Evaluation of Clinical Outcomes According to HER2 Detection by Fluorescence In Situ Hybridization in Women with Metastatic Breast Cancer Treated with Trastuzumab

In ER-Positive, HER2-Negative Breast Cancers, HER2 mRNA Levels Correlate Better with Clinicopathologic Features and Oncotype DX Recurrence Score than HER2 Immunohistochemistry

With the approval of trastuzumab deruxtecan for treating advanced human epidermal growth factor receptor-2 (HER2) low breast cancer (BC), it has become increasingly important to develop more accurate and reliable methods to identify HER2-low BC. In addition, HER2 immunohistochemistry (IHC) has limitations for quantification of HER2. We explored the relationship between HER2 IHC and mRNA levels and evaluated whether HER2 IHC scores and mRNA levels are associated with clinicopathologic features and Oncotype DX Recurrence Score (RS) in estrogen receptor (ER)-positive, HER2-negative BCs. A total of 750 BCs sent for Oncotype DX (ODX) testing were included in this study, and 559 with HER2 mRNA levels were available. There were no statistically significant differences between HER2 0 and HER2-low BC in clinicopathologic variables or ODX RS using HER2 IHC. There was a significant difference in median HER2 mRNA values between HER2 0 and HER2-low (8.7 vs 9.3, P < .001); however, the HER2 mRNA distribution had substantial overlap between these 2 groups with a suboptimal area under the receiver operating characteristic curve (area under the receiver operating characteristic curve = 0.68). A HER2 mRNA value of 9.2 was generated as the optimal cutoff for distinguishing HER2 0 and HER2-low BC. Comparing ER+ BCs with HER2 mRNA high (>9.2) and low (≤9.2) revealed a statistically significant difference in most clinicopathologic variables and ODX RS. From this large cohort of ER-positive, HER2-negative BC, our results demonstrated that HER2 mRNA levels correlated better with clinicopathologic features and recurrence risk as assessed by ODX RS than HER2 IHC scores. Our findings suggest that HER2 mRNA-detecting methods could potentially serve as a quantitative and reliable method for identifying a biologically meaningful group of HER2-low BC. Further study is needed to determine whether HER2 mRNA levels could be more reliable than IHC for identifying which patients will be most likely to benefit from trastuzumab deruxtecan.

Clinicopathological characteristics and value of HER2-low expression evolution in breast cancer receiving neoadjuvant chemotherapy

OBJECTIVE

The present study aimed to evaluate the clinicopathological characteristics and value of HER2-low expression evolution in breast cancer receiving neoadjuvant chemotherapy (NAC).

METHODS

Patients with HER2 negative breast cancer receiving NAC from January 2017 to December 2020 were enrolled in this study. The clinicopathological characteristics, response to NAC, evolution of HER2 and prognostic value were retrospectively analyzed.

RESULTS

410 patients were included. The proportion of HR positive disease in HER2-low cases was higher than in HER2-zero population (75.8 % vs. 65.8 %, P = 0.040). No statistical significant difference in pCR rate was observed between HER2-low and HER2-zero patients (33.8 % vs. 39.3 %, P = 0.290) when pCR was defined as ypTis/0ypN0. Exploratory analysis revealed that the pCR rate of HER2-low cases was significantly lower than HER2-zero patients in the entire population (19.8 % vs. 33.3 %, P = 0.004) and HR positive population (12.6 % vs. 29.9 %, P = 0.001) when pCR was defined as ypT0ypN0. The evolution rate of HER2 expression after NAC was 31.0 % in HER2-zero patients and 24.7 % in HER2-low patients. Compared with patients with HR positive disease, patients with TNBC had higher evolution rate of HER2 expression after NAC (37.7 % vs. 23.6 %). Significant association was observed between HER2 evolution with histology type and Ki-67 index in HER2-zero patients and with lymph node involvement, HR status and Ki-67 index in HER2-low patients. Prognostic impact of HER2 evolution was not observed.

CONCLUSIONS

HR positive and HR negative HER2-low breast cancer exhibit different clinicopathological features, response to NAC and HER2 evolution after treatment.

Label-free electrochemical cancer cell detection leveraging hemoglobin-encapsulated silver nanoclusters and Cu-MOF nanohybrids on a graphene-assisted dual-modal probe

Breast cancer detection at an early stage significantly increases the chances of successful treatment and survival. This study presents an electrochemical biosensor for detecting breast cancer cells, utilizing silver nanoclusters encapsulated by hemoglobin and Cu (II)-porphyrin-metal organic framework (BioMOF) in a graphene-incorporated nanohybrid probe. This Hb-AgNCs@MOF-G probe demonstrates high electrochemical activity, superior dispersity, porosity, and a large surface area for effective functionalization. Using a green ultrasonic-assisted stirring method, we fabricate ultra-small 5 nm particles that readily immobilize on a glassy carbon electrode, generating a detection signal when interacting with ferricyanide/ferrocyanide redox probes. The resulting immunosensor detects as few as 2 cells/mL using Electrochemical Impedance Spectroscopy (EIS) "signal on" and 16 cells/mL via Square Wave Voltammetry (SWV) "signal off", within a broad range of cell concentrations (102-5 × 104 cells/mL). Our designed sensor shows improved selectivity (5- to 16-fold) and robust detection in human blood with a recovery efficiency between 94.8-106% (EIS method) and 95.4-111% (SWV method). This sensor could streamline early cancer diagnosis and monitor patient treatment without requiring labelling or signal amplification. As a pioneering endeavor, we've utilized integrated porous MOFs with Hb-encapsulated silver nanoclusters in cancer detection, where these components collectively enhance the overall functionality.

Employing Pd nanoparticles decorated on halloysite nanotube/carbon composite for electrochemical aptasensing of HER2 in breast cancer patients

An effective biosensing platform is described based on halloysite nanotube/carbon composite decorated with Pd nanoparticles (HNT/C@Pd NPs). A novel electrochemical aptasensor was designed using the proposed nano-platform to determine human epidermal growth factor receptor 2 (HER2), a breast cancer biomarker. Inherently, aptasensing interfaces provide high sensitivity and selectivity for tumor markers owing to the high specific surface area of HNT/C and good conductivity stems from deposition of Pd NPs into HNT/C composite. With a correlation coefficient of 0.996, the electrochemical aptasensor demonstrated a wide linear range from 0.03 ng/mL to 9 ng/mL. The limit of detection (LOD) of the established assay was 8 pg/mL based on S/N = 3 method. Further, the designed biosensor demonstrated acceptable selectivity, good reproducibility, and high stability. The applicability of the impedimetric sensor in human serum samples was also examined and compared to enzyme-linked immunosorbent assay (ELISA) assay (p-value >0.05). Based on the results, it was found that the proposed methodology can be used in quantification of breast cancer markers for early diagnosis and treatment.

Novel RICTOR amplification harbouring entities: FISH validation of RICTOR amplification in tumour tissue after next-generation sequencing

Alterations in mTOR signalling molecules, including RICTOR amplification, have been previously described in many cancers, particularly associated with poor prognosis. In this study, RICTOR copy number variation (CNV) results of diagnostic next-generation sequencing (NGS) were analysed in 420 various human malignant tissues. RICTOR amplification was tested by Droplet Digital PCR (ddPCR) and validated using the "gold standard" fluorescence in situ hybridisation (FISH). Additionally, the consequences of Rictor protein expression were also studied by immunohistochemistry. RICTOR amplification was presumed in 37 cases with CNV ≥ 3 by NGS, among these, 16 cases (16/420; 3.8%) could be validated by FISH, however, ddPCR confirmed only 11 RICTOR-amplified cases with lower sensitivity. Based on these, neither NGS nor ddPCR could replace traditional FISH in proof of RICTOR amplification. However, NGS could be beneficial to highlight potential RICTOR-amplified cases. The obtained results of the 14 different tumour types with FISH-validated RICTOR amplification demonstrate the importance of RICTOR amplification in a broad spectrum of tumours. The newly described RICTOR-amplified entities could initiate further collaborative studies with larger cohorts to analyse the prevalence of RICTOR amplification in rare diseases. Finally, our and further work could help to improve and expand future therapeutic opportunities for mTOR-targeted therapies.

Differential response of HER2-positive breast cancer to anti-HER2 therapy based on HER2 protein expression level

BACKGROUND

Increasing data indicate that HER2-positive (HER2 + ) breast cancer (BC) subtypes exhibit differential responses to targeted anti-HER2 therapy. This study aims to investigate these differences and the potential underlying molecular mechanisms.

