HER2 in gastric cancer: a digital image analysis in pre-neoplastic, primary and metastatic lesions

Advances in Human Epidermal Growth Factor Receptor 2-Targeted Therapy in Upper Gastrointestinal Cancers

The Trastuzumab for Gastric Cancer (ToGA) trial marked a pivotal moment in the adoption of trastuzumab for treating advanced human epidermal growth factor receptor 2 (HER2)-positive esophagogastric (EG) cancer. The KEYNOTE-811 trial brought to light the synergistic effect of immune modulation and HER2 targeting. Additionally, the emergence of trastuzumab deruxtecan (T-DXd) highlighted the potential of new pharmaceutical technologies to extend response, particularly for patients who have advanced beyond initial HER2-targeted therapies. This review aims to navigate through both the successes and challenges encountered historically, as well as promising current trials on innovative and transformative therapeutic strategies, including promising first-in-class and novel first-in-human agents.

Molecular classification and intratumoral heterogeneity of gastric adenocarcinoma

Gastric cancers frequently harbor striking histological complexity and diversity between lesions as well as within single lesions, known as inter- and intratumoral heterogeneity, respectively. The latest World Health Organization Classification of Tumors designated more than 30 histological subtypes for gastric epithelial tumors, assigning 12 subtypes for gastric adenocarcinoma (GAD). Meanwhile, recent advances in genome-wide analyses have provided molecular aspects to the histological classification of GAD, and consequently revealed different molecular traits underlying these histological subtypes. Moreover, accumulating knowledge of comprehensive molecular profiles has led to establishing molecular classifications of GAD, which are often associated with clinical biomarkers for therapeutics and prognosis. However, most of our knowledge of GAD molecular profiles is based on inter-tumoral heterogeneity, and the molecular profiles underlying intratumoral heterogeneity are yet to be determined. In this review, recently established molecular classifications of GAD are introduced in the aspect of pathological diagnosis and are discussed in the context of intratumoral heterogeneity.

Detection of chromosomal instability using ultrasensitive chromosomal aneuploidy detection in the diagnosis of precancerous lesions of gastric cancer

Background

The diagnosis of Precancerous Lesions of Gastric Cancer (PLGC) is challenging in clinical practice. We conducted a clinical study by analyzing the information of relevant chromosome copy number variations (CNV) in the TCGA database followed by the UCAD technique to evaluate the value of Chromosomal Instability (CIN) assay in the diagnosis of PLGC.

Methods

Based on the screening of gastric cancer related data in TCGA database, CNV analysis was performed to explore the information of chromosome CNV related to gastric cancer. Based on the gastroscopic pathology results, 12 specimens of patients with severe atrophy were screened to analyze the paraffin specimens of gastric mucosa by UCAD technology, and to explore the influence of related factors on them.

Results

The results of CNV in TCGA database suggested that chromosome 7, 8, and 17 amplification was obvious in patients with gastric cancer. UCAD results confirmed that in 12 patients with pathologic diagnosis of severe atrophy, five of them had positive results of CIN, with a positive detection rate of 41.7%, which was mainly manifested in chromosome seven and chromosome eight segments amplification. We also found that intestinalization and HP infection were less associated with CIN. And the sensitivity of CIN measurement results was significantly better than that of tumor indicators.

Conclusion

The findings suggest that the diagnosis of PLGC can be aided by UCAD detection of CIN, of which Chr7 and 8 may be closely related to PLGC.

Advancing the PD-L1 CPS test in metastatic TNBC: Insights from pathologists and findings from a nationwide survey

Pembrolizumab has received approval as a first-line treatment for unresectable/metastatic triple-negative breast cancer (mTNBC) with a PD-L1 combined positive score (CPS) of ≥ 10. However, assessing CPS in mTNBC poses challenges. Firstly, it represents a novel analysis for breast pathologists. Secondly, the heterogeneity of PD-L1 expression in mTNBC further complicates the assessment. Lastly, the lack of standardized assays and staining platforms adds to the complexity. In KEYNOTE trials, PD-L1 expression was evaluated using the IHC 22C3 pharmDx kit as a companion diagnostic test. However, both the 22C3 pharmDx and VENTANA PD-L1 (SP263) assays are validated for CPS assessment. Consequently, assay-platform choice, staining conditions, and scoring methods can significantly impact the testing outcomes. This consensus paper aims to discuss the intricacies of PD-L1 CPS testing in mTNBC and provide practical recommendations for pathologists. Additionally, we present findings from a nationwide Italian survey elucidating the state-of-the-art in PD-L1 CPS testing in mTNBC.

