Targeted agents for HER2-positive breast cancer in older adults: current and future perspectives

HER-2 Neu gene: A valuable therapeutic target in metastatic mucoepidermoid carcinoma

INTRODUCTION

Salivary gland neoplasms (SGNs) respond poorly to the traditional chemotherapy agents limiting the availability of systemic treatment options in the metastatic setting. The recent identification of actionable molecular targets in SGNs has led to the evaluation of targeted therapies in non-approved advanced SGNs.

CASE REPORT

We present the case of an elderly male with HER-2 Neu overexpressing metastatic mucoepidermoid carcinoma (MEC) who demonstrated a prompt and sustained disease response to targeted therapies directed against HER-2 Neu with long survival interrupted by hepatoxicity to Trastuzumab emtansine (TDM-1) treatment.Management and Outcome: The patient was started on Trastuzumab and Pertuzumab on a clinical trial and resulted in an objective improvement sustained over 3 years. Following the disease progression, TDM-1 was started with a response until the patient developed severe hepatotoxicity as an adverse effect of TDM-1 therapy resulting in its discontinuation. Close follow-up post-treatment-discontinuation demonstrated continued clinical improvement until 6 months, when the patient developed brain metastasis. He passed away a few months later in hospice care.

DISCUSSION

The metastatic MEC in our patient overexpressed HER-2 Neu. Owing to Trastuzumab and Pertuzumab response, Trastuzumab emtansine (TDM-1) was initiated on a compassionate basis which further extended the survival but had to be terminated owing to adverse effects. Given the paucity of data on targeted therapies in the treatment of metastatic SGNs and the safety, tolerability, and efficacy of TDM-1 therapy among the elderly, further studies are warranted to answer these important questions and to identify eligible patients for this novel treatment option.

Phase II study of neratinib in older adults with HER2 amplified or HER2/3 mutated metastatic breast cancer

OBJECTIVE

The tolerability and efficacy of targeted therapy in older adults with cancer has not been adequately studied. Neratinib is a novel HER1, HER2, HER4 tyrosine kinase inhibitor that has recently been granted FDA approval for treatment of breast cancer. The major toxicity of neratinib is diarrhea, which affects up to 90% of patients. This phase II trial evaluates the safety and tolerability of neratinib in adults ≥60.

METHODS

Patients aged 60 or older with histologically proven metastatic breast cancer and HER2 amplification (defined by ASCO/CAP guideline) or HER2/HER3 activating mutation were enrolled to receive neratinib at 240 mg daily in 28-day cycles. The association between tolerability, defined as dose reduction and number of completed courses, and log2 Cancer and Aging Research Group (CARG) toxicity risk score was assessed using a Student's t-test and linear regression, respectively. Response rate, progression free survival, and overall survival were also evaluated.

RESULTS

25 patients were enrolled with median age of 66 (range 60-79). Seventy-six percent of patients were white, 16% Asian, and 8% African-American. Seventy-six percent were patients with hormone receptor (HR) positive metastatic breast cancer (MBC) and 24% were patients with HR negative MBC. Median number of prior lines of metastatic therapy were 3 (range 0-11). 20/25 (80%) had worst grade toxicities ≥2. A total of 9/25 (36%) had grade 3 toxicities including 5/20 (20%) diarrhea, 2/20 (8%) vomiting, and 2/20 (8%) abdominal pain. There were no grade 4 or 5 toxicities. A total of 9/25 (36%) had dose reduction, and 2/25 (8%) discontinued therapy due to toxicity. The association between dose reductions and CARG toxicity score reached borderline statistical significance suggesting a trend with participants with higher CARG toxicity risk scores being more likely to require a dose modification (p = 0.054). 1/25 (4%) had a partial response, 11/25 (44%) had stable disease, 12/25 (48%) had progression of disease, and 1/25 (4%) was not assessed. Median progression free survival (PFS) was 2.6 months (95% CI [2.56-5.26]), and median overall survival (OS) was 17.4 months (95% CI [10.3, NA]).

CONCLUSIONS

Neratinib was safe in this population of older adults with HER2 amplified or HER2/3 mutated metastatic breast cancer (BC). Higher CARG toxicity risk score may be associated with greater need for dose adjustments. Future studies are needed to confirm this finding.

HER2-targeted regimens after prior trastuzumab for patients with HER2-positive unresectable, locally advanced or metastatic breast cancer: a network meta-analysis of randomized controlled trials

Background

Several human epidermal growth factor receptor 2 (HER2)-targeted regimens (anti-HER2 target agent combined chemotherapy) have been introduced for the treatment of HER2-positive locally advanced or metastatic breast cancer progressed after trastuzumab. We therefore conducted a network meta-analysis to compare and rank HER2-targeted regimens in this population after trastuzumab therapy.