METHODS

A large cohort of BC patients (n = 7390) was utilised. The clinicopathological characteristics and differential gene expression (DGE) of HER2+ immunohistochemical (IHC) subtypes, specifically HER2 IHC 3+ and IHC 2 + /Amplified, were assessed and correlated with pathological complete response (pCR) and survival in the neoadjuvant and adjuvant settings, respectively. The role of oestrogen receptor (ER) status was also investigated.

RESULTS

Compared to HER2 IHC 3+ tumours, BC patients with IHC 2 + /Amplified showed a significantly lower pCR rate (22% versus 57%, P < 0.001), shorter survival regardless of HER2 gene copy number, were less classified as HER2 enriched, and enriched for trastuzumab resistance and ER signalling pathway genes. ER positivity significantly decreased response to anti-HER2 therapy in IHC 2 + /Amplified, but not in IHC 3 + BC patients.

CONCLUSION

In HER2 + BC, overexpression of HER2 protein is the driver of the oncogenic pathway, and it is the main predictor of response to anti-HER2 therapy. ER signalling pathways are more dominant in BC with equivocal HER2 expression. personalised anti-HER2 therapy based on IHC classes should be considered.

History and Future of HER2-Targeted Therapy for Advanced Gastric Cancer

Human epidermal growth factor receptor 2 (HER2) is a receptor tyrosine kinase that belongs to the human epidermal growth factor receptor family. It is overexpressed/amplified in approximately 20% of gastric or gastroesophageal junction cancers. HER2 is being developed as a therapeutic target in a variety of cancers, and several agents have been shown to be effective in breast cancer. The development of HER2-targeted therapy for gastric cancer successfully began with trastuzumab. However, while effective in breast cancer, the successive anti-HER2 agents lapatinib, T-DM1, and pertuzumab failed to demonstrate benefits regarding survival in gastric cancer compared with the existing standard therapies. Intrinsic differences lie between gastric and breast cancer in terms of HER2-positive tumor biology, which may make development difficult. Recently, a novel anti-HER2 agent, trastuzumab deruxtecan, was introduced, and the development of HER2-positive gastric cancer agents has been moving to the next stage. This review summarizes the current HER2-targeted therapy for gastric or gastroesophageal cancer in chronological order and describes the promising future of HER2-targeted therapy.

HER2 Low Breast Cancer: A New Subtype or a Trojan for Cytotoxic Drug Delivery?

Despite the great progress made in the understanding of the biological behavior of certain types of invasive breast cancer, there is still no single histological or molecular classification that encompasses such diversity and accurately predicts the clinical course of distinct breast cancer subtypes. The long-lasting classification of breast cancer as HER2-positive vs. HER2-negative has recently come into question with the discovery of new antibody drug conjugates (ADC), which are proven to be remarkably efficient in treating HER2-low breast cancer. The HER2-low paradigm has challenged the traditional understanding of HER2 overexpression and emphasized the need for more robust HER2 testing in order to encompass HER2 intratumoral heterogeneity and spatial distribution more accurately. It is yet to be seen if low HER2 will remain merely a marker of HER2-equipped tumors targetable with ADCs or if distinctive molecular and phenotypic groups within HER2-low tumors will eventually be discerned.

Starring Role of Biomarkers and Anticancer Agents as a Major Driver in Precision Medicine of Cancer Therapy

Precision medicine is the most modern contemporary medicine approach today, based on great amount of data on people's health, individual characteristics, and life circumstances, and employs the most effective ways to prevent and cure diseases. Precision medicine in cancer is the most precise and viable treatment for every cancer patient based on the disease's genetic profile. Precision medicine changes the standard one size fits all medication model, which focuses on average responses to care. Consolidating modern methodologies for streamlining and checking anticancer drugs can have long-term effects on understanding the results. Precision medicine can help explicit anticancer treatments using various drugs and even in discovery, thus becoming the paradigm of future cancer medicine. Cancer biomarkers are significant in precision medicine, and findings of different biomarkers make this field more promising and challenging. Naturally, genetic instability and the collection of extra changes in malignant growth cells are ways cancer cells adapt and survive in a hostile environment, for example, one made by these treatment modalities. Precision medicine centers on recognizing the best treatment for individual patients, dependent on their malignant growth and genetic characterization. This new era of genomics progressively referred to as precision medicine, has ignited a new episode in the relationship between genomics and anticancer drug development.

HER2-low breast cancer: Novel detections and treatment advances

Breast cancer (BC), which has the highest cancer incidence in women, seriously threatens women's health. Since human epidermal growth factor receptor-2 (HER2) characterization, breast cancer treatment has entered an era of individualized targeted therapy. With the emergence of anti-HER2 targeting agents, monoclonal antibodies (mAbs) and tyrosine kinase inhibitors have considerably improved the prognosis of HER2-positive BC. However, HER2-low BC, accounting for 45-55% of BC patients, is less likely to benefit from conventional HER2-targeting mAbs. The growing success of the new generation of drugs, especially promising HER2-directed antibody-drug conjugates, has changed the treatment landscape for patients with HER2-low BC, leading to a research boom. HER-2-low BC is a heterogeneous entity, and there many areas remain to be explored. In this article, we review the literature on HER2-low BC, mainly focusing on its detection assays, clinicopathological profiles and treatment landscape, and hopefully provide insight into future perspectives.

Comparison of clinicopathological characteristics and response to neoadjuvant chemotherapy between HER2-low and HER2-zero breast cancer

Novel anti-HER2 antibody-drug conjugates trastuzumab deruxtecan (DS-8201a) showed its effect in previously-treated HER2-low metastatic breast cancer, suggesting a promising future in HER2-low breast cancer. We retrospectively reviewed the clinicopathological data of 325 patients with stage I-III HER2 negative breast cancer who received neoadjuvant chemotherapy in the First Affiliated Hospital of Sun Yat-sen University from January 2016 to June 2021. In general, 91 patients (28.0%) were HER2-zero, and 234 patients (72.0%) were HER2-low. The pathological complete response (pCR) rate of the entire cohort was 17.3%. The pCR rate was 16.7% in HER2-low group, and 18.9% in HER2-zero group, showing no significant difference. Patients with HER2-low tumors had significantly longer overall survival (OS) than patients with HER2-zero tumors. ER status was the affecting factor of OS in HER2-low patients in both univariate and multivariate analysis. In conclusion, evidence for HER2-low BC as a distinct entity is insufficient, and more efforts are needed to standardize the scoring of HER2-low breast cancer.

Morphology-Tuned Electrochemical Immunosensing of a Breast Cancer Biomarker Using Hierarchical Palladium Nanostructured Interfaces

Metallic nanostructures are considered attractive candidates for designing novel biosensors due to their enormously significant surface area, accelerated kinetics, and improved affinity. Controllable morphological tuning of metallic nanostructures on sensing interfaces is crucial for attaining clinically relevant sensitivity and exquisite selectivity in a complex biological environment. Therefore, a facile, convenient, and robust one-step electroreduction method was employed to develop different morphological variants of palladium (Pd) nanostructures supported onto oxidized carbon nanotubes to facilitate label-free electrochemical immunosensing of HER2. The morphological and structural attributes of the synthesized Pd nanostructures were thoroughly investigated using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and atomic force microscopy techniques. In-depth electrochemical investigations revealed an intimate correlation between the nanostructured sensor and electrochemical response, suggesting the suitability of hierarchical palladium nanostructures supported onto carbon nanotubes [Pd(-0.1 V)/CNT] for sensitive detection of HER2. The high surface area of hierarchical Pd nanostructures enabled an ultrasensitive electrochemical response toward HER2 (detection limit: 1 ng/mL) with a wide detection range of 10 to 100 ng/mL. The ease of surface modification, sensitivity, and reliable electrochemical response in human plasma samples suggested the enormous potential of Pd nanostructuring for chip-level point-of-care screening of HER2-positive breast cancer patients.

