Dissecting the biological heterogeneity of HER2-positive breast cancer

HER2/PI3K/AKT pathway in HER2-positive breast cancer: A review

Breast cancer is currently the most commonly occurring cancer globally. Among breast cancer cases, the human epidermal growth factor receptor 2 (HER2)-positive breast cancer accounts for 15% to 20% and is a crucial focus in the treatment of breast cancer. Common HER2-targeted drugs approved for treating early and/or advanced breast cancer include trastuzumab and pertuzumab, which effectively improve patient prognosis. However, despite treatment, most patients with terminal HER2-positive breast cancer ultimately suffer death from the disease due to primary or acquired drug resistance. The prevalence of aberrantly activated the protein kinase B (AKT) signaling in HER2-positive breast cancer was already observed in previous studies. It is well known that p-AKT expression is linked to an unfavorable prognosis, and the phosphatidylinositol-3-kinase (PI3K)/AKT pathway, as the most common mutated pathway in breast cancer, plays a major role in the mechanism of drug resistance. Therefore, in the current review, we summarize the molecular alterations present in HER2-positive breast cancer, elucidate the relationships between HER2 overexpression and alterations in the PI3K/AKT signaling pathway and the pathways of the alterations in breast cancer, and summarize the resistant mechanism of drugs targeting the HER2-AKT pathway, which will provide an adjunctive therapeutic rationale for subsequent resistance to directed therapy in the future.

Distinct ER and PR expression patterns significantly affect the clinical outcomes of early HER2-positive breast cancer: A real-world analysis of 871 patients treated with neoadjuvant therapy

INTRODUCTION

The impact of distinct estrogen receptor (ER) and progesterone receptor (PR) expression patterns on tumor behavior and treatment outcomes within HER2-positive breast cancer is not fully explored. This study aimed to comprehensively examine the clinical differences among patients with HER2-positive breast cancer harboring distinct ER and PR expression patterns in the neoadjuvant setting.

METHODS

This retrospective analysis included 871 HER2-positive breast patients treated with neoadjuvant therapy at our hospital between 2011 and 2022. Comparisons were performed across the three hormone receptor (HR)-specific subtypes, namely the ER-negative/PR-negative/HER2-positive (ER-/PR-/HER2+), the single HR-positive (HR+)/HER2+, and the triple-positive breast cancer (TPBC) subtypes.

RESULTS

Of 871 patients, 21.0% had ER-/PR-/HER2+ tumors, 33.6% had single HR+/HER2+ disease, and 45.4% had TPBC. Individuals with single HR+/HER2+ tumors and TPBC cases demonstrated significantly lower pathological complete response (pCR) rates compared to those with ER-/PR-/HER2+ tumors (36.9% vs. 24.3% vs. 49.2%, p < 0.001). Multivariate analysis confirmed TPBC as significantly associated with decreased pCR likelihood (OR = 0.42, 95%CI 0.28-0.63, p < 0.001). Survival outcomes, including disease-free survival (DFS) and overall survival (OS), showed no significant differences across HR-specific subtypes in the overall patient population. However, within patients without anti-HER2 therapy, TPBC was linked to improved DFS and a trend towards better OS.

CONCLUSIONS

HER2-positive breast cancer exhibited three distinct HR-specific subtypes with varying clinical manifestations and treatment responses. These findings suggest personalized treatment strategies considering ER and PR expression patterns, emphasizing the need for further investigations to unravel molecular traits underlying HER2-positive breast cancer with distinct HR expression patterns.

Advancing HER2-low breast cancer management: enhancing diagnosis and treatment strategies

BACKGROUND

Recent evidence brought by novel anti-human epidermal growth factor receptor 2 (HER2) antibody-drug conjugates is leading to significant changes in HER2-negative breast cancer (BC) best practices. A new targetable category termed 'HER2-low' has been identified in tumors previously classified as 'HER2-negative'. Daily practice in pathology and medical oncology is expected to align to current recommendations, but patient access to novel anticancer drugs across geographies might be impeded due to local challenges.

MATERIALS AND METHODS

An expert meeting involving ten regional pathology and oncology opinion leaders experienced in BC management in four Central and Eastern Europe (CEE) countries (Bulgaria, Croatia, Serbia, Slovenia) was held. Herein we summarized the current situation of HER2-low metastatic BC (mBC), local challenges, and action plans to prevent delays in patient access to testing and treatment based on expert opinion.

RESULTS

Gaps and differences at multiple levels were identified across the four countries. These included variability in the local HER2-low epidemiology data, certification of pathology laboratories and quality control, and reimbursement conditions of testing and anticancer drugs for HER2-negative mBC. While clinical decisions were aligned to international guidelines in use, optimal access to testing and innovative treatment was restricted due to significant delays in reimbursement or limitative reimbursement conditions.

CONCLUSIONS

Preventing delays in HER2-low mBC patient access to diagnosis and novel treatments is crucial to optimize outcomes. Multidisciplinary joint efforts and pro-active discussions between clinicians and decision makers are needed to improve care of HER2-low mBC patients in CEE countries.

Management of early-stage HER2-positive breast cancer and attitudes towards HER2DX test in Spain: insights from a nationwide survey

PURPOSE

This study aimed to investigate the current therapeutic management of patients with early-stage HER2-positive (HER2+) breast cancer in Spain, while also exploring the perceptions surrounding HER2DX in terms of its credibility, clinical relevance, and impact on therapeutic decision-making. Understanding these aspects is crucial for optimizing treatment strategies and enhancing patient outcomes in the context of HER2+ breast cancer.

METHODS

An online questionnaire was conducted by an independent third-party between April and May 2022 across 70 medical oncologists highly specialized in breast cancer management in Spain. The survey included 37 questions regarding treatment decision making in HER2+ early breast cancer.

RESULTS

The management of patients with HER2+ early breast cancer exhibited a high degree of heterogeneity. Among the interviewed oncologists, 53% would recommend upfront surgery for node negative tumors measuring 1 cm or less. Interestingly, 69% and 56% of interviewers were open to deescalate the duration of adjuvant trastuzumab in pT1a and pT1b N0 tumors, respectively. Certain clinicopathological characteristics, such as high grade, high Ki-67, and young age, influenced the decision to prescribe neoadjuvant treatment for patients with clinical stage 1 disease. In cases where neoadjuvant treatment was prescribed for cT1-2 N0 tumors, there was a wide variation in the choice of chemotherapeutic and anti-HER2 regimens. Regarding the use of adjuvant trastuzumab emtansine (T-DM1) in patients with residual disease after neoadjuvant therapy, there was diversity in practice, and a common concern emerged that T-DM1 might be overtreating some patients. HER2DX, as a diagnostic tool, was deemed trustworthy, and the reported scores were considered clinically useful. However, 86% of interviewees believed that a prospective trial was necessary before fully integrating the test into routine clinical practice.

CONCLUSION

In the context of early-stage HER2+ breast cancer in Spain, a notable diversity in therapeutic approaches was observed. The majority of interviewed medical oncologists acknowledged HER2DX as a clinically valuable test for specific patients, in line with the 2022 SEOM-GEICAM-SOLTI clinical guidelines for early-stage breast cancer. To facilitate the full integration of HER2DX into clinical guidelines, conducting prospective studies to further validate its efficacy and utility was recommended.

Clinicopathological and molecular predictors of [18F]FDG-PET disease detection in HER2-positive early breast cancer: RESPONSE, a substudy of the randomized PHERGain trial

BACKGROUND

The PHERGain study (NCT03161353) is assessing early metabolic responses to neoadjuvant treatment with trastuzumab-pertuzumab and chemotherapy de-escalation using a [18Fluorine]fluorodeoxyglucose-positron emission tomography ([18F]FDG-PET) and a pathological complete response-adapted strategy in HER2-positive (HER2+) early breast cancer (EBC). Herein, we present RESPONSE, a PHERGain substudy, where clinicopathological and molecular predictors of [18F]FDG-PET disease detection were evaluated.

METHODS

A total of 500 patients with HER2 + EBC screened in the PHERGain trial with a tumor size > 1.5 cm by magnetic resonance imaging (MRI) were included in the RESPONSE substudy. PET[-] criteria entailed the absence of  ≥ 1 breast lesion with maximum standardized uptake value (SUVmax) ≥ 1.5 × SUVmean liver + 2 standard deviation. Among 75 PET[-] patients screened, 21 with SUVmax levels < 2.5 were randomly selected and matched with 21 PET[+] patients with SUVmax levels ≥ 2.5 based on patient characteristics associated with [18F]FDG-PET status. The association between baseline SUVmax and [18F]FDG-PET status ([-] or [+]) with clinicopathological characteristics was assessed. In addition, evaluation of stromal tumor-infiltrating lymphocytes (sTILs) and gene expression analysis using PAM50 and Vantage 3D™ Cancer Metabolism Panel were specifically compared in a matched cohort of excluded and enrolled patients based on the [18F]FDG-PET eligibility criteria.