Methods

The electronic databases of PubMed, EmBase, Cochrane Central Register of Controlled Trials, and the websites of http://clinicaltrials.gov/ (US NIH) were systematically searched for published and unpublished randomized controlled trials (RCTs) from their inception to October, 2020. Nine treatment regimens were eligible to be included in this analysis. The primary outcomes were overall response rate (ORR), progression-free survival (PFS) and overall survival (OS), while the secondary outcomes were grade ≥3 adverse events.

Results

A total of 2,104 citations were identified and 12 RCTs comprising 3,769 patients were selected for final analysis. For HER2 positive unresectable, locally advanced or metastatic patients progressed after trastuzumab therapy pyrotinib plus capecitabine ranked the highest surface under the cumulative ranking area (SUCRA) in PFS, ORR and its SUCRA in OS was higher than Trastuzumab emtansine (T-DM1). T-DM1 plus atezolizumab, pyrotinib plus capecitabine, and pertuzumab plus trastuzumab plus capecitabine had comparable SUCRA in OS (76.1% vs. 74.5% vs. 71.2%). Six of included studies reported any grade ≥3 adverse events, the prevalence of any grade ≥3 adverse events in lapatinib plus capecitabine (353/683), T-DM1 (213/558), trastuzumab plus capecitabine (130/218), pertuzumab plus trastuzumab plus capecitabine (118/228), pyrotinib plus capecitabine (220/384), T-DM1 plus atezolizumab (43/132) and capecitabine (24/94) were 51.7%, 38.2%, 59.6%, 51.8%, 57.3%, 32.6% and 25.5%, respectively. Specific adverse event characteristics related to different HER2-targeted regimens need to be well known ahead and managed during the therapy.

Conclusions

The results indicated that for HER2 positive breast cancer with previous trastuzumab therapy pyrotinib plus capecitabine was probably more efficacious in PFS and ORR. T-DM1 plus atezolizumab, pyrotinib plus capecitabine and pertuzumab plus trastuzumab plus capecitabine have comparable effect on OS improvement and all of them were likely better than T-DM1. The risk of grade ≥3 adverse events for specific treatment regimens were also provided.

HER2 Signaling in Breast Cancer

HER2 gene amplification occurs in many breast cancer patients and is associated with poor clinical prognosis. Trastuzumab is a therapeutic monoclonal antibody binding to HER2 and inhibits growth of HER2-positive breast cancer cells and used as a principal treatment for HER2-positive breast cancer. Unfortunately, some HER2-positive breast cancers eventually relapse after trastuzumab treatment. To investigate the molecular mechanism of trastuzumab resistance, we generated trastuzumab-resistant cells using a mouse model and found ECM1 protein is increased in trastuzumab-resistant cells. ECM1 was shown to increase EGFR signaling via upregulated matrix metalloproteinase 9/galectin-3/mucin pathway. To further find the novel mediators of HER2-driven signaling pathways in breast cancer, we investigated the upregulated proteins in HER2-overexpressing breast cancer cells using a proteomics approach and found that KRT19 is strongly upregulated in HER2-positive breast cancer cells and it activates HER2 signaling by binding to HER2 and stabilizes the receptor on the cell membrane. Moreover, we found that treatment of KRT19 antibody resulted in reduced cell viability of trastuzumab-resistant HER2-positive breast cancer cells as well as trastuzumab-sensitive cancer cells both in vitro and in vivo.

Systemic Therapy of Common Tumours in Older Patients: Challenges and Opportunities. A Young International Society of Geriatric Oncology Review Paper

PURPOSE OF REVIEW

Decision-making for systemic treatments in older patients with cancer is difficult because of concerns for decreased organ function, risk of toxicity, limited life expectancy due to comorbidities and the lack of evidence available to guide its management in this population. Here, we review the data on the role of systemic agents for the treatment of common malignancies in this age group.

RECENT FINDINGS

Evidence on the use of systemic treatments for older patients with cancer is increasing, especially for newer options including immune checkpoint inhibitors and targeted agents that provide comparable benefit in older and younger patients. Nonetheless, the risks for short- and long-term toxicities need to be considered. More research is warranted and represents a unique opportunity to increase the knowledge on cancer treatment for older adults. Healthy, older individuals should be considered for standard systemic treatment options, whereas those at risk based on geriatric assessments require adjusted plans. Geriatric assessments are key for decision-making.