Clinical, histological, immunohistochemical, and biomolecular analysis of hyaluronic acid in early wound healing of human gingival tissues: A randomized, split-mouth trial

BACKGROUND

Hyaluronic acid (HA) exerts a fundamental role in tissue repair. In vitro and animal studies demonstrated its ability to enhance wound healing. Nevertheless, in vivo human studies evaluating mechanisms involved in oral soft tissue repair are lacking. The aim of this study was to evaluate the in vivo effect of HA on early wound healing of human gingival (G) tissues.

METHODS

In the present randomized, split-mouth, double-blind, clinical trial, G biopsies were obtained in eight patients 24 h post-surgery after HA application (HA group) and compared with those obtained from the same patients without HA application (no treatment; NT group). Clinical response was evaluated through the Early Wound Healing Score (EHS). Microvascular density (MVD), collagen content and cellular proliferation were evaluated through sirius red and Masson trichrome staining, and Ki-67 immunohistochemistry, respectively. To assess collagen turnover, MMP-1, MMP-2, MMP-9, TGF-β1 protein levels and LOX, MMP1, TIMP1, TGFB1 gene expression were analyzed by western blot and real time polymerase chain reaction.

RESULTS

Twenty-four hours after surgery, the EHS was significantly higher in the HA group. MVD, collagen content, and cell proliferation were not affected. LOX mRNA, MMP-1 protein, and TIMP1 gene expression were significantly upregulated in the HA compared to the NT group.

CONCLUSIONS

The additional use of 0.8% HA gel does not modify new blood vessel growth in the early phase of gingival wound healing. Concerning the secondary outcomes, HA seems to enhance extracellular matrix remodeling and collagen maturation, which could drive early wound healing of G tissues to improve clinical parameters.

Separation and single-cell analysis for free gastric cancer cells in ascites and peritoneal lavages based on microfluidic chips

BACKGROUNDS

Detecting free cancer cells from ascites and peritoneal lavages is crucial for diagnosing gastric cancer (GC). However, traditional methods are limited for early-stage diagnosis due to their low sensitivity.

METHODS

A label-free, rapid, and high-throughput technique was developed for separating cancer cells from ascites and peritoneal lavages using an integrated microfluidic device, taking advantage of dean flow fractionation and deterministic lateral displacement. Afterward, separated cells were analyzed using a microfluidic single-cell trapping array chip (SCTA-chip). In situ immunofluorescence for EpCAM, YAP-1, HER-2, CD45 molecular expressions, and Wright-Giemsa staining were performed for cells in SCTA-chips. At last, YAP1 and HER-2 expression in tissues was analyzed by immunohistochemistry.

FINDINGS

Through integrated microfluidic device, cancer cells were successfully separated from simulated peritoneal lavages containing 1/10,000 cancer cells with recovery rate of 84.8% and purity of 72.4%. Afterward, cancer cells were isolated from 12 patients' ascites samples. Cytological examinations showed cancer cells were efficiently enriched with background cells excluded. Afterwards, separated cells from ascites were analyzed by SCTA-chips, and recognized as cancer cells through EpCAM⁺/CD45^- expression and Wright-Giemsa staining. Interestingly, 8 out of 12 ascites samples showed HER-2⁺ cancer cells. At last, the results through a serial expression analysis showed that YAP1 and HER-2 have discordant expression during metastasis.

INTERPRETATION

Microfluidic Chips developed in our study could not only rapidly detect label-free free GC cells in ascites and peritoneal lavages with high-throughput, they could also analyze ascites cancer cells at the single-cell level, improving peritoneal metastasis diagnosis and investigation of therapeutic targets.

FUNDING

This research was supported by National Natural Science Foundation of China (22134004, U1908207, 91859111); Natural Science Foundation of Shandong Province of China (ZR2019JQ06); Taishan Scholars Program of Shandong Province tsqn (201909077); Local Science and Technology Development Fund Guided by the Central Government (YDZX20203700002568); Applied Basic Research Program of Liaoning Province (2022020284-JH2/1013).