RESULTS

Median SUVmax at baseline was 7.2 (range, 1-39.3). Among all analyzed patients, a higher SUVmax was associated with a higher tumor stage, larger tumor size, lymph node involvement, hormone receptor-negative status, higher HER2 protein expression, increased Ki67 proliferation index, and higher histological grade (p < 0.05). [18F]FDG-PET [-] criteria patients had smaller tumor size (p = 0.014) along with the absence of lymph node involvement and lower histological grade than [18F]FDG-PET [+] patients (p < 0.01). Although no difference in the levels of sTILs was found among 42 matched [18F]FDG-PET [-]/[+] criteria patients (p = 0.73), [18F]FDG-PET [-] criteria patients showed a decreased risk of recurrence (ROR) and a lower proportion of PAM50 HER2-enriched subtype than [18F]FDG-PET[+] patients (p < 0.05). Differences in the expression of genes involved in cancer metabolism were observed between [18F]FDG-PET [-] and [18F]FDG-PET[+] criteria patients.

CONCLUSIONS

These results highlight the clinical, biological, and metabolic heterogeneity of HER2+ breast cancer, which may facilitate the selection of HER2+ EBC patients likely to benefit from [18F]FDG-PET imaging as a tool to guide therapy.

TRIAL REGISTRATION

Clinicaltrials.gov; NCT03161353; registration date: May 15, 2017.

Advances in the study of tertiary lymphoid structures in the immunotherapy of breast cancer

Breast cancer, as one of the most common malignancies in women, exhibits complex and heterogeneous pathological characteristics across different subtypes. Triple-negative breast cancer (TNBC) and HER2-positive breast cancer are two common and highly invasive subtypes within breast cancer. The stability of the breast microbiota is closely intertwined with the immune environment, and immunotherapy is a common approach for treating breast cancer.Tertiary lymphoid structures (TLSs), recently discovered immune cell aggregates surrounding breast cancer, resemble secondary lymphoid organs (SLOs) and are associated with the prognosis and survival of some breast cancer patients, offering new avenues for immunotherapy. Machine learning, as a form of artificial intelligence, has increasingly been used for detecting biomarkers and constructing tumor prognosis models. This article systematically reviews the latest research progress on TLSs in breast cancer and the application of machine learning in the detection of TLSs and the study of breast cancer prognosis. The insights provided contribute valuable perspectives for further exploring the biological differences among different subtypes of breast cancer and formulating personalized treatment strategies.

Rational Identification of Novel Antibody-Drug Conjugate with High Bystander Killing Effect against Heterogeneous Tumors

Bystander-killing payloads can significantly overcome the tumor heterogeneity issue and enhance the clinical potential of antibody-drug conjugates (ADC), but the rational design and identification of effective bystander warheads constrain the broader implementation of this strategy. Here, graph attention networks (GAT) are constructed for a rational bystander killing scoring model and ADC construction workflow for the first time. To generate efficient bystander-killing payloads, this model is utilized for score-directed exatecan derivatives design. Among them, Ed9, the most potent payload with satisfactory permeability and bioactivity, is further used to construct ADC. Through linker optimization and conjugation, novel ADCs are constructed that perform excellent anti-tumor efficacy and bystander-killing effect in vivo and in vitro. The optimal conjugate T-VEd9 exhibited therapeutic efficacy superior to DS-8201 against heterogeneous tumors. These results demonstrate that the effective scoring approach can pave the way for the discovery of novel ADC with promising bystander payloads to combat tumor heterogeneity.

LncRNAs in necroptosis: Deciphering their role in cancer pathogenesis and therapy

Necroptosis, a controlled type of cell death that is different from apoptosis, has become a key figure in the aetiology of cancer and offers a possible target for treatment. A growing number of biological activities, including necroptosis, have been linked to long noncoding RNAs (lncRNAs), a varied family of RNA molecules with limited capacity to code for proteins. The complex interactions between LncRNAs and important molecular effectors of necroptosis, including mixed lineage kinase domain-like pseudokinase (MLKL) and receptor-interacting protein kinase 3 (RIPK3), will be investigated. We will explore the many methods that LncRNAs use to affect necroptosis, including protein-protein interactions, transcriptional control, and post-transcriptional modification. Additionally, the deregulation of certain LncRNAs in different forms of cancer will be discussed, highlighting their dual function in influencing necroptotic processes as tumour suppressors and oncogenes. The goal of this study is to thoroughly examine the complex role that LncRNAs play in controlling necroptotic pathways and how that regulation affects the onset and spread of cancer. In the necroptosis for cancer treatment, this review will also provide insight into the possible therapeutic uses of targeting LncRNAs. Techniques utilising LncRNA-based medicines show promise in controlling necroptotic pathways to prevent cancer from spreading and improve the effectiveness of treatment.

Analytical validation of HER2DX genomic test for early-stage HER2-positive breast cancer

BACKGROUND

HER2DX, a multianalyte genomic test, has been clinically validated to predict breast cancer recurrence risk (relapse risk score), the probability of achieving pathological complete response post-neoadjuvant therapy (pCR likelihood score), and individual ERBB2 messenger RNA (mRNA) expression levels in patients with early-stage human epidermal growth factor receptor 2 (HER2)-positive breast cancer. This study delves into the comprehensive analysis of HER2DX's analytical performance.

MATERIALS AND METHODS

Precision and reproducibility of HER2DX risk, pCR, and ERBB2 mRNA scores were assessed within and between laboratories using formalin-fixed paraffin-embedded (FFPE) tumor tissues and purified RNA. Robustness was appraised by analyzing the impact of tumor cell content and protocol variations including different instruments, reagent lots, and different RNA extraction kits. Variability was evaluated across intratumor biopsies and genomic platforms [RNA sequencing (RNAseq) versus nCounter], and according to protocol variations.

RESULTS

Precision analysis of 10 FFPE tumor samples yielded a maximal standard error of 0.94 across HER2DX scores (1-99 scale). High reproducibility of HER2DX scores across 29 FFPE tumors and 20 RNAs between laboratories was evident (correlation coefficients >0.98). The probability of identifying score differences >5 units was ≤5.2%. No significant variability emerged based on platform instruments, reagent lots, RNA extraction kits, or TagSet thaw/freeze cycles. Moreover, HER2DX displayed robustness at low tumor cell content (10%). Intratumor variability across 212 biopsies (106 tumors) was <4.0%. Concordance between HER2DX scores from 30 RNAs on RNAseq and nCounter platforms exceeded 90.0% (Cohen's κ coefficients >0.80).

CONCLUSIONS

The HER2DX assay is highly reproducible and robust for the quantification of recurrence risk, pCR likelihood, and ERBB2 mRNA expression in early-stage HER2-positive breast cancer.

Prognostic value of HER2DX in early-stage HER2-positive breast cancer: a comprehensive analysis of 757 patients in the Sweden Cancerome Analysis Network-Breast dataset (SCAN-B)

BACKGROUND

The HER2DX risk-score has undergone rigorous validation in prior investigations involving patients with early-stage human epidermal growth factor receptor 2 (HER2)-positive (HER2+) breast cancer. In this study, we present the outcomes of the HER2DX risk-score within the most recent release of the Sweden Cancerome Analysis Network-Breast (SCAN-B) HER2+ cohort. This updated examination benefits from a larger patient sample, an extended follow-up duration, and detailed treatment information.

MATERIALS AND METHODS

Clinical and RNAseq data from the SCAN-B dataset were retrieved from Gene Expression Omnibus (GSE81538). Among the 6600 patients, 819 had HER2+ breast cancer, with 757 individuals with research-based HER2DX risk-scores and corresponding survival outcomes. The HER2DX risk-score was evaluated (i) as a continuous variable and (ii) using predefined cut-offs. The primary endpoint for this study was overall survival (OS). The Kaplan-Meier method and Cox models were used to estimate OS and a multistate model with four states was fitted to better characterize patients' follow-up.

RESULTS

The median follow-up time was 7.5 years (n = 757). The most common systemic therapy was chemotherapy with trastuzumab (82.0%) and most tumors were classified as T1-T2 (97.1%). The HER2DX risk-score as a continuous variable was significantly associated with OS after adjustment for clinical variables and treatment regimen [hazard ratios (HR) per 10-unit increment = 1.31, 95% confidence interval (CI) 1.13-1.51, P < 0.001] as well as within predefined risk groups (high versus low; HR = 2.57, 95% CI 1.36-4.85, P < 0.001). Patients classified as HER2DX high-risk also had higher risk of (i) breast cancer recurrence and (ii) death without previous recurrence. Within the subgroup of HER2+ T1N0 tumors (n = 297), those classified as high-risk demonstrated inferior OS compared to low-risk tumors (7-year OS 77.8% versus 96.8%, P < 0.001). The HER2DX mRNA ERBB2 score was associated with clinical HER2 status (area under the receiver operating characteristic curve = 0.91).

CONCLUSIONS

In patients with early-stage HER2+ breast cancer, HER2DX risk-score provides prognostic information beyond clinicopathological variables, including treatment regimen with or without trastuzumab.