Cost-Effective Fiber Optic Solutions for Biosensing

In the last years, optical fiber sensors have proven to be a reliable and versatile biosensing tool. Optical fiber biosensors (OFBs) are analytical devices that use optical fibers as transducers, with the advantages of being easily coated and biofunctionalized, allowing the monitorization of all functionalization and detection in real-time, as well as being small in size and geometrically flexible, thus allowing device miniaturization and portability for point-of-care (POC) testing. Knowing the potential of such biosensing tools, this paper reviews the reported OFBs which are, at the moment, the most cost-effective. Different fiber configurations are highlighted, namely, end-face reflected, unclad, D- and U-shaped, tips, ball resonators, tapered, light-diffusing, and specialty fibers. Packaging techniques to enhance OFBs' application in the medical field, namely for implementing in subcutaneous, percutaneous, and endoscopic operations as well as in wearable structures, are presented and discussed. Interrogation approaches of OFBs using smartphones' hardware are a great way to obtain cost-effective sensing approaches. In this review paper, different architectures of such interrogation methods and their respective applications are presented. Finally, the application of OFBs in monitoring three crucial fields of human life and wellbeing are reported: detection of cancer biomarkers, detection of cardiovascular biomarkers, and environmental monitoring.

HER2-low breast cancers: Current insights and future directions

In light of the significant clinical benefits of novel HER2-targeting antibody-drug conjugates in advanced HER2-low expressing breast cancers in recent phases I and III clinical trials, particularly trastuzumab-deruxtecan (T-Dxd), the new "HER2-low" category in breast cancers (breast cancer with a HER2 IHC score of 1+, or 2+ without gene amplification) has gained increasing attention. In the past year, "HER2-low" breast cancers have been under active investigation by both oncologists and pathologists. In this current review, we update the recent cutting-edge research on HER2-low breast cancers, with a focus on the biology of HER2-low breast cancers, the issues on the identification of HER2-low breast cancers by immunohistochemistry in current practice of pathology, and the future directions in this emerging category in breast cancers.

Optical Microfiber with a Gold Nanorods-Black Phosphorous Nanointerface: An Ultrasensitive Biosensor and Nanotherapy Platform

The detection and therapy of cancers in the early stage significantly alleviate the associated dangers. Optical devices offer new opportunities for these early measures. However, the clinical translation of the existing methods is severely hindered by their relatively low sensitivity or unclear physiological metabolism. Here, an optical microfiber sensor with a drug loading gold nanorod-black phosphorous nanointerface, as an ultrasensitive biosensor and nanotherapy platform, is developed to meet the early-stage requirement. With interface sensitization and functionalization of the hybrid nanointerface, the microfiber sensor presents an ultrahigh sensing performance, achieving the selective detection of the HER2 biomarker with limits of detection of 0.66 aM in buffer solution and 0.77 aM in 10% serum. It can also distinguish breast cancer cells from other cells in the early stage. Additionally, enabled by the interface, the optical microfiber is able to realize cellular nanotherapy, including photothermal/chemotherapy with pump laser coupling after diagnosis, and evaluate therapy results in real time. The immobilization of the interface on the optical microfiber surface prevents the damage to normal cells induced by nanomaterial enrichment, making the device more efficient and intelligent. This study opens up a new avenue for the development of smart optical platforms for sensitive biosensing and precision therapy.

HER2-low status and response to neoadjuvant chemotherapy in HER2 negative early breast cancer

PURPOSE

Knowledge on whether low expressions of HER2 have prognostic impact in early-stage breast cancer (BC) and on its response to current chemotherapy protocols can contribute to medical practice and development of new drugs for this subset of patients, changing treatment paradigms. This study aims to evaluate the impact of HER2-low status on response to neoadjuvant chemotherapy (NACT) and survival outcomes in early-stage HER2-negative BC.

METHODS

Records from all BC patients treated with NACT from January 2007 to December 2018 in a single cancer center were retrospectively reviewed. HER2-negative (immunohistochemistry [IHC] 0, + 1, or + 2 non-amplified by in situ hybridization [ISH]) patients were included. HER2-low was defined by IHC + 1 or + 2 ISH non-amplified and HER2-0 by IHC 0. The coprimary objectives were to compare pathological complete response (pCR) and relapse-free survival (RFS) between luminal/HER2-low versus luminal/HER2-0 populations and between triple negative (TNBC)/HER2-low versus TNBC/HER2-0.

RESULTS

In total, 855 HER2-negative patients were identified. The median follow-up was 59 months. 542 patients had luminal subtype (63.4%) and 313 had TNBC (36.6%). 285 (33.3%) were HER2-low. Among luminal patients, 145 had HER2 IHC + 1 (26.8%) and 91 had IHC + 2/ISH non-amplified (16.8%). In TNBC, 36 had HER2 IHC + 1 (11.5%) and 13 had IHC + 2/ISH non-amplified (4.2%). Most patients had locally advanced tumors, regardless of subtype or HER2-low status. For luminal disease, pCR was achieved in 13% of HER2-low tumors versus 9.5% of HER2-0 (p = 0.27). Similarly, there was no difference in pCR rates among TNBC: 51% versus 47% in HER2-low versus HER2-0, respectively (p = 0.64). HER2-low was also not prognostic for RFS, with 5-year RFS rates of 72.1% versus 71.7% (p = 0.47) for luminal HER2-low/HER2-0, respectively, and 75.6% versus 70.8% (p = 0.23) for TNBC HER2-low/HER2-0.

CONCLUSION

Our data does not support HER2-low as a biologically distinct BC subtype, with no prognostic value on survival outcomes and no predictive effect for pCR after conventional NACT.

Milestones of Precision Medicine: An Innovative, Multidisciplinary Overview

Although the concept of precision medicine, in which healthcare is tailored to the molecular and clinical characteristics of each individual, is not new, its implementation in clinical practice has been heterogenous. In some medical specialties, precision medicine has gone from being just a promise to a reality that achieves better patient outcomes. This is a fact if we consider, for example, the great advances made in the genetic diagnosis and subsequent treatment of countless hereditary diseases, such as cystic fibrosis, which have improved the life expectancy of many of the affected children. In the field of oncology, the development of targeted therapies has prolonged the survival of patients with breast, lung, colorectal, melanoma, and hematological malignancies. In other disciplines, clinical milestones are perhaps less well known, but no less important. The current challenge is to expand and generalize the use of technologies that are central to precision medicine, such as massively parallel sequencing, to improve the management (prevention and treatment) of complex conditions such as cardiovascular, kidney, or autoimmune diseases. This process requires investment in specialized expertise, multidisciplinary collaboration, and the nationwide organization of genetic laboratories for diagnosis of specific diseases.

Antibody-Drug Conjugates for the Treatment of Breast Cancer

Metastatic breast cancer (BC) is currently an incurable disease. Besides endocrine therapy and targeted agents, chemotherapy is often used in the treatment of this disease. However, lack of tumor specificity and toxicity associated with dose exposure limit the manageability of cytotoxic agents. Antibody-drug conjugates (ADCs) are a relatively new class of anticancer drugs. By merging the selectivity of monoclonal antibodies with the cytotoxic properties of chemotherapy, they improve the therapeutic index of antineoplastic agents. Three core components characterize ADCs: the antibody, directed to a target antigen; the payload, typically a cytotoxic agent; a linker, connecting the antibody to the payload. The most studied target antigen is HER2 with some agents, such as trastuzumab deruxtecan, showing activity not only in HER2-positive, but also in HER2-low BC patients, possibly due to a bystander effect. This property to provide a cytotoxic impact also against off-target cancer cells may overcome the intratumoral heterogeneity of some target antigens. Other cancer-associated antigens represent a strategy for the development of ADCs against triple-negative BC, as shown by the recent approval of sacituzumab govitecan. In this review, we discuss the current landscape of ADC development for the treatment of BC, as well as the possible limitations of this treatment.

The Exciting New Field of HER2-Low Breast Cancer Treatment

Since human epidermal growth factor receptor-2 (HER2) characterization, going through clinical research and regulatory approval of HER2-targeted therapies, much has elapsed and is still unfolding. Hitherto, only breast cancer (BC) patients with HER2 immunohistochemistry 3+ or with HER2 gene fluorescence in-situ hybridization (FISH) amplification (a.k.a., HER2-positive BC) have benefited from anti-HER2 agents. In recent years, however, much of the research effort has been expanded, with positive outcomes being reached for formerly known HER2-negative BC that yet express HER2 to some degree (HER2 immunohistochemistry 1+ or 2+, but FISH negative) and are currently being classified as HER2-low BC for the purpose of trial enrollment. In this sense, our aim is to review the body of evidence of HER2-low BC that led to the study of first-generation anti-HER2 agents, like trastuzumab, and how they have failed to achieve any clinical applicability in this setting. In addition, we review new data that is leading to the growing success of the new generation of drugs, especially the promising HER2-directed antibody-drug conjugates. A narrative review is also performed regarding the rationale behind the consolidated and ongoing clinical trials studying anti-HER2 agents in combination with unrelated agents, such as immunotherapy, endocrine therapy, and CDK4/6 inhibitors. Hopefully, all this ongoing research effort will be able to extend the survival benefits seen with anti-HER2 agents in HER2-positive disease, at least to some degree, to the greater proportion of patients with HER2-low BC.