A Standardized Pathology Report for Gastric Cancer: 2nd Edition

The first edition of 'A Standardized Pathology Report for Gastric Cancer' was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

Current molecular biomarkers evaluation in gastric/gastroesophageal junction adenocarcinoma: pathologist does matter

The comprehensive molecular characterization of gastric and gastroesophageal junction adenocarcinomas has led to the improvement of targeted and more effective treatments. As a result, several biomarkers have been introduced into clinical practice and the implementation of innovative diagnostic tools is under study. Such assessments are mainly based on the evaluation of limited biopsy material in clinical practice. In this setting, the pathologist represents a key player in the selection of patients facilitating precision medicine approaches.

A standardized pathology report for gastric cancer: 2nd edition

The first edition of 'A Standardized Pathology Report for Gastric Cancer' was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

Targeting HER2 in metastatic gastroesophageal adenocarcinomas: What is new?

Gastric and esophageal adenocarcinomas represent a biologically heterogeneous disease. The identification, in early eighties, of human epidermal growth factor receptor 2 (HER2) overexpression, being present in 12 to 20% of the cases, marked a major milestone in the efforts of unraveling the molecular complexity of this disease. This led to the development of anti-HER2-therapies, trastuzumab being the first to demonstrate, in combination with cisplatin and 5FU/capecitabine chemotherapy, an improvement in response rate and survival in the first-line setting of patients with metastatic, HER2-positive gastroesophageal adenocarcinomas. Afterwards, during a decade, several studies have tried new strategies either to block HER2 pathway differently or to combine different anti-HER2, without efficacy. Everything changed with studies demonstrating additive effect between anti-HER2 and immune checkpoint inhibitors and leading to phase III clinical trials combining anti-HER2 and anti-PD-L1/PD1 therapies. Pembrolizumab, a PD-1 inhibitor, was recently granted by FDA an accelerated approval, in patients with HER2-positive gastro-oesophageal adenocarcinomas, in combination with trastuzumab and platinum-based chemotherapy following meaningful improvement in overall response rate over standard treatment. Progression-free and overall-survival results are still awaited to change our first-line standard treatment. Furthermore, new HER2 inhibitors have been developed, blocking HER2-mediated pathway signaling via different mechanisms from pan-HER inhibition to anti-HER2 antibody drug conjugates with promising results in pretreated patients. Trastuzumab-deruxtecan has in particular showed interesting results in pretreated patients. We present here a review of the recent data and perspectives in HER2-positive metastatic gastroesophageal adenocarcinomas.

Molecular Pathology of Gastric Cancer

Gastric cancer (GC) is one of the most common lethal malignant neoplasms worldwide, with limited treatment options for both locally advanced and/or metastatic conditions, resulting in a dismal prognosis. Although the widely used morphological classifications may be helpful for endoscopic or surgical treatment choices, they are still insufficient to guide precise and/or personalized therapy for individual patients. Recent advances in genomic technology and high-throughput analysis may improve the understanding of molecular pathways associated with GC pathogenesis and aid in the classification of GC at the molecular level. Advances in next-generation sequencing have enabled the identification of several genetic alterations through single experiments. Thus, understanding the driver alterations involved in gastric carcinogenesis has become increasingly important because it can aid in the discovery of potential biomarkers and therapeutic targets. In this article, we review the molecular classifications of GC, focusing on The Cancer Genome Atlas (TCGA) classification. We further describe the currently available biomarker-targeted therapies and potential biomarker-guided therapies. This review will help clinicians by providing an inclusive understanding of the molecular pathology of GC and may assist in selecting the best treatment approaches for patients with GC.

HER2 in Metastatic Colorectal Cancer: Pathology, Somatic Alterations, and Perspectives for Novel Therapeutic Schemes

HER2 is an emerging biomarker in colorectal cancer (CRC). This oncogene plays an essential role in regulating cell proliferation, differentiation, migration, and, more in general, tumorigenesis and tumor progression. The most frequent types of HER2 alterations in CRC include gene amplification and missense mutations in 7-8% of CRC, often being mirrored by HER2 protein overexpression, representing founder events in solid tumors, including CRC. There are currently no approved HER2-targeted therapy guidelines for CRC; however, several studies have shown that HER2 can be effectively targeted in meta-static CRC settings. In this review, we discuss the current knowledge of HER2 testing in CRC and the immediate future perspectives for HER2 targeting in the metastatic setting.

