN 66.7%; P = 0.30). The pathologic complete response (pCR) rate was higher in DCIS patients compared with IBC patients (28.6% vs. 8.3%). DCIS patients who achieved pCR (n = 12) and who did not achieve pCR (n = 30) had similar peripheral blood anti-HER2 immune responses. All patients who achieved pCR had an anti-HER2 CD4 immune response in the sentinel lymph node, and the quantified response was higher by response repertoire (P = 0.03) and cumulative response (P = 0.04).Conclusions: Anti-HER2 DC1 vaccination is a safe and immunogenic treatment to induce tumor-specific T-cell responses in HER2^pos patients; immune and clinical responses were similar independent of vaccination route. The immune response in the sentinel lymph nodes, rather than in the peripheral blood, may serve as an endpoint more reflective of antitumor activity. Clin Cancer Res; 23(12); 2961-71. ©2016 AACR.

Cotargeting of CYP-19 (aromatase) and emerging, pivotal signalling pathways in metastatic breast cancer

Aromatase inhibition is one of the cornerstones of modern endocrine therapy of oestrogen receptor-positive (ER+) metastatic breast cancer (MBC). The nonsteroidal aromatase inhibitors anastrozole and letrozole, as well as the steroidal aromatase inactivator exemestane, are the preferred drugs and established worldwide in all clinical phases of the disease. However, although many patients suffering from MBC experience an initial stabilisation of their metastatic burden, drug resistance and disease progression occur frequently, following in general only a few months on treatment. Extensive translational research during the past two decades has elucidated the major pathways contributing to endocrine resistance and paved the way for clinical studies investigating the efficacy of novel drug combinations involving aromatase inhibitors and emerging drugable targets like mTOR, PI3K and CDK4/6. The present review summarises the basic research that provided the rationale for new drug combinations involving aromatase inhibitors and the main findings of pivotal clinical trials that have already started to change our way to treat hormone-sensitive MBC. The challenging situation of oestrogen receptor-positive and human epidermal growth factor receptor 2-positive (HER2+) MBC is also shortly reviewed to underline the complexity of the clinical scenario in the heterogeneous subgroups of hormone receptor-positive breast cancer patients and the increasing need for personalised medicine. Finally, we summarise some of the promising findings made with the combination of aromatase inhibitors with other potent endocrine treatment options like fulvestrant, a selective oestrogen receptor downregulator.

Trastuzumab cardiotoxicity: from clinical trials to experimental studies

Epidermal growth factor receptor-2 (HER-2) is overexpressed in 20 to 25% of human breast cancers, which is associated with aggressive tumour growth and poor prognosis. Trastuzumab (Herceptin®) is a humanized monoclonal antibody directed against HER-2, the first highly selective form of therapy targeting HER-2 overexpressing tumours. Although initial trials indicated high efficacy and a favourable safety profile of the drug, the first large, randomized trial prompted a retrospective analysis of cardiac dysfunction in earlier trials utilizing trastuzumab. There has been ongoing debate on the cardiac safety of trastuzumab ever since, initiating numerous clinical and preclinical investigations to better understand the background of trastuzumab cardiotoxicity and evaluate its effects on patient morbidity. Here, we have given a comprehensive overview of our current knowledge on the cardiotoxicity of trastuzumab, primarily focusing on data from clinical trials and highlighting the main molecular mechanisms proposed.

LINKED ARTICLES

This article is part of a themed section on New Insights into Cardiotoxicity Caused by Chemotherapeutic Agents. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.21/issuetoc.

Bridging the gap between clinicians and systems biologists: from network biology to translational biomedical research

With the wealth of data accumulated from completely sequenced genomes and other high-throughput experiments, global studies of biological systems, by simultaneously investigating multiple biological entities (e.g. genes, transcripts, proteins), has become a routine. Network representation is frequently used to capture the presence of these molecules as well as their relationship. Network biology has been widely used in molecular biology and genetics, where several network properties have been shown to be functionally important. Here, we discuss how such methodology can be useful to translational biomedical research, where scientists traditionally focus on one or a small set of genes, diseases, and drug candidates at any one time. We first give an overview of network representation frequently used in biology: what nodes and edges represent, and review its application in preclinical research to date. Using cancer as an example, we review how network biology can facilitate system-wide approaches to identify targeted small molecule inhibitors. These types of inhibitors have the potential to be more specific, resulting in high efficacy treatments with less side effects, compared to the conventional treatments such as chemotherapy. Global analysis may provide better insight into the overall picture of human diseases, as well as identify previously overlooked problems, leading to rapid advances in medicine. From the clinicians’ point of view, it is necessary to bridge the gap between theoretical network biology and practical biomedical research, in order to improve the diagnosis, prevention, and treatment of the world’s major diseases.