Survey of low ER-positive expression and its correlation with other clinical and pathological factors in breast cancer

Introduction

Breast cancer is the most common cancer in women. Owning to the prominent role of biomarkers in molecular classification of breast cancer in recent years, evaluation of estrogen receptor (ER), progesterone receptor (PR), and Her2/neu seems to be required for prognosis and treatment of patients.

Material and Methods

One-hundred twenty two patients with primary breast carcinoma were selected and immunohistochemistry staining for ER, PR, and Her2/neu were performed on representative paraffin blocks. ER level can be semi-quantified by immunohistochemistry using the H-score. The score, given as the sum of the percent of tumor cells staining multiplied by the intensity level, ranges from 0 to 300 as low, intermediate, and high grades. The statistical association of ER expression with the level of PR and Her2/neu, tumor size, necrosis, microscopic grade, vascular invasion, and lymph node involvement were analyzed using SPSS16 software.

Results

Results showed that among 122 studied patients, 44.3% were in the low ER-positive group where most of these cases (22.1%) were Her2/neu negative. Although there was a reciprocal interplay between the expression of ER and Her2/neu, increased expression of ER had a direct relation with PR level. However, there was no statistical relation between ER level with age, tumor size, necrosis, microscopic grade, vascular invasion, and lymph node involvement.

Discussion

The study clearly indicated that low ER group encompasses the high frequency of breast cancer patients. Furthermore, the most cases of low ER patients were in Her2/neu negative group.

Differential prognostic value of positive HER2 status determined by immunohistochemistry or fluorescence in situ hybridization in breast cancer

PURPOSE

Human epidermal growth factor-receptor-2 (HER2) is a membrane-tyrosine-kinase that is amplified/overexpressed up to 20% in breast cancer. HER2 positive status is associated with faster disease progression, higher metastatic potential, and shorter disease-free/overall survival and also has emerged as an important therapeutic target in breast cancer. HER2 status can be determined by in-situ-hybridization (ISH) or immunohistochemistry (IHC). Although the concordance rate between ISH and IHC is well-known, the prognostic power of both technologies if tested in parallel on the same tumor has not been studied extensively.

METHODS

In this study we retrospectively analyzed a large HER2 positive breast cancer cohort tested both with fluorescence labeled ISH (FISH) and IHC in parallel on each case. We stratified HER2 positive results by FISH and IHC with long-term overall survival, 5-year survival and metastases/recurrence rates. Positive HER2 status both FISH and IHC was available in 364 patients.

RESULTS

The number of HER2 FISH-positive and FISH-negative patients was 342 and 22, respectively. The number of HER2 IHC 0/1 + , IHC 2 + , and IHC 3 + patients was 12, 42, and 310, respectively. Among the patients with IHC 3 + status, 288 were FISH-positive and 22 FISH-negative. HER2 status determined by FISH correlated with clinical outcomes (overall survival and with metastases/recurrence, p = 0.036, p = 0.039), whereas HER2 status determined by IHC did not.

CONCLUSION

Our results indicate that prognostic information in HER2 positive breast cancer also depends on the methodology of how positivity was determined. In our cohort, FISH was superior to IHC based positive HER2 status.

The emerging role of antibody-drug conjugates in urothelial carcinoma

INTRODUCTION

In December 2019, the US Food and Drug Administration granted accelerated approval to the novel nectin-4-targeting antibody-drug conjugate, enfortumab vedotin, for the treatment of platinum-refractory and immune checkpoint blockade-refractory locally advanced or metastatic urothelial carcinoma. Antibody-drug conjugates represent a new therapeutic modality in urothelial cancer; and beyond nectin-4, agents targeting Trop-2, HER2, and EpCAM are also in clinical development.

AREAS COVERED

This review outlines the biologic rationale and the clinical development of novel antibody-drug conjugates for the treatment of urothelial cancer across the spectrum of disease from non-muscle-invasive bladder cancer through treatment-refractory metastatic disease.

EXPERT OPINION

The high response rates observed with enfortumab vedotin - both as monotherapy and in combination with checkpoint blockade immunotherapy - suggest this and other antibody-drug conjugates may have efficacy similar to or even exceeding that of traditional cytotoxic chemotherapy. Ongoing clinical development of antibody-drug conjugates in urothelial cancer will address the optimal combination or sequencing strategy with anti-PD-1/L1 immunotherapy and platinum-based chemotherapy.

Current and Future Treatment Strategies for Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children, and can be subcategorized histologically and/or based on PAX-FOXO1 fusion gene status. Over the last four decades, there have been no significant improvements in clinical outcomes for advanced and metastatic RMS patients, underscoring a need for new treatment options for these groups. Despite significant advancements in our understanding of the genomic landscape and underlying biological mechanisms governing RMS that have informed the identification of novel therapeutic targets, development of these therapies in clinical trials has lagged far behind. In this review, we summarize the current frontline multi-modality therapy for RMS according to pediatric protocols, highlight emerging targeted therapies and immunotherapies identified by preclinical studies, and discuss early clinical trial data and the implications they hold for future clinical development.

Assessment of ERBB2/HER2 Status in HER2-Equivocal Breast Cancers by FISH and 2013/2014 ASCO-CAP Guidelines

Importance

The 2013/2014 American Society of Clinical Oncology and College of American Pathologists (ASCO-CAP) guidelines for HER2 testing by fluorescence in situ hybridization (FISH) designated an "equivocal" category (average HER2 copies per tumor cell ≥4-6 with HER2/CEP17 ratio <2.0) to be resolved as negative or positive by assessments with alternative control probes. Approximately 4% to 12% of all invasive breast cancers are characterized as HER2-equivocal based on FISH.

Objective

To evaluate the following hypotheses: (1) genetic loci used as alternative controls are heterozygously deleted in a substantial proportion of breast cancers; (2) use of these loci for assessment of HER2 by FISH leads to false-positive assessments; and (3) these HER2 false-positive breast cancer patients have outcomes that do not differ from clinical outcomes for patients with HER2-negative breast cancer.

Design, Setting, and Participants

We retrospectively assessed the use of chromosome 17 p-arm and q-arm alternative control genomic sites (TP53, D17S122, SMS, RARA, TOP2A), as recommended by the 2013/2014 ASCO-CAP guidelines for HER2 testing, in patients whose data were available through Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) and whose tissues were available through the Breast Cancer International Research Group clinical trials. We used data from an international cohort database of invasive breast cancers (1980 participants) and international clinical trial of adjuvant chemotherapy in invasive, node-positive breast cancer patients.

Main Outcomes and Measures

The primary objectives were to (1) assess frequency of heterozygous deletions in chromosome 17 genomic sites used as FISH internal controls for evaluation of HER2 status among HER2-equivocal cancers; (2) characterize impact of using deleted sites for determination of HER2-to-internal-control-gene ratios; (3) assess HER2 protein expression in each subgroup; and (4) compare clinical outcomes for each subgroup.

Results

Of the 1980 patients in METABRIC,1915 patients were fully evaluated. In addition, 100 HER2-equivocal breast cancers by FISH and 100 comparator FISH-negative breast cancers from the BCIRG-005 trial were analyzed. Heterozygous deletions, particularly in specific p-arm sites, were common in both HER2-amplified and HER2-not-amplified breast cancers. Use of alternative control probes from these regions to assess HER2 by FISH in HER2-equivocal as well as HER2-not-amplified breast cancers resulted in high rates of false-positive ratios (HER2-to-alternative control ratio ≥2.0) owing to heterozygous deletions of control p-arm genomic sites used in ratio denominators. Misclassification of HER2 status was observed not only in breast cancers with ASCO-CAP equivocal status but also in breast cancers with an average of fewer than 4.0 HER2 copies per tumor cell when using alternative control probes.

Conclusions and Relevance

The indiscriminate use of alternative control probes to calculate HER2 FISH ratios in HER2-equivocal breast cancers may lead to false-positive interpretations of HER2 status resulting from unrecognized heterozygous deletions in 1 or more of these alternative control genomic sites and incorrect HER2 ratio determinations.