Expression of hepatocyte nuclear factor 4 alpha, wingless-related integration site, and β-catenin in clinical gastric cancer

BACKGROUND

Gastric cancer (GC) is the second most common cause of cancer-related deaths worldwide. Hepatocyte nuclear factor 4 alpha (HNF4α) that belongs to the nuclear hormone receptor superfamily, is overexpressed in GC tissues, and might be involved in the development of GC by regulating its downstream wingless-related integration site (WNT)/β-catenin signaling.

AIM

To clarify the expression of HNF4α/WNT5a/β-catenin signaling proteins in clinical GC tissues.

METHODS

We immunohistochemically stained pathological blocks of GC and matched para-cancerous tissues. The intensity of HNF4α, WNT5a and β-catenin staining in the tumor cells was determined according to cell rates and staining intensity. The correlations between GC and HNF4α, WNT5a, and β-catenin expression using chi-square and paired chi-square tests. Relationships between double-positive HNF4α and WNT5a expression and types of gastric tumor tissues were assessed using regression analysis. Correlations between HNF4α and WNT5a expression at the RNA level in GC tissues found in the TCGA database were analyzed using Pearson correlation coefficients.

RESULTS

We found more abundant HNF4α and WNT5a proteins in GC, especially in mucinous adenocarcinoma and mixed GC than in adjacent tissues (P < 0.001). Low and high levels of cytoplasmic β-catenin respectively expressed in GC and adjacent tissues (P < 0.001) were not significantly associated with pathological parameters.

CONCLUSION

The expressions of HNF4α and WNT5a could serve as early diagnostic biomarkers for GC.

HER2 Low, Ultra-low, and Novel Complementary Biomarkers: Expanding the Spectrum of HER2 Positivity in Breast Cancer

HER2 status in breast cancer is assessed to select patients eligible for targeted therapy with anti-HER2 therapies. According to the American Society of Clinical Oncology (ASCO) and College of American Pathologists (CAP), the HER2 test positivity is defined by protein overexpression (score 3+) at immunohistochemistry (IHC) and/or gene amplification at in situ hybridization (ISH). The introduction of novel anti-HER2 compounds, however, is changing this paradigm because some breast cancers with lower levels of protein expression (i.e. score 1+/2+ with no gene amplification) benefited from HER2 antibody-drug conjugates (ADC). Recently, a potential for HER2 targeting in HER2 "ultra-low" (i.e. score 0 with incomplete and faint staining in ≤10% of tumor cells) and MutL-deficient estrogen receptor (estrogen receptor)-positive/HER2-negative breast cancers has been highlighted. All these novel findings are transforming the traditional dichotomy of HER2 status and have dramatically raised the expectations in this field. Still, a more aware HER2 status assessment coupled with the comprehensive characterization of the clinical and molecular features of these tumors is required. Here, we seek to provide an overview of the current state of HER2 targeting in breast cancers beyond the canonical HER2 positivity and to discuss the practical implications for pathologists and oncologists.

ctDNA analysis in the personalized clinical management of gastroesophageal adenocarcinoma: turning hope into reality

Gastroesophageal adenocarcinoma (GEA) is a global health issue with a high fatality-to-case ratio and a 5-year overall survival that has only slightly improved. High-throughput molecular profiling has uncovered a profound complexity and heterogeneity in GEA biology, which limits considerably the treatment advances. Liquid biopsy with circulating tumor (ct)DNA analysis could elucidate GEA molecular heterogeneity and provide diagnostic, prognostic and predictive information to guide clinical decision-making. However, only a handful of studies have shown positive results for the application of ctDNA analysis in GEA clinical management. As a result, no comprehensive information is available to date on this continuously evolving topic. Here, we discuss the current state of knowledge, along with promises and challenges related to ctDNA analysis in GEA.