Exploring Biomarkers in Breast Cancer: Hallmarks of Diagnosis, Treatment, and Follow-Up in Clinical Practice

Breast cancer is a prevalent malignancy in the present day, particularly affecting women as one of the most common forms of cancer. A significant portion of patients initially present with localized disease, for which curative treatments are pursued. Conversely, another substantial segment is diagnosed with metastatic disease, which has a worse prognosis. Recent years have witnessed a profound transformation in the prognosis for this latter group, primarily due to the discovery of various biomarkers and the emergence of targeted therapies. These biomarkers, encompassing serological, histological, and genetic indicators, have demonstrated their value across multiple aspects of breast cancer management. They play crucial roles in initial diagnosis, aiding in the detection of relapses during follow-up, guiding the application of targeted treatments, and offering valuable insights for prognostic stratification, especially for highly aggressive tumor types. Molecular markers have now become the keystone of metastatic breast cancer diagnosis, given the diverse array of chemotherapy options and treatment modalities available. These markers signify a transformative shift in the arsenal of therapeutic options against breast cancer. Their diagnostic precision enables the categorization of tumors with elevated risks of recurrence, increased aggressiveness, and heightened mortality. Furthermore, the existence of therapies tailored to target specific molecular anomalies triggers a cascade of changes in tumor behavior. Therefore, the primary objective of this article is to offer a comprehensive review of the clinical, diagnostic, prognostic, and therapeutic utility of the principal biomarkers currently in use, as well as of their clinical impact on metastatic breast cancer. In doing so, our goal is to contribute to a more profound comprehension of this complex disease and, ultimately, to enhance patient outcomes through more precise and effective treatment strategies.

Therapeutic resistance and optimal drug sequencing in HER2-positive metastatic breast cancer: unmet needs and future perspectives

In the last couple of decades substantial therapeutic improvements deeply influenced the treatment of HER2-positive metastatic breast cancer. The most impactful advancements were obtained especially in the first-line setting, with the trastuzumab/pertuzumab anti-HER2 double blockade, and in the second line, with the advent of the potent antibody-drug conjugate trastuzumab deruxtecan. Nevertheless, a careful observation of the patterns of early-progression and long-term effects on overall survival of the most novel agents and combinations, highlights the challenges represented by the emergence of therapeutic resistance and optimal drug sequencing. The integration of sequence studies, tumor-related biomarker development/implementation and understanding of primary mechanisms of resistance to novel anti-HER2 agents, will be the way to move forward to effectively tackle these novel unmet needs.

Metastatic site patterns by intrinsic subtype and HER2DX in early HER2-positive breast cancer

BACKGROUND

Even with contemporary treatment strategies, more than 10% of HER2-positive early stage breast cancer patients may experience distant metastasis as first event during follow-up. Tools for predicting unique patterns of metastatic spread are needed to plan personalized surveillance. We evaluated how molecular heterogeneity affects the pattern of distant relapse in HER2-positive breast cancer.

METHODS

A total of 677 HER2-positive stage I-III breast cancer patients from ShortHER trial, Cher-LOB trial, and 2 institutional cohorts were included. PAM50 molecular subtypes and research-based HER2DX scores were evaluated. The cumulative incidence of distant relapse as the first event (any site and site specific) was evaluated using competing risk analysis. Median follow-up was 8.4 years. Tests of statistical significance are 2-sided.

RESULTS

Stage III and high HER2DX risk score identified patients at the highest risk of distant relapse as first event (10-year incidence 24.5% and 19.7%, respectively). Intrinsic molecular subtypes were associated with specific patterns of metastatic spread: compared with other subtypes, HER2-enriched tumors were more prone to develop brain metastases (10-year incidence 3.8% vs 0.6%, P = .005), basal-like tumors were associated with an increased risk of lung metastases (10-year incidence 11.1% vs 2.6%, P = .001), and luminal tumors developed more frequently bone-only metastases (10-year incidence 5.1% vs 2.0%, P = .042). When added to stage or HER2DX risk score in competing risk regression models, intrinsic subtype maintained an independent association with site-specific metastases.

CONCLUSIONS

The integration of intrinsic molecular subtypes with stage or HER2DX risk score predicts site-specific metastatic risk in HER2-positive breast cancer, with potential implications for personalized surveillance and clinical trials aimed at preventing site-specific recurrence.

Evaluation of tumor-infiltrating lymphocytes, PD-L1, and PIK3CA mutations and association with prognosis in HER2-positive early stage breast cancer

BACKGROUND

Tumor-infiltrating lymphocytes (TILs) have predictive and prognostic potential in HER2-positive breast cancer (HER2+ BC). Programmed death-ligand 1 (PD-L1) is an immune checkpoint protein, with important roles in the tumor microenvironment, possibly in both tumor and immune cells (ICs), providing rationale for targeting with immune-checkpoint therapy. PIK3CA mutations are oncogenic, activating mutations, which are also of relevance in breast cancer. Herein, we investigate the frequency of TILs, PD-L1 and PIK3CA mutations, and whether these factors influence outcome, in early HER2+ BC.

MATERIALS AND METHODS

Stromal TILs (sTILs) and PD-L1 expressions were assessed using full tumor-sections and TMA, respectively, from 236 patients with HER2+ BC. TILs were assessed, according to a standardized method, as continuous measurement and according to three predefined categories: low (0-10%), intermediate (11-59%), and high (60-100%). PD-L1 immunohistochemistry (Ventana SP263) was evaluated and positivity defined as ≥1% expression in tumor and ICs. PIK3CA mutations (exons 9 and 20) were determined by pyrosequencing.

RESULTS

Fourteen percent of patients had high sTILs and 25% had a PIK3CA mutation. PD-L1 expression was more frequent in ICs (68%) than tumor cells (24%). Patients with low sTILs had a significantly worse overall survival (multivariate: HR 2.80; 95% CI 1.36-5.78; p = .02).

DISCUSSION

Patients with low sTILs had a significantly poorer survival, despite adequate treatment with adjuvant therapy.

Clinical characteristics and treatment outcomes of HER2 mutation and HER2 fusion in 22 patients with advanced breast cancer

BACKGROUND

The clinical characteristics and efficacy of human epidermal growth factor receptor-2 (HER-2)-directed agents against HER2 mutations and HER2 fusions in breast cancer are obscure due to their low frequency.

METHODS

We conducted a retrospective study in patients with advanced breast cancer harboring HER2 mutations and/or HER2 fusions between January 1, 2017 and January 1, 2021.

RESULTS

Among a total of 22 patients, 17 HER2 mutations were detected, including L755S, S310F, R100=, V777L, R897W, T862A, 440-17C > G, H878Y, V842I, 73 + 9G > C, T278fs, E1069K, L755P, 226-11C > T, 574 + 12C>T, L114V and P128L. The majority of patients had ductal carcinoma, which mostly coexisted with HER2 amplification/overexpression. The median progression-free survival (PFS) of the 22 patients was 6.9 months (95% CI: 4.7, 9.1) in the first-line setting. The median PFS of patients who received first-line trastuzumab-based regimens was significantly longer than that of patients who received a first-line tyrosine kinase inhibitor (TKI) (10.8 months [95% CI: 2.9, 18.7] vs. 1.9 months [95% CI: 0.8, 3.0], p < 0.005). A total of 14 patients were treated with anti-HER2 antibody-drug conjugate (ADC), among whom the median treatment line of first-time of administration of anti-HER2 ADC was 4.5 (range, 1-10). Anti-HER2 ADC reached an objective response rate (ORR) of 42.9%, a disease control rate (DCR) of 85.7% and a median PFS of 7.3 months (95% CI: 4.4-10.1) from the first-time of administration.

CONCLUSION

Our data demonstrated the clinical benefit of anti-HER2 treatment in Chinese breast cancer patients harboring HER2 mutation and/or HER2 fusion. The value of immunotherapy and treatment selection among individual HER2 variants needs further study.

Network pharmacology-based approach to investigate the molecular targets of essential oil obtained from lavender for treating breast cancer

Lavender essential oil (LEO) is known for its medicinal use in the development of pharmaceuticals. Further investigations were demonstrated that LEO has many biological properties including apoptosis. However, The anti-breast cancer activity and mechanism of LEO are still unclear. we aim to elucidate the elusive anti-breast cancer activity and mechanism of LEO by unveiling the intricate molecular targets that it engages with, thereby priming it for effective therapeutic intervention against breast carcinoma. In this paper, we extracted LEO from lavender and analyzed it's chemical constituents by using hydro-distillation and gas chromatography-mass spectrometry (GS-MS/MS) method, respectively. The active components against breast cancer and it's molecular targets were selected and biological process, molecular function, cellular component and involving pathways were evaluated via network pharmacology approach. Cell viability, apoptosis and cell cycle assay were used to evaluate anti-breast cancer effect of LEO. Employing the western blotting method to validate target protein expression following LEO treatment in vitro. We found the 21 effective components and 213 drug-disease common targets of LEO. Amoung them, 7 active components and 19 targets were identified as potential therapeutic targets. Gene ontology results revealed that the drug-disease common targets of LEO were mainly distributed in membrane region, involved in peptide-tyrosine phosphorylation, and primarily associated with protein tyrosine kinase. We also found that drug-disease common targets might contribute to the regulation of PI3K-AKT signaling pathway by using KEGG pathway analysis. Besides, our study demonstrated reduced cell viability, induced apoptosis in MCF-7 and MDA-MB-231 treated with LEO while cell cycle arrest was not altered. The AKT1 expression down-regulated while PIK3CA expression was increased in both cell lines. Our findings indicate that LEO has the ability to induce apoptosis by modulating the expression of PI3K-AKT signaling pathway in these cell lines.