NSABP B-47/NRG Oncology Phase III Randomized Trial Comparing Adjuvant Chemotherapy With or Without Trastuzumab in High-Risk Invasive Breast Cancer Negative for HER2 by FISH and With IHC 1+ or 2

PURPOSE

Adjuvant trastuzumab reduces invasive breast cancer (IBC) recurrence and risk for death in patients with HER2-amplified or overexpressing IBC. A subset of patients in the landmark trastuzumab adjuvant trials who originally tested HER2-positive but were HER2-negative by central HER2 testing appeared to possibly benefit from trastuzumab. The objective for the NSABP B-47 trial was to determine whether the addition of trastuzumab to adjuvant chemotherapy (CRx) would improve invasive disease-free survival (IDFS) in patients with HER2-negative breast cancer.

PATIENTS AND METHODS

A total of 3,270 women with high-risk primary IBC were randomly assigned to CRx with or without 1 year of trastuzumab. Eligibility criteria included immunohistochemistry (IHC) score 1+ or 2+ with fluorescence in situ hybridization ratio (FISH) < 2.0 or, if ratio was not performed, HER2 gene copy number < 4.0. CRx was either docetaxel plus cyclophosphamide or doxorubicin and cyclophosphamide followed by weekly paclitaxel for 12 weeks.

RESULTS

At a median follow-up of 46 months, the addition of trastuzumab to CRx did not improve IDFS (5-year IDFS: 89.8% with CRx plus trastuzumab [CRxT] v 89.2% with CRx alone; hazard ratio [HR], 0.98; 95% CI, 0.76 to 1.25; P = .85). These findings did not differ by level of HER2 IHC expression, lymph node involvement, or hormone-receptor status. For distant recurrence-free interval, 5-year estimates were 92.7% with CRxT compared with 93.6% for CRx alone (HR, 1.10; 95% CI, 0.81 to 1.50; P = .55) and for overall survival (OS) were 94.8% with CRxT and 96.3% in CRx alone (HR, 1.33; 95% CI, 0.90 to 1.95; P = .15). There were no unexpected toxicities from the addition of trastuzumab to CRx.

CONCLUSION

The addition of trastuzumab to CRx did not improve IDFS, distant recurrence-free interval, or OS in women with non-HER2-overexpressing IBC. Trastuzumab does not benefit women without IHC 3+ or FISH ratio-amplified breast cancer.

Single-molecule detection of biomarker and localized cellular photothermal therapy using an optical microfiber with nanointerface

For early-stage diagnostics, there is a strong demand for sensors that can rapidly detect biomarkers at ultralow concentration or even at the single-molecule level. Compared with other types of sensors, optical microfibers are more convenient for use as point-of-care devices in early-stage diagnostics. However, the relatively low sensitivity strongly hinders their use. To this end, an optical microfiber is functionalized with a plasmonic nanointerface consisting of black phosphorus-supported Au nanohybrids. The microfiber is able to detect epidermal growth factor receptor (ErbB2) at concentrations ranging from 10 zM to 100 nM, with a detection limit of 6.72 zM, enabling detection at the single-molecule level. The nanointerface-sensitized microfiber is capable of differentiating cancer cells from normal cells and treating cancer cells through cellular photothermal therapy. This work opens up a possible approach for the integration of cellular diagnosis and treatment.

Genomic Amplifications and Distal 6q Loss: Novel Markers for Poor Survival in High-risk Neuroblastoma Patients

Background

Neuroblastoma is characterized by substantial clinical heterogeneity. Despite intensive treatment, the survival rates of high-risk neuroblastoma patients are still disappointingly low. Somatic chromosomal copy number aberrations have been shown to be associated with patient outcome, particularly in low- and intermediate-risk neuroblastoma patients. To improve outcome prediction in high-risk neuroblastoma, we aimed to design a prognostic classification method based on copy number aberrations.

Methods

In an international collaboration, normalized high-resolution DNA copy number data (arrayCGH and SNP arrays) from 556 high-risk neuroblastomas obtained at diagnosis were collected from nine collaborative groups and segmented using the same method. We applied logistic and Cox proportional hazard regression to identify genomic aberrations associated with poor outcome.

Results

In this study, we identified two types of copy number aberrations that are associated with extremely poor outcome. Distal 6q losses were detected in 5.9% of patients and were associated with a 10-year survival probability of only 3.4% (95% confidence interval [CI] = 0.5% to 23.3%, two-sided P = .002). Amplifications of regions not encompassing the MYCN locus were detected in 18.1% of patients and were associated with a 10-year survival probability of only 5.8% (95% CI = 1.5% to 22.2%, two-sided P < .001).

Conclusions

Using a unique large copy number data set of high-risk neuroblastoma cases, we identified a small subset of high-risk neuroblastoma patients with extremely low survival probability that might be eligible for inclusion in clinical trials of new therapeutics. The amplicons may also nominate alternative treatments that target the amplified genes.

Immunohistochemistry for diagnosis and prognosis of breast cancer: a review

Breast cancer is the most prevalent malignant tumor and main oncologic cause of mortality in women. Although most diagnosis of breast pathology is accomplished using hematoxylin and eosin stained sections, some cases require immunohistochemistry for proper evaluation. We investigated the latter cases including distinctions between ductal and lobular carcinoma, in situ and invasive carcinoma, typical ductal hyperplasia and atypical ductal hyperplasia/ductal carcinoma in situ, papillary and spindle cell lesion assessment, metastasis evaluation, and assessment of prognostic and therapy markers. E-cadherin is used to differentiate ductal and lobular carcinoma; 34βE12, CK8, p120 catenin and β-catenin also produce consistent results. Myoepithelial cell (MEC) stains are used to evaluate in situ and invasive carcinoma; calponin, smooth muscle myosin heavy chain and p63 are sensitive/specific markers. 34βE12 and CK5/6 are positive in ductal hyperplasia, which enables its differentiation from atypical ductal hyperplasia and ductal carcinoma in situ. CK 5/6, ER and MEC markers are consistent options for evaluating papillary lesions. Spindle cell lesions can be assessed using β-catenin, SMA, CD34, p63, CKs and hormone receptors. It is important to differentiate primary carcinomas from metastases; the most commonly used markers to identify breast origin include mammaglobin, GCDFP-15, GATA3 and ER, although none of these is completely sensitive or specific. Immunohistochemistry can be used to evaluate central prognostic and predictive factors including molecular subtypes, HER2, hormone receptors, proliferation markers (Ki-67) and lymph-vascular invasion markers including ERG, CD31, CD34, factor VIII and podoplanin. Owing to the complexity of mammary lesions, diagnosis also depends on each particular situation, evaluation of cytological characteristics revealed by immunochemistry and correlation with histological findings.

The Impact of Partial Weak Staining in Normal Breast Epithelium on the Reliability of Immunohistochemistry Results in HercepTest-positive Breast Cancer

INTRODUCTION

Although normal epithelial cells do not show human epidermal growth factor receptor-2 (HER2) gene amplification and should lack membrane staining by HER2 immunohistochemistry (IHC), HER2 staining in benign breast epithelium is occasionally encountered. The significance of this occurrence has not yet been adequately studied, and its associated American Society of Clinical Oncology/College of American Pathologists recommendations are vague. Our objective is to assess the correlation between HER2 IHC 3+ breast cancer cases with normal epithelium staining (NES) and their corresponding fluorescence in situ hybridization (FISH) results, and to suggest recommendations for interpretation.

MATERIALS AND METHODS

A total of 154 breast cancer cases with HER2 IHC 3+ were reviewed. NES, along with other clinicopathologic characteristics, were recorded. NES was scored as present or absent. All study cases were sent for FISH testing. All cases, and particularly those that showed false positivity for IHC (positive IHC, negative FISH) were examined for NES.

RESULTS

Of the 154 cases, 146 cases were FISH-positive (94.8%) and 2 failed FISH testing (1.3%). Conversely, 22% (34/154) of the cases showed NES for HER2. Of these 34 cases, 23 (67%) were FISH-amplified, 9 (26%) were FISH not amplified, and 2 failed FISH testing. Notably, all of the false-positive (FISH-negative) breast cancer cases showed some degree of positivity in normal breast epithelium.

CONCLUSIONS

Our findings, though descriptive, show a very strong association between NES and false-positive HER2 IHC. This confirms the need to carefully evaluate IHC-positive breast cancers for NES, and to have a low threshold for confirmatory testing by FISH.