Biomarker-targeted therapies for advanced-stage gastric and gastro-oesophageal junction cancers: an emerging paradigm

Advances in cancer biology and sequencing technology have enabled the selection of targeted and more effective treatments for individual patients with various types of solid tumour. However, only three molecular biomarkers have thus far been demonstrated to predict a response to targeted therapies in patients with gastric and/or gastro-oesophageal junction (G/GEJ) cancers: HER2 positivity for trastuzumab and trastuzumab deruxtecan, and microsatellite instability (MSI) status and PD-L1 expression for pembrolizumab. Despite this lack of clinically relevant biomarkers, distinct molecular subtypes of G/GEJ cancers have been identified and have informed the development of novel agents, including receptor tyrosine kinase inhibitors and monoclonal antibodies, several of which are currently being tested in ongoing trials. Many of these trials include biomarker stratification, and some include analysis of circulating tumour DNA (ctDNA), which both enables the noninvasive assessment of biomarker expression and provides an indication of the contributions of intratumoural heterogeneity to response and resistance. The results of these studies might help to optimize the selection of patients to receive targeted therapies, thus facilitating precision medicine approaches for patients with G/GEJ cancers. In this Review, we describe the current evidence supporting the use of targeted therapies in patients with G/GEJ cancers and provide guidance on future research directions.

Cancer Immunoprevention: Current Status and Future Directions

Cancer is one of the most serious diseases affecting health and the second leading cause of death worldwide. Despite the development of various therapeutic modalities to deal with cancer, limited improvement in overall survival of patients has been yielded. Since there is no certain cure for cancer, detection of premalignant lesions, and prevention of their progression are vital to the decline of high morbidity and mortality of cancer. Among approaches to cancer prevention, immunoprevention has gained further attention in recent years. Deep understanding of the tumor/immune system interplay and successful prevention of virally-induced malignancies by vaccines have paved the way toward broadening cancer immunoprevention application. The identification of tumor antigens in premalignant lesions was the turning point in cancer immunoprevention that led to designing preventive vaccines for various malignancies including multiple myeloma, colorectal, and breast cancer. In addition to vaccines, immune checkpoint inhibitors are also being tested for the prevention of oral squamous cell carcinoma (SCC), and imiquimod which is an established drug for the prevention of skin SCC, is a non-specific immunomodulator. Herein, to provide a bench-to-bedside understanding of cancer immunoprevention, we will review the role of the immune system in suppression and promotion of tumors, immunoprevention of virally-induced cancers, identification of tumor antigens in premalignant lesions, and clinical advances of cancer immunoprevention.

Comparing human epidermal growth factor receptor 2 amplification and expression using immunohistochemistry and silver in situ hybridisation in gastric carcinoma and lymph node metastasis

Detecting the amplification and expression of human epidermal growth factor receptor (HER2) is important for planning trastuzumab treatment for patients with gastric carcinoma. The present study aimed to analyse HER2 amplification and expression in primary gastric adenocarcinoma tumours and metastatic lymph nodes using microarray methods, and to assess the potential contribution of these methods to treatment planning. In total, 60 patients with lymph node metastasis were included in the present study. Microarray blocks were obtained from the tissue blocks of primary tumours and metastatic lymph nodes. HER2 expression and amplification were investigated using immunohistochemical and silver in situ hybridisation (SISH) methods, respectively. Following immunohistochemical evaluation of HER2 in primary tumours, the sensitivity and specificity of the microarray method relative to the single block method were 69 and 100%, respectively. For HER2 detection in microarray block sections from primary tumours, the sensitivity and specificity of the SISH method relative to immunohistochemistry were 56 and 100%, respectively. When using SISH in microarray blocked sections, there was a high degree of concordance (98% concordance rate) between HER2 amplification in the primary tumour and the metastatic lymph node. Furthermore, the sensitivity and specificity of metastatic lymph node results relative to those of the primary tumour were 100 and 98%, respectively. Overall, the single block method was more reliable compared with the microarray method for planning treatment. When microarray blocking was used, a large number of samples must be tested to ensure reliable results. The immunohistochemical method is recommended as the first step as SISH alone increases the risk of false-negative results. Assessing HER2 amplification for treatment planning would be beneficial for primary tumours, as well as metastatic lymph nodes.

Columnar Cell Lesion and Apocrine Hyperplasia of the Breast: Is There a Common Origin? The Role of Prolactin-induced Protein

Noninvasive breast lesions encompass a heterogeneous group of risk indicators and nonobligate precursors of breast cancer, such as apocrine hyperplasia (AH) and columnar cell lesions (CCLs). Given the different expression of ER and ER-regulated genes in AH and CCL, these two alterations are currently considered discrete conditions. However, whether they share early biologic changes is not clear to date. Here, we sought to define the clinicopathologic and immunohistochemical features of a prospective series of combined lesions made up by CCLs and AH forming a continuum within single terminal duct-lobular units. The study group included 19 cases, whereas 25 cases of synchronous contiguous CCLs and AH served as control group. The different components of each case were subjected to immunohistochemical analysis for ER, PR, AR, HER2, BCL2, CCND1, MUC1, and PIP. Although CCLs and AHs arising in continuity showed opposite patterns of ER expression, the PIP-positive apocrine signature was consistently present in both components. In conclusion, apocrine changes are highly recurrent in CCLs growing within foci of AH, regardless of the ER activation. Our results suggest that PIP-positive and PIP-negative CCLs are likely to represent biologically distinct conditions and that apocrine changes might occur earlier than ER activation in the natural history of breast precursor lesions.