Potential diagnostic and prognostic biomarkers for breast cancer: A compiled review

Breast cancer is one of the major reason for death of women worldwide. As per the International Agency for Research on Cancer (IARC) statistics, the number of cases of breast cancer is increasing year by year in many parts of the world. As per the recent global cancer burden figures, in 2020, there were 2.26 million incidences of breast cancer cases and it is one of the main causes of mortality due to cancer in women in the world. Biomarkers of breast cancer would prove to be very beneficial to screen women who are at higher risk and for detection of disease recurrence. Here, studies carried out on biomarkers of breast cancer and susceptibility to the disease have been reviewed. Various databases like Google Scholar, ScienceDirect and PubMed have been used for searching and majorly literature from the last 10 years have been considered. Potential biomarkers of breast cancer including blood based angiogenic factors, glycoprotein-based biomarkers, hormone receptor biomarkers and other biomarkers that were identified from various studies have been summarized.

Neoadjuvant chemotherapy for breast cancer: an evaluation of its efficacy and research progress

Neoadjuvant chemotherapy (NAC) for breast cancer is widely used in the clinical setting to improve the chance of surgery, breast conservation and quality of life for patients with advanced breast cancer. A more accurate efficacy evaluation system is important for the decision of surgery timing and chemotherapy regimen implementation. However, current methods, encompassing imaging techniques such as ultrasound and MRI, along with non-imaging approaches like pathological evaluations, often fall short in accurately depicting the therapeutic effects of NAC. Imaging techniques are subjective and only reflect macroscopic morphological changes, while pathological evaluation is the gold standard for efficacy assessment but has the disadvantage of delayed results. In an effort to identify assessment methods that align more closely with real-world clinical demands, this paper provides an in-depth exploration of the principles and clinical applications of various assessment approaches in the neoadjuvant chemotherapy process.

The trichotomy of HER2 expression confers new insights into the understanding and managing for breast cancer stratified by HER2 status

Human epidermal growth factor receptor 2 (HER2) is a tyrosine kinase receptor that plays a carcinogenic role in breast cancer (BC) through gene amplification, mutation, or overexpression. Traditional methods of HER2 detection were divided into positive (immunohistochemistry (IHC) 3+/fluorescence in situ hybridization (FISH) amplification) and negative (IHC 2+/FISH-, IHC 1+, IHC 0) according to the dichotomy method. Anti-HER2-targeted therapies, such as trastuzumab and pertuzumab, have significantly improved the prognosis of HER2-positive patients. However, up to 75% to 85% of patients remain HER2-negative. In recent years, with the rapid development of molecular biology, gene detection technology, targeted therapy, and immunotherapy, researchers have actively explored the clinicopathological characteristics, molecular biological characteristics, treatment methods, and HER2 detection methods of HER2-low/zero breast cancer. With the clinical efficacy of new anti-HER2 targeted drugs, accurate classification of breast cancer is very important for the treatment choice. Therefore, the following review summarizes the necessity of developing HER2 detection methods, and the clinicopathological and drug treatment characteristics of patients with HER2-low/zero, to light the dawn of the treatment of breast cancer patients with HER2-low/zero expression.

New-generation technologies for spatial tissue analysis, indispensable tools for deciphering intratumor heterogeneity in the development of antibody-drug conjugates and radio-immunoconjugates for cancer treatment

Technologies allowing in situ tissue molecular analysis of the "high-plex" type (>20 molecules per tissue section) are the 21st century inventions that are revolutionizing our knowledge of the biology of malignant tumors and many benign alterations. These technologies are based on specific probe labeling systems for the detection of tissue components [proteins, messenger RNA (mRNA)], as well as on detailed image analysis, combined with computational tools. We are synthetically presenting technologies based on image analysis, such as multiplex immunofluorescence (mIF), imaging mass cytometry (IMC), and multiplexed ion beam imaging (MIBI), as well as the ones not based on image analysis, such as multiplex in situ hybridizations (ISHs) using various principles. All of them are supported by powerful software which enable both tissue segmentation and data analysis. In the context of cancer treatment personalization, these technologies can reveal areas of tumor tissue and/or cellular subpopulations that are responsible for good or bad responses to anticancer drugs. Thus, they represent an unprecedented aid in the exploration of intratumor heterogeneity (ITH), which has already been shown to be one of the main reasons for the therapeutic failure of targeted anticancer treatments. The arrival of antibody-drug conjugates (ADCs) and radio-immunoconjugates (RICs) in the therapeutic arsenal in oncology imposes a deep exploration of molecular ITH, where technologies of spatial tissue analysis reveal an emerging category of biomarkers-spatial biomarkers.

Effect of HER2 expression status on the prognosis of patients with HR+/HER2‑ advanced breast cancer undergoing advanced first‑line endocrine therapy

The present study aimed to retrospectively assess the effects of human epidermal growth factor receptor 2 (HER2) expression on the diagnosis of patients with hormone receptor (HR)⁺/HER2^- late-stage breast cancer undergoing advanced first-line endocrine-based treatment. A total of 72 late-stage breast tumor cases from June 2017 to June 2019 were selected from the Department of Surgical Oncology, Shaanxi Provincial People's Hospital (Xi'an, China) and included in the present study. The expression of estrogen receptor, progesterone receptor and HER2 was detected by immunohistochemistry. The subjects were divided into two groups: the HER2-negative (0) cohort (n=31) and the HER2 low expression cohort (n=41). The age, BMI, Karnofsky Performance Status (KPS) score, tumor size, lymph node metastasis, pathological type, Ki-67 expression and menopausal status of the patients were obtained through the electronic medical record system of Shaanxi Provincial People's Hospital. Progression-free survival (PFS) and overall survival (OS) were evaluated for all patients. The median PFS and OS of the HER2(0) cohort were longer than those of the HER2 low expression cohort (all P<0.05). It was shown that age (hazard ratio, 6.000 and 5.465), KPS score (hazard ratio, 4.000 and 3.865), lymph node metastasis (hazard ratio, 3.143; 2.983) and HER2 status (hazard ratio, 3.167 and 2.996) were independent influencing factors of the prognosis of patients with HR⁺/HER2^- advanced breast cancer (ABC) (all P<0.05). Three models (model 1, no parameters adjusted; model 2, BMI, tumor size, pathological type, Ki-67 and menopausal status adjusted; and model 3, age, KPS functional status score and lymph node metastasis adjusted based on model 2) were established within the HER2(0) cohort as the reference for statistical analysis using the multivariate Cox's regression test. In models 2 and 3, the risk of poor prognosis of ABC within the HER2 low expression cohort was significantly higher compared with that in the HER2(0) cohort (hazard ratio, 3.558 and 4.477; 95% CI, 1.349-9.996 and 1.933-11.586; P=0.003 and P<0.001). The HER2 expression status of patients with HR⁺/HER2^- ABC receiving advanced first-line endocrine therapy may affect PFS and OS.

Role of Surgical Pathologist for Detection of Predictive Immuno-oncological Factors in Breast Cancer

Immune checkpoint inhibitors (ICIs) have changed therapy strategies in breast cancer (BC) patients suffering from triple-negative breast cancer (TNBC). For example, in Europe the anti-programmed cell death 1 ligand 1 (PD-L1) ICI Azetolizumab is approved for adult patients with locally advanced or metastasized TNBC (mTNBC), depending on the immunohistochemical (IHC) PD-L1 expression of immune cells in the tumor area [immune cell (IC) score ≥1%); the anti-programmed cell death 1 (PD-1) ICI pembrolizumab is approved for mTNBC if PD-L1 Combined Positive Score (CPS), that is PD-L1 expression on tumor and/or immune cells, is ≥10. For early TNBC, in contrast, neoadjuvant use of pembrolizumab is approved in the United States and Europe independent from PD-L1 IHC expression. The determination of PD-L1 expression in tumor tissue to predict response to ICI therapy requires sensitive immunostaining with appropriate primary antibodies and staining protocols and a standardized and meticulous assessment of PD-L1 IHC stained breast cancer tissue slides. For the selection of the test material and continuous quality control of the dyeing, high standards must be applied. The evaluation is carried out according to various evaluation algorithms (scores). Here, the role of PD-L1 in BC and the currently most relevant PD-L1 assays and scores for TNBC will be explained. Furthermore, other tissue-based biomarkers potentially predictive for ICI therapy response in BC, for example, tumor mutational burden (TMB), will be presented in this review.