Effect of a Collaboration Between a Health Plan, Oncology Practice, and Comprehensive Genomic Profiling Company from the Payer Perspective

BACKGROUND

Comprehensive genomic profiling (CGP) is a next-generation sequencing-based methodology that detects 4 classes of genomic alterations, as well as gene signature biomarkers such as microsatellite instability and tumor mutational burden. In the context of precision oncology, CGP can help to direct treatment to genomically matched therapies.

OBJECTIVE

To describe the results of a 3-year observational analysis of patients undergoing testing with CGP assays (either FoundationOne or FoundationOne Heme) at a community oncology practice after a regional health plan implemented a medical policy that enabled coverage of CGP.

METHODS

A retrospective analysis of medical records was completed at the oncology practice from November 2013 to January 2017; this date range was chosen to coincide with the regional health plan's medical policy implementation of CGP. The medical policy provided coverage of CGP for patients with advanced solid and hematologic cancers. A medical record review assessed all previous and current molecular test results, matched therapy or clinical trial enrollment, and clinical outcomes (clinical benefit or disease progression). The potential cost diversion, from payer to study sponsor, for patients who enrolled in clinical trials was explored.

RESULTS

There were 96 patients in the community oncology practice who received CGP over the 3-year period, 86 of whom had clinically relevant genomic alterations. Of the 86, 15 patients were treated with genomically matched therapy, and 6 patients enrolled in clinical trials based on CGP results. In a subset of 32 patients who previously underwent conventional testing, most (84%) had clinically relevant genomic alterations detected by CGP that conventional testing did not identify, and a portion of these patients subsequently received treatment based on the CGP results. In the separate cost diversion analysis of 20 patients who enrolled in phase 1 clinical trials, an estimated $25,000 per-patient cost-benefit may have been accrued to the payer.

CONCLUSIONS

This observational analysis characterized the use of CGP in a large community oncology practice among a group of patients insured by a regional health plan. Clinical trial enrollment was facilitated by CGP use in the community setting and may have contributed to cost diversion from the payer to study sponsors.

DISCLOSURES

No separate study-related funding was provided by or to Priority Health, Foundation Medicine, and Cancer and Hematology Centers of West Michigan. Data analysis by Reitsma was conducted as part of an internship funded by Priority Health. Reitsma and Fox are employed by Priority Health. Anhorn, Vanden Borre, Cavanaugh, Chudnovsky, and Erlich are employed by Foundation Medicine.

Molecular alterations and poziotinib efficacy, a pan-HER inhibitor, in human epidermal growth factor receptor 2 (HER2)-positive breast cancers: Combined exploratory biomarker analysis from a phase II clinical trial of poziotinib for refractory HER2-positive breast cancer patients

We aimed to investigate the impact of genetic alterations on the efficacy of poziotinib in a phase II clinical trial of patients with heavily treated HER2-positive metastatic breast cancer (BC). We performed targeted ultra-deep sequencing with a customized cancer gene panel and RNA expression assay using BC specimens. Of 106 patients, biomarker data were available for 85. Copy number (CN) amplifications of HER2 were observed in 72 patients (85%), and CN >8 in 50 (59%). Single nucleotide variants (SNVs) of HER2 were found in 16 patients (19%). Genetic alterations of PIK3CA pathway were found in 40 patients (47%). Median progression free survival (PFS) of the biomarker analysis group was 3.61 months. In terms of PFS, HER2 with CN >8 prolonged (hazard ratio (HR) 0.61, 95% CI: 0.38, 0.97, p = 0.037) and alteration of PIK3CA pathway shortened the duration of survival (HR 2.25, 95% CI: 1.39, 3.63, p = 0.001). SNVs of HER2 increased survival duration, but the effect was not significant (HR: 0.58, 95% CI: 0.31, 1.08, p = 0.085). In addition, SNVs in the ERBB3 cytoplasmic domain decreased poziotinib response (HR: 4.58, 95% CI: 2.02, 10.37, p < 0.001). In multigene analysis, BC with HER2 CN >8 and intact PIK3CA pathway had significantly longer PFS compared to others (HR: 0.37, 95% CI: 0.21, 0.66, p = 0.001), while SNVs in the ERBB3 cytoplasmic domain predicted poor prognosis (HR: 4.28, 95% CI: 1.71, 10.71, p < 0.001). In conclusion, HER2 CN amplification, PIK3CA pathway alteration, and ERBB3 cytoplasmic mutation showed predictive roles on clinical outcomes of HER2-positive MBC treated with poziotinib.

Correlation Between HER-2 Gene Amplification or Protein Expression and Clinical Pathological Features of Breast Cancer

OBJECTIVE

The incidence of breast cancer in females is gradually increasing. Expression of HER-2 gene and protein is critical for predicting the prognosis of breast cancer. This study examined amplification of HER-2 gene and protein expression in breast cancer patients to analyze their correlation with clinical and pathological features.

MATERIALS AND METHODS

Specimens of breast gland tissues were collected from breast cancer patients for measuring HER-2 protein expression by immunohistochemistry (IHC) method. Fluorescent in situ hybridization (FISH) measured HER-2 gene amplification. The consistency of HER-2 protein and gene expression was analyzed in addition to their correlation with clinical and pathological features of patients.

RESULTS

Thirty-six percent patients showed negative expression of HER-2 protein, and 9%, 32%, and 23% of them had positive expression to different levels (+, ++, and +++). Forty percent patients were positive for HER-2 gene amplification, including 3, 21, and 14 cases of (+), (++), and (+++) patients. Expression of HER-2 protein was highly correlated with HER-2 gene amplification (r = 1.262; p < 0.05). Both parameters were correlated with tumor size, differentiation grade, lymph node metastasis, and TNM stage (p < 0.05).

CONCLUSIONS

Combined assay of IHC and FISH for detecting HER-2 protein or gene amplification in breast cancer tissues showed their correlation with tumor size, differentiation grade, lymph node metastasis, and TNM stage.

Differential regulation of human monocytes and NK cells by antibody-opsonized tumors

The monocyte network is important for therapeutic efficacy of antibody therapies against cancer. One mechanism which monocytes/macrophages use to kill cancer cells is phagocytosis. Using trastuzumab and human breast cancer cell lines as a model, we used flow cytometry to evaluate the importance of avidity, antigen density, Fcγ receptor (FcγR) expression, and FcγR polymorphisms in human monocyte phagocytosis. By increasing avidity for the tumor through the addition of pertuzumab to trastuzumab, there was a two-to-threefold increase in phagocytosis potency against the HCC1419 cell line compared to antibodies alone, while NK cell-mediated antibody-dependent cellular cytotoxicity (ADCC) failed to increase tumor cell death. Consistent with increasing the avidity through multiple antibodies, antigen density significantly enhanced phagocytosis with breast cancer cell lines that were HER2 gene-amplified compared to non-amplified tumor cells. Confirmation that high antigen density enhanced phagocytosis was obtained when HER2 was overexpressed in HER2 non-amplified cell lines. In contrast, NK cell ADCC failed to distinguish differences in tumor cell death when comparing gene-amplified and non-amplified breast cancer cell lines. The level of phagocytosis was influenced by FcγRIIa and FcγRIIIa expression. Most monocytes are FcγRIIIa-, and the induction of the receptor significantly enhances antibody-dependent phagocytosis. Although both receptors are involved, when blocked FcγRIIIa had a greater influence on phagocytosis. Furthermore, the polymorphism FcγRIIIa 158V significantly enhanced phagocytosis; whereas FcγRIIa 131H polymorphism appeared to improve phagocytosis but was not statistically significant. Targeting of monocytes for enhanced phagocytosis may improve the effectiveness of therapeutic antibodies to improve clinical outcomes.

Preclinical models for precision oncology

Precision medicine approaches have revolutionized oncology. Personalized treatments require not only identification of the driving molecular alterations, but also development of targeted therapies and diagnostic tests to identify the appropriate patient populations for clinical trials and subsequent therapeutic implementation. Preclinical in vitro and in vivo models are widely used to predict efficacy of newly developed treatments. Here we discuss whether, and to what extent, preclinical models including cell lines, organoids and tumorgrafts recapitulate key features of human tumors. The potential of preclinical models to anticipate treatment efficacy and clinical benefit is also presented, using examples in different tumor types.