Hormonal treatment combined with targeted therapies in endocrine-responsive and HER2-positive metastatic breast cancer

Approximately 50% of HER2 positive breast cancer cases are also estrogen receptor (ER) positive. Data supports a role for close cross-talk between the ER and HER2 signaling pathways as an important contributor to the development of de novo or acquired resistance to hormone therapies. Therefore a strategy that simultaneously blocks both signaling pathways is a reasonable approach to prevent or overcome either endocrine or anti-HER2 therapy resistance. Moreover, preclinical data support the idea that PI3K inhibitors and CDK4/6 could be an attractive target that functions downstream of both ER and HER2 pathways. We conducted a literature review of the results of phase II and III studies testing targeted therapies in metastatic breast cancer with HER2-positive and hormonal-receptor-positive disease. The analyses included efficacy and toxicity data from earlier studies with a single anti-HER2 drug combined with hormonal therapy up to more recent studies testing new molecules targeting these signaling pathways. The aims of this review are to summarize current knowledge and to discuss research development including the possibility to spare chemotherapy in this subgroup of HER2-positive breast cancer patients.

Clinical efficacy of combination of pertuzumab, trastuzumab, and docetaxel for treatment of patients with HER2-positive breast cancer

BACKGROUND

This study will systematically investigate the efficacy and safety of the combination of pertuzumab, trastuzumab, and docetaxel (PTD) for treatment of patients with HER2-positive breast cancer (HER2-PBC).

METHODS

A comprehensive literature search for this study will consist of 2 parts: electronic database records and gray literature. The electronic database literatures are searched from PubMed, EMBASE, Cochrane Library, Web of Science, Google Scholar, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. All databases will be searched from inception up to the present. In addition, gray literatures, such as dissertations, ongoing trials, and so on, will also be searched. Two authors will independently read the records, extract data collection, and evaluate the risk of bias. RevMan V.5.3 software will be applied for statistical analysis.

RESULTS

This study will summarize up-to-date evidence of PTD for patients with HER2-PBC via overall survival, complete response, cancer-specific survival, recurrence-free survival, disease-free survival, quality of life, and toxicities.

CONCLUSION

This study will provide efficacy and safety of PTD for HER2-PBC.

Role of oxidative stress in cardiotoxicity of antineoplastic drugs

Tumors and heart disease are two of the leading causes of human death. With the development of anti-cancer therapy, the survival rate of cancer patients has been significantly improved. But at the same time, the incidence of cardiovascular adverse events caused by cancer treatment has also been considerably increased, such as arrhythmia, left ventricular (LV) systolic and diastolic dysfunction, and even heart failure (HF), etc., which seriously affects the quality of life of cancer patients. More importantly, the occurrence of adverse events may lead to the adjustment or the cessation of anti-cancer treatment, which affects the survival rate of patients. Understanding the mechanism of cardiotoxicity (CTX) induced by antineoplastic drugs is the basis of adequate protection of the heart without impairing the efficacy of antineoplastic therapy. Based on current research, a large amount of evidence has shown that oxidative stress (OS) plays an essential role in CTX induced by antineoplastic drugs and participates in its toxic reaction directly and indirectly. Here, we will review the mechanism of action of OS in cardiac toxicity of antineoplastic drugs, to provide new ideas for researchers, and provide further guidance for clinical prevention and treatment of cardiac toxicity of anti-tumor drugs in the future.

Recent advances in breast cancer research impacting clinical diagnostic practice

During the last decade, the genomics revolution has driven critical advances in molecular oncology and pathology, and a deeper appreciation of heterogeneity that is beginning to reshape our thinking around diagnostic classification. Recent developments have seen existing classification systems modified and improved where possible, gene-based diagnostics implemented and tumour-immune interactions modulated. We present a detailed discussion of this progress, including advances in the understanding of breast tumour classification, e.g. mixed ductal-lobular tumours and the spectrum of triple-negative breast cancer. The latest information on clinical trials and the implementation of gene-based diagnostics, including MammaPrint and Oncotype Dx and others, is synthesised, and emerging targeted therapies, as well as the burgeoning immuno-oncology field, and their relevance in breast cancer, are discussed. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Current Updates on Trastuzumab Resistance in HER2 Overexpressing Breast Cancers

Trastuzumab represents the predominant therapy to target breast cancer subtype marked by HER2 amplification. It has been in use for two decades and its continued importance is underlined by recent FDA approvals of its biosimilar and conjugated versions. Progression to an aggressive disease with acquisition of resistance to trastuzumab remains a major clinical concern. In addition to a number of cellular signaling pathways being investigated, focus in recent years has also shifted to epigenetic and non-coding RNA basis of acquired resistance against trastuzumab. This article provides a succinct discussion on the most recent advances in our understanding of such factors.