Target Antigen Attributes and Their Contributions to Clinically Approved Antibody-Drug Conjugates (ADCs) in Haematopoietic and Solid Cancers

Antibody drug conjugates (ADCs) are powerful anti-cancer therapies comprising an antibody joined to a cytotoxic payload through a chemical linker. ADCs exploit the specificity of antibodies for their target antigens, combined with the potency of cytotoxic drugs, to selectively kill target antigen-expressing tumour cells. The recent rapid advancement of the ADC field has so far yielded twelve and eight ADCs approved by the US and EU regulatory bodies, respectively. These serve as effective targeted treatments for several haematological and solid tumour types. In the development of an ADC, the judicious choice of an antibody target antigen with high expression on malignant cells but restricted expression on normal tissues and immune cells is considered crucial to achieve selectivity and potency while minimising on-target off-tumour toxicities. Aside from this paradigm, the selection of an antigen for an ADC requires consideration of several factors relating to the expression pattern and biological features of the target antigen. In this review, we discuss the attributes of antigens selected as targets for antibodies used in clinically approved ADCs for the treatment of haematological and solid malignancies. We discuss target expression, functions, and cellular kinetics, and we consider how these factors might contribute to ADC efficacy.

Construction of a prognostic risk assessment model for HER2 + breast cancer based on autophagy-related genes

Although breast cancer (BC) has a low mortality rate relative to other cancers, it prominently affects the survival of patients with human epidermal growth factor receptor-2 (HER2 +) BC due to its high recurrence rate. By far, it has been found that autophagy can affect various tumor occurrence and development, as well as patients' prognosis. HER2 + BC patient samples and autophagy-related genes (ARGs) were acquired from a public database, least absolute shrinkage and selection operator (LASSO) and Cox analyses (including univariate and multivariate analyses) were utilized to construct a 9-ARGs model, which was verified by using HER2 + BC patient samples in The Cancer Genome Atlas (TCGA) dataset. Sample risk score was worked out based on characteristic genes, and prominent differences in overall survival were tracked down between high- and low-risk groups. Predictive ability of the model was validated by drawing receiver operating characteristic (ROC) curves and then calculating the area under the curves (AUC) value. Results showed good accuracy and prediction ability of the model in both validation set and training set. For the purpose of facilitating model application in clinical practice, we constructed a nomogram combing clinical factors and risk scores to evaluate 1-year, 3-year and 5-year survival of HER2 + BC patients. In addition, we assessed the correlation of risk score with tumor mutational burden and tumor immune infiltration. Results exhibited that in a high-risk group, tumor mutation was relatively high, while tumor immune infiltration was relatively poor. Overall, based on ARGs, the prognostic signature in this study can tellingly evaluate prognoses of HER2 + BC patients and provide a reference for clinicians.

Adjuvant paclitaxel and trastuzumab for node-negative, HER2-positive breast cancer: final 10-year analysis of the open-label, single-arm, phase 2 APT trial

BACKGROUND

We aimed to report on long-term outcomes of patients with small, node-negative, HER2-positive breast cancer treated with adjuvant paclitaxel and trastuzumab and to establish potential biomarkers to predict prognosis.

METHODS

In this open-label, single-arm, phase 2 study, patients aged 18 years or older, with small (≤3 cm), node-negative, HER2-positive breast cancer, and an Eastern Cooperative Oncology Group performance status of 0-1, were recruited from 16 institutions in 13 cities in the USA. Eligible patients were given intravenous paclitaxel (80 mg/m²) with intravenous trastuzumab (loading dose of 4 mg/kg, subsequent doses 2 mg/kg) weekly for 12 weeks, followed by trastuzumab (weekly at 2 mg/kg or once every 3 weeks at 6 mg/kg) for 40 weeks to complete a full year of trastuzumab. The primary endpoint was 3-year invasive disease-free survival. Here, we report 10-year survival outcomes, assessed in all participants who received protocol-defined treatment, with exploratory analyses using the HER2DX genomic tool. This study is registered on ClinicalTrials.gov, NCT00542451, and is closed to accrual.

FINDINGS

Between Oct 29, 2007, and Sept 3, 2010, 410 patients were enrolled and 406 were given adjuvant paclitaxel and trastuzumab and included in the analysis. Mean age at enrolment was 55 years (SD 10·5), 405 (99·8%) of 406 patients were female and one (0·2%) was male, 350 (86·2%) were White, 28 (6·9%) were Black or African American, and 272 (67·0%) had hormone receptor-positive disease. After a median follow-up of 10·8 years (IQR 7·1-11·4), among 406 patients included in the analysis population, we observed 31 invasive disease-free survival events, of which six (19·4%) were locoregional ipsilateral recurrences, nine (29·0%) were new contralateral breast cancers, six (19·4%) were distant recurrences, and ten (32·3%) were all-cause deaths. 10-year invasive disease-free survival was 91·3% (95% CI 88·3-94·4), 10-year recurrence-free interval was 96·3% (95% CI 94·3-98·3), 10-year overall survival was 94·3% (95% CI 91·8-96·8), and 10-year breast cancer-specific survival was 98·8% (95% CI 97·6-100). HER2DX risk score as a continuous variable was significantly associated with invasive disease-free survival (hazard ratio [HR] per 10-unit increment 1·24 [95% CI 1·00-1·52]; p=0·047) and recurrence-free interval (1·45 [1·09-1·93]; p=0·011).

INTERPRETATION

Adjuvant paclitaxel and trastuzumab is a reasonable treatment standard for patients with small, node-negative, HER2-positive breast cancer. The HER2DX genomic tool might help to refine the prognosis for this population.

FUNDING

Genentech.

Optimizing treatment for HER2-positive HR-positive breast cancer

Triple-positive breast tumors overexpress human epidermal growth factor receptor 2 (HER2) and are positive for hormone receptor (HR) expression. Data from real-life and clinical trials show that estrogen receptor (ER) expression affects the response to combinations of anti-HER2 and associated systemic therapies. Despite triple-positive tumors having decreased response rates compared to HR-negative/HER2-positive breast cancers, optimizing anti-HER2 treatment with dual anti-HER2 blockade remains important for optimal disease control. Preclinical data on the cross-talk between ER and growth factor receptor pathways show the efficacy of combinations of endocrine therapy and anti-HER2 drugs, which is confirmed in the clinic. Molecular dissection of triple-positive breast cancer might provide the rational for additional therapeutic strategies and the identification of promising biomarkers. This review summarizes data on systemic treatment efficacy from major clinical trials and perspectives for future clinical research in triple-positive breast cancer.

The Great Immune Escape: Understanding the Divergent Immune Response in Breast Cancer Subtypes

Breast cancer, the most common type of cancer affecting women, encompasses a collection of histologic (mainly ductal and lobular) and molecular subtypes exhibiting diverse clinical presentation, disease trajectories, treatment options, and outcomes. Immunotherapy has revolutionized treatment for some solid tumors but has shown limited promise for breast cancers. In this review, we summarize recent advances in our understanding of the complex interactions between tumor and immune cells in subtypes of breast cancer at the cellular and microenvironmental levels. We aim to provide a perspective on opportunities for future immunotherapy agents tailored to specific features of each subtype of breast cancer.

SIGNIFICANCE

Although there are currently over 200 ongoing clinical trials testing immunotherapeutics, such as immune-checkpoint blockade agents, these are largely restricted to the triple-negative and HER2+ subtypes and primarily focus on T cells. With the rapid expansion of new in vitro, in vivo, and clinical data, it is critical to identify and highlight the challenges and opportunities unique for each breast cancer subtype to drive the next generation of treatments that harness the immune system.

The potential role of nanomedicine in the treatment of breast cancer to overcome the obstacles of current therapies

Breast cancer (BC) is the most frequently diagnosed malignant tumor among women in the world. BC is the heterogeneous tumor with different subtypes including luminal A-like, luminal B-like (HER2-/HER2+), HER2 enriched, and triple-negative BC. The therapeutic strategies including surgery, chemotherapy, radiotherapy, targeted therapy, and endocrine therapy are well developed and commonly used in the treatment of BC. However, some adverse effects of these conventional treatments limited their wide application in clinical. Therefore, it is necessary to develop more safe and more efficient individualized treatment strategies of the BC. Nanomedicine, as the most promising strategy for controlled and targeted drug delivery, is widely used in multiple aspects of cancer therapy. Importantly, accumulative evidences show that nanomedicine has achieved good outcomes in the treatment of BC and a huge amount of BC patients benefited from the nanomedicine related treatments. In this review, we summarized and discussed the major problems occurred during the administration of conventional treatment strategies for BC and the potential roles of nanomedicine in promoting the treatment efficacy of BC by overcoming obstacles of current treatment of BC.