Clinical development of HER3-targeting monoclonal antibodies: Perils and progress

The human epidermal growth factor receptor (HER) family consists of four transmembrane receptor tyrosine kinases: epidermal growth factor receptor (EGFR), HER2, HER3, and HER4. They are part of a complex signalling network and stimulate intracellular pathways regulating cell growth and differentiation. So far, monoclonal antibodies (mAbs) and small molecule tyrosine kinase inhibitors targeting EGFR and HER2 have been developed and approved. Recently, focus has turned to HER3 as it may play an important role in resistance to EGFR- and HER2-targeting therapies. HER3-targeting agents have been undergoing clinical evaluation for the last 10 years and currently thirteen mAbs are in phase 1 or 2 clinical studies. Single agent activity has proven to be limited, however, the tolerability was favourable. Thus, combinations of HER3-binding mAbs with other HER-targeting therapies or chemotherapies have been pursued in various solid tumor entities. Data indicate that the HER3-binding ligand heregulin may serve as a response prediction marker for HER3-targeting therapy. Within this review the current status of clinical development of HER3-targeting compounds is described.

Standardization and optimization of fluorescence in situ hybridization (FISH) for HER-2 assessment in breast cancer: A single center experience

Accurate assessment of human epidermal growth factor receptor 2 (HER-2) is crucial in selecting patients for targeted therapy. Commonly used methods for HER-2 testing are immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Here we presented the implementation, optimization and standardization of two FISH protocols using breast cancer samples and assessed the impact of pre-analytical and analytical factors on HER-2 testing. Formalin fixed paraffin embedded (FFPE) tissue samples from 70 breast cancer patients were tested for HER-2 using PathVysion™ HER-2 DNA Probe Kit and two different paraffin pretreatment kits, Vysis/Abbott Paraffin Pretreatment Reagent Kit (40 samples) and DAKO Histology FISH Accessory Kit (30 samples). The concordance between FISH and IHC results was determined. Pre-analytical and analytical factors (i.e., fixation, baking, digestion, and post-hybridization washing) affected the efficiency and quality of hybridization. The overall hybridization success in our study was 98.6% (69/70); the failure rate was 1.4%. The DAKO pretreatment kit was more time-efficient and resulted in more uniform signals that were easier to interpret, compared to the Vysis/Abbott kit. The overall concordance between IHC and FISH was 84.06%, kappa coefficient 0.5976 (p < 0.0001). The greatest discordance (82%) between IHC and FISH was observed in IHC 2+ group. A standardized FISH protocol for HER-2 assessment, with high hybridization efficiency, is necessary due to variability in tissue processing and individual tissue characteristics. Differences in the pre-analytical and analytical steps can affect the hybridization quality and efficiency. The use of DAKO pretreatment kit is time-saving and cost-effective.

Highly Sensitive Detection of Protein Biomarkers with Organic Electrochemical Transistors

The analysis of protein biomarkers is of great importance in the diagnosis of diseases. Although many convenient and low-cost electrochemical approaches have been extensively investigated, they are not sensitive enough in the detection of protein biomarkers with low concentrations in physiological environments. Here, this study reports a novel organic-electrochemical-transistor-based biosensor that can successfully detect cancer protein biomarkers with ultrahigh sensitivity. The devices are operated by detecting electrochemical activity on gate electrodes, which is dependent on the concentrations of proteins labeled with catalytic nanoprobes. The protein sensors can specifically detect a cancer biomarker, human epidermal growth factor receptor 2, down to the concentration of 10^-14 g mL^-1 , which is several orders of magnitude lower than the detection limits of previously reported electrochemical approaches. Moreover, the devices can successfully differentiate breast cancer cells from normal cells at various concentrations. The ultrahigh sensitivity of the protein sensors is attributed to the inherent amplification function of the organic electrochemical transistors. This work paves a way for developing highly sensitive and low-cost biosensors for the detection of various protein biomarkers in clinical analysis in the future.

Precision oncology using a clinician-directed, tailored approach to molecular profiling

AIM

Precision oncology involves molecularly matching patients to targeted agents usually in early drug development (EDD) programs. Molecular profiling (MP) identifies actionable targets. Comprehensive commercial MP platforms are costly and in resource limited environments, a more practical approach to MP is necessary to support EDD and precision oncology. We adopted a clinician-directed, tailored approach to MP to enrol patients onto molecularly targeted trials. We report the feasibility of this approach.

METHODS

All patients referred to the Royal Melbourne Hospital (RMH) EDD between September 2013 and September 2015 were identified in a prospective database. Key captured data included clinicopathological data, MP platform ordered (if any), molecular targets identified and subsequent enrolment onto clinical trials. EDD-clinician decisions to order MP and the platform utilized was guided by patient consultation, tumor type, trial availability and requirement for molecular information.

RESULTS

We identified 377 patients referred to RMH EDD. A total of 216 (57%) had MP ordered. The remainder had known actionable targets (19%), or were inappropriate for clinical trials (24%). In those undergoing MP, 187 genetic aberrations were found in 113 patients with 98 considered actionable targets in 86 patients. Ninety-eight (25%) patients were enrolled onto a clinical trial, including 40 (11%) receiving molecularly matched treatments. Median progression-free survival was improved in patients enrolled onto molecularly matched trials compared to those on unmatched trials (3.6 months vs 1.9 months, HR 0.58 [0.38-0.89], P  =  0.013).

CONCLUSION

A clinician-directed, tailored approach to the use of MP is feasible, resulting in 11% of patients enrolled onto molecularly matched trials.

HER2 Gene Amplification Testing by Fluorescent In Situ Hybridization (FISH): Comparison of the ASCO-College of American Pathologists Guidelines With FISH Scores Used for Enrollment in Breast Cancer International Research Group Clinical Trials

Purpose

ASCO and the College of American Pathologists (ASCO-CAP) recently recommended further changes to the evaluation of human epidermal growth factor receptor 2 gene (HER2) amplification by fluorescent in situ hybridization (FISH). We retrospectively assessed the impact of these new guidelines by using annotated Breast Cancer International Research Group (BCIRG) -005, BCIRG-006, and BCIRG-007 clinical trials data for which we have detailed outcomes.

Patients and Methods

The HER2 FISH status of BCIRG-005/006/007 patients with breast cancers was re-evaluated according to current ASCO-CAP guidelines, which designates five different groups according to HER2 FISH ratio and average HER2 gene copy number per tumor cell: group 1 (in situ hybridization [ISH]–positive): HER2-to-chromosome 17 centromere ratio ≥ 2.0, average HER2 copies ≥ 4.0; group 2 (ISH-positive): ratio ≥ 2.0, copies < 4.0; group 3 (ISH-positive): ratio < 2.0, copies ≥ 6.0; group 4 (ISH-equivocal): ratio < 2.0, copies ≥ 4.0 and < 6.0; and group 5 (ISH-negative): ratio < 2.0, copies < 4.0. We assessed correlations with HER2 protein, clinical outcomes by disease-free survival (DFS) and overall survival (OS) and benefit from trastuzumab therapy (hazard ratio [HR]).

Results

Among 10,468 patients with breast cancers who were successfully screened for trial entry, 40.8% were in ASCO-CAP ISH group 1, 0.7% in group 2; 0.5% in group 3, 4.1% in group 4, and 53.9% in group 5. Distributions were similar in screened compared with accrued subpopulations. Among accrued patients, FISH group 1 breast cancers were strongly correlated with immunohistochemistry 3+ status (P < .0001), whereas groups 2, 3, 4, and 5 were not; however, groups 2, 4 and, 5 were strongly correlated with immunohistochemistry 0/1+ status (all P < .0001), whereas group 3 was not. Among patients accrued to BCIRG-005, group 4 was not associated with significantly worse DFS or OS compared with group 5. Among patients accrued to BCIRG-006, only group 1 showed a significant benefit from trastuzumab therapy (DFS HR, 0.71; 95% CI, 0.60 to 0.83; P < .0001; OS HR, 0.69; 95% CI, 0.55 to 0.85; P = .0006), whereas group 2 did not.

Conclusion

Our findings support the original categorizations of HER2 by FISH status in BCIRG/Translational Research in Oncology trials.

Exploitation of Gene Expression and Cancer Biomarkers in Paving the Path to Era of Personalized Medicine

Cancer therapy agents have been used extensively as cytotoxic drugs against tissue or organ of a specific type of cancer. With the better understanding of molecular mechanisms underlying carcinogenesis and cellular events during cancer progression and metastasis, it is now possible to use targeted therapy for these molecular events. Targeted therapy is able to identify cancer patients with dissimilar genetic defects at cellular level for the same cancer type and consequently requires individualized approach for treatment. Cancer therapy begins to shift steadily from the traditional approach of “one regimen for all patients” to a more individualized approach, through which each patient will be treated specifically according to their specific genetic defects. Personalized medicine accordingly requires identification of indicators or markers that guide in the decision making of such therapy to the chosen patients for more effective therapy. Cancer biomarkers are frequently used in clinical practice for diagnosis and prognosis, as well as identification of responsive patients and prediction of treatment response of cancer patient. The rapid breakthrough and development of microarray and sequencing technologies is probably the main tool for paving the way toward “individualized biomarker-driven cancer therapy” or “personalized medicine”. In this review, we aim to provide an updated knowledge and overview of the current landscape of cancer biomarkers and their role in personalized medicine, emphasizing the impact of genomics on the implementation of new potential targeted therapies and development of novel cancer biomarkers in improving the outcome of cancer therapy.