Targeted Therapies in HER2-Overexpressing Metastatic Breast Cancer

Human epidermal growth factor receptor-2 (HER2) is amplified in 25-30% of breast cancers and is associated with aggressive disease and poorer survival. Multiple anti-HER2 targeted therapies have dramatically changed management and outcome of this subgroup, both in adjuvant and metastatic settings. Despite the improvement of survival thanks to trastuzumab, unclear mechanisms of resistance occur, which has led to the development of new anti-HER2 therapies such as lapatinib, pertuzumab, and trastuzumab emtansine (T-DM1). The optimal sequence of the available drugs is still not well established. All this progress raises the question of toxicity that need to be managed, especially with longer survival of patients. In this article, we review different anti-HER2 therapies used in HER2-positive m etastatic breast cancer.

Metastatic human epidermal growth factor receptor 2-positive breast cancer: Management, challenges, and future directions

HER2 is over-expressed or amplified in 15-20% of breast cancer. Significant progress has been made in the treatment of metastatic HER2+ breast cancer. This is largely due to successful targeting of the HER2 pathway. There are several approved agents in the metastatic setting. However, treatment resistance frequently develops and tumors eventually progress. In recent years, our understanding of mechanisms of resistance has evolved. It is generally accepted now that HER2-positive breast cancer is not one disease. New therapeutic strategies and a tailored approach to management are necessary to maximize patient outcomes and minimize toxicity.

More than just the median: Calculating survival times for patients with HER2 positive, metastatic breast cancer using data from recent randomised trials

OBJECTIVES

To estimate worst-case, typical and best-case scenarios for survival as a communication aid for managing patients with HER2-positive metastatic breast cancer (MBC) starting HER2-targeted therapies.

METHODS

We sought randomised trials of HER2-targeted therapies and recorded the following percentiles (representative scenarios) from each OS curve: 90th (worst-case), 75th (lower-typical), 50th (median), 25th (upper-typical) and 10th (best-case). We then tested whether we could estimate these percentiles for each OS curve by multiplying its median by four simple multiples: 0.25 (to derive the 90th percentile), 0.5 (75th), 2 (25th) and 3 (10th). Estimates were deemed accurate if within 0.75-1.33 times the actual value.

RESULTS

We identified 15 trials with 4798 patients. For first-line, single-agent HER2-targeted therapy (15 treatment groups), the median (interquartile range [IQR]) for median OS was 33.3 months (29.1-38.4), and for each percentile was: 90th 9.5 months (7.7-11.0); 75th 19.2 months (16.4-20.8); and 25th 50.6 months (47.1-63.3). The 10th percentile was unavailable for all treatment groups. For first-line dual HER2-targeted therapy (1 treatment group), the median OS was 56.5 months. Simple multiples of the median OS accurately estimated the: 90th percentile in 79%; 75th percentile in 100%; and 25th percentile in 89% of OS curves.

CONCLUSIONS

Surprisingly little is known of survival beyond the median for HER2-positive MBC. Longer trial follow-up is required to help clinicians estimate and explain the best-case scenario. Simple multiples of the median OS provide a reasonable framework for estimating then explaining survival times to patients.

Chemotherapy versus endocrine therapy as first-line treatment in patients with luminal-like HER2-negative metastatic breast cancer: A propensity score analysis

BACKGROUND

According to current guidelines, endocrine therapy (ET) is recommended as first-line treatment of luminal-like metastatic breast cancer (MBC), whereas chemotherapy (CT) should be considered in presence of life-threatening disease. In daily practice, CT is often used outside of this clinical circumstance. Factors influencing first-line choice and the relative impact on outcome are unknown.

METHODS

A consecutive series of luminal-like HER2-negative MBC patients treated from 2004 to 2014 was analyzed to test the association of disease- and patient-related factors with the choice of first-line treatment (ET vs. CT). A propensity score method was used to estimate impact of first-line strategy on outcome.

RESULTS

Of 604 consecutive luminal-like MBC patients identified, 158 cases were excluded due to unknown or positive HER2-status. Among 446 HER2-negative cases, 171 (38%) received first-line CT. On multivariate analysis, the only factors significantly associated with lower CT use were old age (OR 0.25, 95%C.I. 0.13-0.49) or presence of bone metastases only (OR 0.26, 95%C.I. 0.13-0.53). In propensity score matched population, no differences were observed between CT and ET as first-line treatment either in terms of overall survival (37.5 months and 33.4 months respectively, log-rank test, P = 0.62) or progression-free survival (13.3 months and 9.9 months respectively, log-rank test, P = 0.92).

CONCLUSIONS

High percentage of patients with luminal-like MBC received CT as first-line therapy in real-life. The choice was mainly driven by age and site of metastases. With the limitations of a non-randomized comparison, no differences on patients' outcome were observed depending on the first-line strategy.