Classification of breast cancer subtypes based on RNA profiling and immunohistochemical methods: clinical and biological aspects: A review

Transcriptome analysis provided a tool to identify expression subtypes of breast cancer (BC). A significant part of BCs are carcinomas that differ in the expression of luminal mammary ductal epithelium markers and estrogen signaling cascade genes (luminal subtypes A and B). Another group of BCs is characterized by the expression of ductal basal lining genes. Another subtype of BC has genes typically expressed in HER2-induced tumors. Immunohistochemical (IHC) examination is reliable in identifying the tumor subtype. Tumors with high IHC-expression of estrogen (ER) and progesterone (PR) receptors with no signs of HER2 gene activation and low proliferative activity should be referred to as luminal type A. The absence of ER, PR, and HER2 expression should be considered a sign of basal tumor subtype. However, the IHC classification cannot reliably distinguish HER2-positive tumors and HER2-enriched subtypes, which do not reflect the biological features of some BCs. For instance, a significant number of ER-positive breast cancer patients included in the MONALEESA ribociclib clinical study had HER2-subtype transcriptional signatures in the absence of HER2 receptor expression, and these were the ones who demonstrated a pronounced response to treatment.

HER2 mRNA Levels, Estrogen Receptor Activity and Susceptibility to Trastuzumab in Primary Breast Cancer

While the results thus far demonstrate the clinical benefit of trastuzumab in breast cancer (BC), some patients do not respond to this drug. HER2 mRNA, alone or combined with other genes/biomarkers, has been proven to be a powerful predictive marker in several studies. Here, we provide evidence of the association between HER2 mRNA levels and the response to anti-HER2 treatment in HER2-positive BC patients treated with adjuvant trastuzumab and show that this association is independent of estrogen receptor (ER) tumor positivity. While HER2 mRNA expression was significantly correlated with HER2 protein levels in ER-negative tumors, no correlation was found in ER-positive tumors, and HER2 protein expression was not associated with relapse risk. Correlation analyses in the ER-positive subset identified ER activity as the pathway inversely associated with HER2 mRNA. Associations between HER2 levels and oncogene addiction, as well as between HER2 activation and trastuzumab sensitivity, were also observed in vitro in HER2-positive BC cell lines. In ER-positive but not ER-negative BC cells, HER2 transcription was increased by reducing ligand-dependent ER activity or inducing ER degradation. Accordingly, HER2 mRNA levels in patients were found to be inversely correlated with blood levels of estradiol, the natural ligand of ER that induces ER activation. Moreover, low estradiol levels were associated with a lower risk of relapse in HER2-positive BC patients treated with adjuvant trastuzumab. Overall, we found that HER2 mRNA levels, but not protein levels, indicate the HER2 dependency of tumor cells and low estrogen-dependent ER activity in HER2-positive tumors.

Intrinsic subtypes and therapeutic decision-making in hormone receptor-positive/HER2-negative metastatic breast cancer with visceral crisis: A case report

BACKGROUND

CDK4/6 inhibitors (CDKi), namely, palbociclib, ribociclib, and abemaciclib, combined with either an aromatase inhibitor (AI) or fulvestrant are the standard first/second line for hormone receptor-positive(HR+)/HER2-negative(neg) metastatic breast cancer (MBC). However, the choice of one specific CDKi is arbitrary and based on the physician's experience with the drug, toxicity profile, and patient's preferences, whereas biomarkers for optimal patient selection have not been established so far. Moreover, upfront chemotherapy is still recommended in case of clinical presentation with visceral crisis, despite no evidence of superior benefit for chemotherapy regimens against CDKi-based regimens. Recent correlative biomarker analyses from pivotal trials of palbociclib and ribociclib showed that HR+/HER2-neg MBC might respond differently according to the molecular intrinsic subtype, with Luminal A and B tumors being sensitive to both CDKi, Basal-like being insensitive to endocrine therapy, irrespective of CDKi, and HER2-enriched tumors showing a benefit only with ribociclib-based therapy.

CLINICAL CASE

We hereby present a paradigmatic clinical case of a woman affected by a relapsed HR+/HER2-neg MBC with bone and nodal lesions, presenting with a visceral crisis in the form of lymphangitis carcinomatosis and diagnosed with a molecularly HER2-enriched tumor, successfully treated with upfront ribociclib + fulvestrant. The patient experienced a complete symptomatic and radiologic remission of the lymphangitis with a partial response as best response, according to RECIST 1.1 criteria. The progression-free survival (PFS) was of 20 months, in line with the median PFS observed in the ribociclib + fulvestrant pivotal trial, where, however, patients with visceral crisis had been excluded.

CONCLUSIONS

This clinical case confirms in the real-world setting that non-luminal subtypes can be found in HR+/HER2-neg disease and may have potential therapeutic implications in the metastatic setting. It also questions the recommendation of upfront chemotherapy in the case of a visceral crisis in the era of CDKi-based regimens. These issues merit further evaluation in prospective and larger studies.

HER2DX genomic test in HER2-positive/hormone receptor-positive breast cancer treated with neoadjuvant trastuzumab and pertuzumab: A correlative analysis from the PerELISA trial

Background

HER2DX is a prognostic and predictive assay in early-stage HER2-positive breast cancer based on clinical features and the expression of 4 gene signatures (immune, proliferation, luminal differentiation and HER2 amplicon), including ERBB2 mRNA levels. Here, we evaluated the ability of HER2DX to predict efficacy of a de-escalated, chemotherapy-free neoadjuvant regimen in HER2-positive/hormone receptor-positive breast cancer.

Methods

HER2DX was evaluated on pre-treatment tumour samples from the PerELISA phase II study focused on postmenopausal patients with operable HER2-positive/hormone receptor-positive breast cancer. Patients received 2-weeks of letrozole, and then underwent a re-biopsy for Ki67 evaluation. Patients with endocrine therapy sensitive disease (ESD) (i.e., >20.0% Ki67 relative reduction at week 2) continued letrozole and 5 cycles of trastuzumab and pertuzumab. Primary aim was to test the ability of HER2DX risk-score, HER2DX pCR score and HER2DX ERBB2 mRNA score (as continuous variables and group categories) to predict pathological complete response (pCR) in patients with ESD. Logistic regression and receiver–operator curve (ROC) analysis assessed associations of HER2DX scores with pCR and ESD.

Findings

HER2DX was evaluated in 55 patients (86.0%) enrolled in PerELISA and 40 patients (73.0%) had ESD. The pCR rate in patients with ESD was 22.5% (9/40). In this group, HER2DX pCR score and HER2DX ERBB2 mRNA score were significantly associated with pCR (p = 0.008 and p = 0.003, univariate logistic regression model; area under ROC [AUC] = 0.803 and 0.896). The pCR rate in low, medium, and high HER2DX pCR score groups was 7.7% (2/26), 46.2% (6/13) and 100.0% (1/1), respectively. The pCR rate in low, medium, and high HER2DX ERBB2 score groups was 0.0% (0/12), 7.7% (1/13) and 53.3% (8/15), respectively. HER2DX pCR score was also significantly associated with Ki-67 response following 2-weeks of letrozole (p = 0.002, univariate logistic regression model; AUC = 0.775). The rate of ESD in low, medium, and high HER2DX pCR score groups was 89.7% (26/29), 65.0% (13/20) and 16.7% (1/6), respectively.

Interpretation

HER2DX predicts response following neoadjuvant letrozole in combination with dual HER2 blockade with trastuzumab and pertuzumab in early-stage HER2-positive/hormone receptor-positive breast cancer.

Funding

This study received funding from Reveal Genomics.

The Transcriptomic Landscape of Pediatric Astrocytoma

Central nervous system tumors are the most common solid neoplasia during childhood and represent one of the leading causes of cancer-related mortality. Tumors arising from astrocytic cells (astrocytomas) are the most frequently diagnosed, and according to their histological and pathological characteristics, they are classified into four categories. However, an additional layer of molecular classification considering the DNA sequence of the tumorigenesis-associated genes IDH1/2 and H3F3A has recently been incorporated into the classification guidelines. Although mutations in H3F3A are found exclusively in a subtype of grade IV pediatric astrocytoma, mutations in IDH1/2 genes are very rare in children under 14 years of age. The transcriptomic profiles of astrocytoma in adults and children have been extensively studied. However, there is scarce information on these profiles in pediatric populations considering the status of tumorigenesis-associated genes. Therefore, here we report the transcriptomic landscape of the four grades of pediatric astrocytoma by RNA sequencing. We found several well-documented biological functions associated with the misregulated genes in the four grades of astrocytoma, as well as additional biological pathways. Among the four grades of astrocytoma, we found shared misregulated genes that could have implications in tumorigenesis. Finally, we identified a transcriptional signature for almost all grades of astrocytoma that could be used as a transcription-based identification method.

Characteristics and survival in bone metastatic breast cancer patients with different hormone receptor status: A population-based cohort study

Background

Accumulating preclinical evidence has uncovered the indispensable role of steroid hormone and their receptors, namely, estrogen receptor (ER) and progesterone receptor (PR), in the development of bone metastases in breast cancer. Limited data are available regarding the survival difference between different hormone receptor (HR) subgroups, and its prognostic significance is uncertain now. Such data are important for risk stratification and needed to formulate specialized regimen for bone metastatic breast cancer.