Image Analysis of the Tumor Microenvironment

In the field of pathology it is clear that molecular genomics and digital imaging represent two promising future directions, and both are as relevant to the tumor microenvironment as they are to the tumor itself (Beck AH et al. Sci Transl Med 3(108):108ra113-08ra113, 2011). Digital imaging, or whole slide imaging (WSI), of glass histology slides facilitates a number of value-added competencies which were not previously possible with the traditional analog review of these slides under a microscope by a pathologist. As an important tool for investigational research, digital pathology can leverage the quantification and reproducibility offered by image analysis to add value to the pathology field. This chapter will focus on the application of image analysis to investigate the tumor microenvironment and how quantitative investigation can provide deeper insight into our understanding of the tumor to tumor microenvironment relationship.

Over-using chemotherapy in the adjuvant setting

Avoidance of unnecessary or ineffective treatment should be one of the main goals in adjuvant breast oncology today. Unfortunately, both patients and doctors hunt for tiny statistical differences in survival curves. This search could not only lead to an oncological approach of unlimited addition that we will not be able to afford, but would also end inevitably in indeterminate overtreatment with substantial risks of unexpected toxic effects eating away whatever progress we might make. "Do not harm" remains the main principle in medicine. To be able to follow this rule, we need to better understand the biology of breast cancer. The mistake of "one treatment fits all" can only be changed when we critically review trial designs of adjuvant breast oncology. The risk of overtreatment is there and selection of precisely defined cohorts for phase 3 trials is necessary, despite pressure of scientific ambition, pragmatism, and demands of industry. The "add on" clinical trial design model accepts the inability to confirm that standard therapy is still necessary if a positive result from the addition of the new therapy is obtained. The same model can be applied to "extended" adjuvant treatments in breast cancer subtypes. Addition of "miraculin" to the standard of care should generate a new standard. Such trials that show a modest benefit on average at a population level take us a step away from refining care for the individual, and might support the use of multiple and costly interventions with potential short and long term side effects. It is essential to escalate treatment when necessary and to de-escalate when un-necessary.

Glioma FMISO PET/MR Imaging Concurrent with Antiangiogenic Therapy: Molecular Imaging as a Clinical Tool in the Burgeoning Era of Personalized Medicine

The purpose of this article is to provide a focused overview of the current use of positron emission tomography (PET) molecular imaging in the burgeoning era of personalized medicine in the treatment of patients with glioma. Specifically, we demonstrate the utility of PET imaging as a tool for personalized diagnosis and therapy by highlighting a case series of four patients with recurrent high grade glioma who underwent 18F-fluoromisonidazole (FMISO) PET/MR (magnetic resonance) imaging through the course of antiangiogenic therapy. Three distinct features were observed from this small cohort of patients. First, the presence of pseudoprogression was retrospectively associated with the absence of hypoxia. Second, a subgroup of patients with recurrent high grade glioma undergoing bevacizumab therapy demonstrated disease progression characterized by an enlarging nonenhancing mass with newly developed reduced diffusion, lack of hypoxia, and preserved cerebral blood volume. Finally, a reduction in hypoxic volume was observed concurrent with therapy in all patients with recurrent tumor, and markedly so in two patients that developed a nonenhancing reduced diffusion mass. This case series demonstrates how medical imaging has the potential to influence personalized medicine in several key aspects, especially involving molecular PET imaging for personalized diagnosis, patient specific disease prognosis, and therapeutic monitoring.

Clinicopathological and Survival Analysis of Japanese Patients with Resected Non-Small-Cell Lung Cancer Harboring NKX2-1, SETDB1, MET, HER2, SOX2, FGFR1, or PIK3CA Gene Amplification

INTRODUCTION

Gene amplification is an important genetic change in cancer cells. We investigated the prevalence, clinicopathological characteristics, and prognostic value of NKX2-1 (also known as TTF-1), SETDB1, MET, HER2, SOX2, FGFR1, and PIK3CA amplification in Japanese patients with non-small-cell lung cancer (NSCLC).

METHODS

The copy numbers of the seven above-mentioned genes were assessed using fluorescence in situ hybridization in a tissue microarray containing 282 surgically resected NSCLC specimens (164 adenocarcinoma [AC], 99 squamous cell carcinoma [SCC], and 19 others). Clinicopathological information were obtained from the medical records.

RESULTS

NKX2-1, SETDB1, MET, HER2, SOX2, FGFR1, and PIK3CA gene amplification were observed in 30 of 277 (10.8%), 16 of 280 (5.7%), 38 of 278 (13.7%), 8 of 270 (3.0%), 34 of 278 (12.2%), 18 of 282 (6.4%), and 53 of 278 (19.1%) cases, respectively. Coamplification was detected in 16 of 156 (10.3%) AC patients and 35 of 93 (37.6%) SCC patients (p < 0.0001). NKX2-1 amplification was significantly related to an AC histology (p = 0.004), whereas SOX2, FGFR1, and PIK3CA amplifications were related to a SCC histology (p < 0.0001). Within the ACs, NKX2-1 and SETDB1 amplifications were markers of a shorter survival period. A multivariate Cox proportional hazards model revealed that NKX2-1 amplification was an independent predictor of poor survival (hazard ratio, 2.938; 95% confidence interval, 1.434-6.022; p = 0.003). Coamplification had impact on patient outcome in AC but not in entire NSCLC and SCC.

CONCLUSIONS

The amplification status differed among the histological types of NSCLC. NKX2-1 amplification was an independent and the most practically important predictor of a poor prognosis among Japanese patients with AC.

Intratumoral Heterogeneity of HER-2/neu in Invasive Mammary Carcinomas Using Fluorescence In-Situ Hybridization and Tissue Microarray

Fluorescence in-situ hybridization is increasingly being used to determine HER-2/neu status in patients with breast carcinoma. The possibility that intratumoral heterogeneity of HER-2/neu gene amplification may potentially contribute to inaccurate assessment of HER-2/neu status was investigated in routine cases of invasive mammary carcinomas. From 169 representative formalin-fixed, paraffin-embedded blocks of invasive duct mammary carcinomas with grade 3 architecture, 48 cases were analyzed by fluorescence in-situ hybridization and 59 analyses were performed. Intratumoral heterogeneity for HER-2/neu gene amplification was demonstrated in only 5 (16%) of 31 cases where morphologically similar areas of a single tumor were analyzed. We conclude from this study that intratumoral heterogeneity of HER-2/neu gene amplification is a demonstrable but relatively uncommon occurrence. For invasive mammary carcinomas, the accurate assessment of HER-2/neu status by fluorescence in-situ hybridization analysis is not significantly confounded by intratumoral heterogeneity of HER-2/neu gene amplification in individual tumors.

First-line therapy in HER2 positive metastatic breast cancer: is the mosaic fully completed or are we missing additional pieces?

The discovery of human epidermal growth factor receptor 2 (HER2) and its role in the biology of breast cancer and the subsequent development of HER2-targeted therapies, have dramatically improved clinical outcomes for women with early-stage and advanced HER2-positive breast cancer (BC).

HER-2 targeted therapies represent a major step forward in achieving the goal of delivering individualized targeted therapy for BC, and trastuzumab was the first anti-HER-2 strategy to be approved for treatment of HER-2 positive BC.

This review discusses the treatment of metastatic HER2-positive BC and describes efficacy and safety of novel anti-HER2 target therapies in first-line metastatic settings and the future challenges include refining such treatments, reducing toxicity and simultaneously developing innovative therapies. Furthermore, combinations of trastuzumab and drugs targeting the downstream pathway are described.

In the next future will be possible to use an ample armamentarium of combination therapies directed against HER2 and key signaling components integrated in the HER network. This approach will allow clinicians to tailor the management of the individual patient on the basis of tumor- specific biomarker profiles.

There is an urgent need for prospective biomarker-driven trials to identify patients for whom targeting is cost-effective.