Methods

From the year of diagnosis 2010 to 2018, 554,585 breast cancer patients, among which are 19,439 with bone metastasis and 10,447 with bone-only metastasis, were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Kaplan–Meier survival analysis was performed to compare the survival difference between the different HR status subgroups. Univariate and multivariate Cox proportional hazard regression was used to validate the prognostic role of HR status and identify other prognostic factors in bone metastatic breast cancer.

Results

ER-positive/PR-positive breast cancer patients with bone metastasis showed the best breast cancer-specific survival (BCSS) and overall survival (OS) than those with other HR statuses, while single PR-positive bone metastatic breast cancers manifest similar survival with ER-negative/PR-negative ones. Adjusted Cox regression analysis demonstrated that patients with older age, male, black race, ILC, higher tumor grade, T3–T4, HER2-negative status, absence of surgery or adjuvant treatment, and HR status other than ER-positive/PR-positive tended to have worse outcomes. Further subgroup analysis based on HER2 status showed that within HER2-positive breast cancers, ER-positive/PR-positive ones still manifest better survival than the other three HR status subgroups, which are similar in survival outcomes.

Conclusion

Although collectively viewed as HR-positive breast cancers, certain distinctions exist between bone metastatic breast cancers with different HR statuses in survival outcome. Our findings indicate that despite metastasizing to the same location, the different survival rate is determined by the HR status of breast cancer. The selection and intensity of the regimen should consider HR status, and HER2 status occasionally, when treating bone metastatic breast cancer.

Molecular Subtyping of Invasive Breast Cancer Using a PAM50-Based Multigene Expression Test-Comparison with Molecular-Like Subtyping by Tumor Grade/Immunohistochemistry and Influence on Oncologist's Decision on Systemic Therapy in a Real-World Setting

In intermediate risk hormone receptor (HR) positive, HER2 negative breast cancer (BC), the decision regarding adjuvant chemotherapy might be facilitated by multigene expression tests. In all, 142 intermediate risk BCs were investigated using the PAM50-based multigene expression test Prosigna® in a prospective multicentric study. In 119/142 cases, Prosigna® molecular subtyping was compared with local and two central (C1 and C6) molecular-like subtypes relying on both immunohistochemistry (IHC; HRs, HER2, Ki-67) and IHC + tumor grade (IHC+G) subtyping. According to local IHC, 35.4% were Luminal A-like and 64.6% Luminal B-like subtypes (local IHC+G subtype: 31.9% Luminal A-like; 68.1% Luminal B-like). In contrast to local and C1 subtyping, C6 classified >2/3 of cases as Luminal A-like. Pairwise agreement between Prosigna® subtyping and molecular-like subtypes was fair to moderate depending on molecular-like subtyping method and center. The best agreement was observed between Prosigna® (53.8% Luminal A; 44.5% Luminal B) and C1 surrogate subtyping (Cohen’s kappa = 0.455). Adjuvant chemotherapy was suggested to 44.2% and 88.6% of Prosigna® Luminal A and Luminal B cases, respectively. Out of all Luminal A-like cases (locally IHC/IHC+G subtyping), adjuvant chemotherapy was recommended if Prosigna® testing classified as Prosigna® Luminal A at high / intermediate risk or upgraded to Prosigna® Luminal B.

Precision Medicine in Metastatic Colorectal Cancer: Targeting ERBB2 (HER-2) Oncogene

Simple Summary

Colorectal cancer (CRC) is the third most common cancer in terms of incidence rate in adults and the second most common cause of cancer-related death in Europe. The treatment of metastatic CRC (mCRC) is based on the use of chemotherapy, anti-vascular endothelial growth factor (VEGF), and anti-epidermal growth factor receptor (EGFR) for RAS wild-type tumors. Precision medicine tries to identify molecular alterations that could be treated with targeted therapies. Although ERBB2 (also known as HER-2) has an important therapeutic role in breast and esophagogastric cancer, there are no approved ERBB2-targeted therapies for mCRC. The purpose of this review is to describe the landscape of ERBB2-positive mCRC.

Abstract

Colorectal cancer (CRC) is the third most common cancer in terms of incidence rate in adults and the second most common cause of cancer-related death in Europe. The treatment of metastatic CRC (mCRC) is based on the use of chemotherapy, anti-vascular endothelial growth factor (VEGF), and anti-epidermal growth factor receptor (EGFR) for RAS wild-type tumors. Precision medicine tries to identify molecular alterations that could be treated with targeted therapies. ERBB2 amplification (also known as HER-2) has been identified in 2–3% of patients with mCRC, but there are currently no approved ERBB2-targeted therapies for mCRC. The purpose of this review is to describe the molecular structure of ERBB2, clinical features of these patients, diagnosis of ERBB2 alterations, and the most relevant clinical trials with ERBB2-targeted therapies in mCRC.

Targeted Therapeutic Options and Future Perspectives for HER2-Positive Breast Cancer

Simple Summary

The development of several antiHuman Epidermal Growth Factor Receptor 2 (HER2) treatments over the last few years has improved the landscape of HER2-positive breast cancer. Despite this, relapse is still the main issue in HER2-positive breast cancer. The reasons for therapeutic failure lie in the heterogeneity of the disease itself, as well as in the drug resistance mechanisms. In this review, we intended to understand the milestones that have had an impact on this disease up to their implementation in clinical practice. In addition, understanding the underlying molecular biology of HER2-positive disease is essential for the optimization and personalization of the different treatment options. For this reason, we focused on two relevant aspects, which are triple-positive disease and the role that modulation of the immune response might play in treatment and prognosis.

Abstract

Despite the improvement achieved by the introduction of HER2-targeted therapy, up to 25% of early human epidermal growth factor receptor 2-positive (HER2+) breast cancer (BC) patients will relapse. Beyond trastuzumab, other agents approved for early HER2+ BC include the monoclonal antibody pertuzumab, the antibody-drug conjugate (ADC) trastuzumab-emtansine (T-DM1) and the reversible HER2 inhibitor lapatinib. New agents, such as trastuzumab-deruxtecan or tucatinib in combination with capecitabine and trastuzumab, have also shown a significant improvement in the metastatic setting. Other therapeutic strategies to overcome treatment resistance have been explored in HER2+ BC, mainly in HER2+ that also overexpress estrogen receptors (ER+). In ER+ HER2+ patients, target therapies such as phosphoinositide-3-kinase (PI3K) pathway inhibition or cyclin-dependent kinases 4/6 blocking may be effective in controlling downstream of HER2 and many of the cellular pathways associated with resistance to HER2-targeted therapies. Multiple trials have explored these strategies with some promising results, and probably, in the next years conclusive results will succeed. In addition, HER2+ BC is known to be more immunogenic than other BC subgroups, with high variability between tumors. Different immunotherapeutic agents such as HER-2 therapy plus checkpoint inhibitors, or new vaccines approaches have been investigated in this setting, with promising but controversial results obtained to date.

High Mutation Burden in ER-Positive/HER2-Negative/Luminal Breast Cancers

Background: Tumor mutation burden (TMB) is arising as a useful marker of checkpoint inhibitors’ effectiveness in cancer patients in general and has been proposed as predictive in breast cancers. Despite the initial success of checkpoint inhibitors in triple-negative breast cancer, ER-positive breast cancers are less amenable to immunotherapy treatments due to the lower immunogenicity of this subset, associated with lower TMB and less pronounced inflammatory cell infiltration. However, a minority of ER-positive breast cancers do have a higher TMB and could be targets of immune checkpoint inhibitors. Methods: This investigation uses publicly available genomic data to examine ER-positive/HER2-negative or luminal breast cancers with high mutation numbers and compare them with cancers of the same subtype and low mutation numbers. Clinical characteristics and molecular correlates according to mutation numbers are described. Results: ER-positive/HER2-negative and luminal breast cancers with high mutation numbers have a higher prevalence of PIK3CA mutations and in some of the series examined mutations in TP53 and CDH1. A significant proportion of cancers with high mutation numbers carry mutations in microsatellite instability genes and genes involved in DNA damage response. Despite these differences, the prognosis of ER-positive/HER2-negative and luminal breast cancers with high mutation numbers is not significantly different compared to counterparts with lower mutation counts. Conclusions: These data may inform the potential suitability of these cancers for immunotherapy and could guide the development of rational combination therapies based on immune checkpoint inhibitors with other targeted drugs.

Impact of Human Epidermal Growth Factor Receptor 2 (HER2) Low Status in Response to Neoadjuvant Chemotherapy in Early Breast Cancer

Introduction In clinical practice, there is a binary distinction between human epidermal growth factor receptor 2 (HER2)-positive and HER2-negative (HER2-) breast cancer (BC). However, within HER2- disease, there is significant heterogeneity. Particularly, HER2- tumors that express some level of HER2 by immunohistochemistry (IHC) score 1+ or 2+/in situ hybridization (ISH) non-amplified are currently defined as HER2-low. This subgroup has shown distinct biological features compared to HER2-zero (HER2-0) BC and additionally novel antibody-drug conjugate therapies have demonstrated a potential and promising activity in HER2-low BC population. This study aims to evaluate the impact of HER2-low status in response to neoadjuvant chemotherapy (NACT) in HER2- BC being HER2-low and HER2-0 status. Materials and methods In a single institution, we retrospectively reviewed clinical and pathological data of HER2 early-stage BC patients treated with NACT following definitive surgery from January 2015 to December 2020. Tumors with HER2 IHC 0 were classified as HER2-0 and IHC score 1+ and 2+/ISH non-amplified as HER2-low. The primary objective was to evaluate the rate of pathological complete response (pCR) using the definition of ypT0/Tis ypN0 according to HER2-low and HER2-0 subgroups. Secondary objectives were to evaluate biological features between the two subgroups, disease-free survival (DFS), and overall survival (OS). Pearson chi-square, Fisher's exact, and Mann-Whitney tests were performed. The Kaplan-Meier method was used to plot DFS and OS curves. A p-value of <0.05 was considered statistically significant. Results A total of 72 patients with HER2 BC were included with a median age at diagnosis of 52.5 years and a median follow-up time of 35.5 months. Of patients, 56.9% had HER2-low disease and 43.1% had HER2-0 disease. Significant differences between the two subgroups were detected regarding hormonal receptor status and proliferation grade (Ki67). In the HER2-low subgroup, 70% of tumors were luminal-like and 64.5% of HER2-0 patients had triple-negative BC (p = 0.03). There were statistically significant differences regarding estrogen (p = 0.00) and progesterone (p = 0.02) receptors. The median Ki67 rate was higher in the HER2-0 subset (mean rank = 43.9) compared to HER2-low (mean rank = 30.9) and this difference was statistically significant (p = 0.00). HER2-low patients presented more stage III tumors (65.9%) and HER2-0 patients were mainly stage II (61.3%), and this was statistically relevant (p = 0.03). The prevalence of other clinical and pathological features was comparable between both groups. HER2-low subgroup achieved lower pCR rates (14.6% vs. 29.0%) but this difference was not statistically significant (p = 0.15). Similarly, there was no difference between the two subgroups regarding DFS (p = 0.97) and OS (p = 0.35), although the data were immature. Conclusion As in prior studies, this study did not support a significant impact of HER2-low status on response to NACT in HER2- patients with early-stage BC. HER2-low patients had a lower pCR, which may suggest a worse response to classic chemotherapy regimen and may have clinical implications that should be further exploited. The prevalence of hormonal receptors in HER2-low tumors was consistent with previous data in the literature. Although retrospective, the data suggest that HER2-low tumors should be regarded as a distinct biological subtype and more research is warranted.

HER2+ Breast Cancer Escalation and De-Escalation Trial Design: Potential Role of Intrinsic Subtyping

Simple Summary

Classical clinical research has been developed according to immunohistochemical breast cancer subtypes, instead of designing trials specifically for each molecular subtype. Efforts in de-escalating treatment should focus on identifying a subgroup of HER2 oncogene addicted tumours that are especially sensitive to anti-HER2 therapies and, thus, spare unnecessary treatments. A prognostic assay that integrates molecular tumour features with clinical and pathologic variables and accurately defines a group of HER2 addicted tumours remains the best candidate among these strategies.

Abstract

Long-term outcomes in breast cancer patients differ based on the molecular subtype, with HER2-E being the most aggressive one. Advances in clinical practice have dramatically shifted HER2+ breast cancer prognosis. Risk adapted strategies to individualize therapies are necessary. De-escalation approaches have been encouraged based on the risks of clinical-pathological factors. Molecular gene subtyping could further accurately define HER2 addicted tumours that are sensitive to anti-HER2 therapies, thus sparing unnecessary treatments. The transition from immunochemistry to molecular profiling in HER2+ breast cancer is discussed.

Biomarkers of everolimus efficacy in breast cancer therapy

OBJECTIVE

Everolimus is an inhibitor of serine/ threonine kinase mTOR. The drug is approved for the treatment of metastatic ER positive, HER2 negative breast cancers and benefits a subset of patients with these breast cancers in combination with hormonal therapies. Despite extensive efforts, no additional predictive biomarkers to guide therapeutic decisions for everolimus have been introduced in clinical practice.

DATA SOURCES

This paper discusses predictive biomarkers for everolimus efficacy in breast cancer. A search of the medline and web of science databases was performed using the words "everolimus" and "biomarkers". References of retrieved articles were manually scanned for additional relevant articles.

DATA SUMMARY

Everolimus benefits a subset of patients with metastatic ER positive, HER2 negative breast cancers in combination with hormonal therapies. Despite extensive efforts no additional predictive biomarkers to guide therapeutic decisions for everolimus therapy have been confirmed for use in clinical practice. However, promising biomarker leads for everolimus efficacy in breast cancer have been suggested and include expression of proteins in the mTOR pathway in ER positive, HER2 negative breast cancers. In HER2 positive cancers PIK3CA mutations, and PTEN expression loss are prognostic. Other clinical predictive biomarkers with more limited data include characteristics derived from whole genome sequencing, subsets of circulating leukocytes and changes in Standardized Uptake Values (SUV) of Positron Emission Tomography (PET) scans.

CONCLUSIONS

Putative predictive biomarkers for everolimus efficacy in breast cancer patients, both genomic and clinical, deserve further study and could lead to a better selection of responsive patients.

Development and validation of the new HER2DX assay for predicting pathological response and survival outcome in early-stage HER2-positive breast cancer

Background

Both clinical and genomic data independently predict survival and treatment response in early-stage HER2-positive breast cancer. Here we present the development and validation of a new HER2DX risk score, and a new HER2DX pathological complete response (pCR) score, both based on a 27-gene expression plus clinical feature-based classifier.

Methods

HER2DX is a supervised learning algorithm incorporating tumour size, nodal staging, and 4 gene expression signatures tracking immune infiltration, tumour cell proliferation, luminal differentiation, and the expression of the HER2 amplicon, into a single score. 434 HER2-positive tumours from the Short-HER trial were used to train a prognostic risk model; 268 cases from an independent cohort were used to verify the accuracy of the HER2DX risk score. In addition, 116 cases treated with neoadjuvant anti-HER2-based chemotherapy were used to train a predictive model of pathological complete response (pCR); two independent cohorts of 91 and 67 cases were used to verify the accuracy of the HER2DX pCR likelihood score. Five publicly available independent datasets with >1,000 patients with early-stage HER2-positive disease were also analysed.

Findings

In Short-HER, HER2DX variables were associated with good risk outcomes (i.e., immune, and luminal) and poor risk outcomes (i.e., proliferation, and tumour and nodal staging). In an independent cohort, continuous HER2DX risk score was significantly associated with disease-free survival (DFS) (p=0·002); the 5-year DFS in the low-risk group was 97·4% (94·4-100·0%). For the neoadjuvant pCR predictor training cohort, HER2DX variables were associated with pCR (i.e., immune, proliferation and HER2 amplicon) and non-pCR (i.e., luminal, and tumour and nodal staging). In both independent test set cohorts, continuous HER2DX pCR likelihood score was significantly associated with pCR (p<0·0001). A weak negative correlation was found between the HER2DX risk score versus the pCR score (correlation coefficient -0·19).

Interpretation

The two HER2DX tests provide accurate estimates of the risk of recurrence, and the likelihood to achieve a pCR, in early-stage HER2-positive breast cancer.

Funding

This study received funding from Reveal Genomics, IDIBAPS and the University of Padova.

Plant Derived Bioactive Compounds, Their Anti-Cancer Effects and In Silico Approaches as an Alternative Target Treatment Strategy for Breast Cancer: An Updated Overview

Cancer is one of the most common malignant diseases that occur worldwide, among which breast cancer is the second leading cause of death in women. The subtypes are associated with differences in the outcome and were selected for treatments according to the estrogen receptor, progesterone receptor, and human epidermal growth factor receptor. Triple-negative breast cancer, one of the subtypes of breast cancer, is difficult to treat and can even lead to death. If breast cancer is not treated during the initial stages, it may spread to nearby organs, a process called metastasis, through the blood or lymph system. For in vitro studies, MCF-7, MDA-MB-231, MDA-MB-468, and T47B are the most commonly used breast cancer cell lines. Clinically, chemotherapy and radiotherapy are usually expensive and can also cause side effects. To overcome these issues, medicinal plants could be the best alternative for chemotherapeutic drugs with fewer side effects and cost-effectiveness. Furthermore, the genes involved in breast cancer can be regulated and synergized with signaling molecules to suppress the proliferation of breast cancer cells. In addition, nanoparticles encapsulating (nano-encapsulation) medicinal plant extracts showed a significant reduction in the apoptotic and cytotoxic activities of breast cancer cells. This present review mainly speculates an overview of the native medicinal plant derived anti-cancerous compounds with its efficiency, types and pathways involved in breast cancer along with its genes, the mechanism of breast cancer brain metastasis, chemoresistivity and its mechanism, bioinformatics approaches which could be an effective alternative for drug discovery.