HER2 Heterogeneity in Personalized Therapy of Gastro-Oesophageal Malignancies: An Overview by Different Methodologies

Human epidermal growth factor receptor-2 (HER2)-expression gastro-oesophageal adenocarcinomas (GEA) gained interest as an important target for therapy with trastuzumab. In the current review, we focused the current knowledge on HER2 status in dysplastic and neoplastic gastric conditions, analyzing the methodological procedures to identify HER2 expression/amplification, as well as the proposed scoring recommendations. One of the most relevant questions to evaluate the useful impact of HER2 status on therapeutic choice in GEAs is represented by the significant heterogeneity of HER2 protein and gene expression that may affect the targeted treatment selection. Future development of biotechnology will continue to evolve in order to offer more powerful detection systems for the assessment of HER2 status. Finally, liquid biopsy as well as mutation/amplification of several additional genes may furnish an early detection of secondary HER2 resistance mechanisms in GEAs with a better monitoring of the treatment response.

PSCA is a target of chimeric antigen receptor T cells in gastric cancer

Background

Gastric cancer is a deadly malignancy and is a prognostically unfavorable entity with restricted therapeutic strategies available. Prostate stem cell antigen (PSCA) is a glycosylphosphatidylinositol (GPI)-anchored cell surface protein widely expressed in bladder, prostate, and pancreatic cancers. Existing studies have thoroughly recognized the availability of utilizing anti-PSCA CAR-T cells in the treatment of metastatic prostate cancer and non-small-cell lung cancer. However, no previous study has investigated the feasibility of using anti-PSCA CAR-T cells to treat gastric cancer, irrespective of the proven expression of PSCA on the gastric cancer cell surface.

Methods

We determined the expression of PSCA in several primary tumor tissues and constructed third-generation anti-PSCA CAR-T cells. We then incubated anti-PSCA CAR-T cells and GFP-T cells with target tumor cell lines at E:T ratios of 2:1, 1:1, 1:2, and 1:4 to evaluate the therapeutic efficacy of anti-PSCA CAR-T cells in vitro. We also assayed canonical T cell activation markers after coculturing anti-PSCA CAR-T cells with target cell lines by flow cytometry. The detection of a functional cytokine profile was carried out via enzyme-linked immunosorbent assays. We then evaluated the antitumor activity of anti-PSCA CAR-T cells in vivo by establishing two different xenograft GC mouse models.

Results

Anti-PSCA CAR-T cells exhibited upregulated activation markers and increased cytokine production profiles related to T cell cytotoxicity in an antigen-dependent manner. Moreover, anti-PSCA CAR-T cells exhibited robust anti-tumor cytotoxicity in vitro. Importantly, we demonstrated that anti-PSCA CAR-T cells delivered by peritumoral injection successfully stunted tumor progression in vivo. However, intravenous administration of anti-PSCA CAR-T cells failed to reveal any therapeutic improvements.

Conclusions

Our findings corroborated the feasibility of anti-PSCA CAR-T cells and their efficacy against gastric cancer, implicating the potential of applying anti-PSCA CAR-T cells to treat GC patients in the clinic.

Evaluation of Intratumoral and Intertumoral Heterogeneity of MET Protein Expression in Gastric Cancer

Tumor heterogeneity of a target molecule could contribute to failure of the targeted therapy. We investigated the heterogeneity of MET expression within same primary gastric cancer (GC) and between primary and corresponding secondary GC lesions using immunohistochemistry (IHC). Intratumoral heterogeneity was defined as discordant MET status among 3 tissue microarray cores (3 different areas of same tumor). IHC 3+ was considered positive for MET overexpression. MET overexpression was observed in 2.7% (50/1869) of all examined cores and 5.3% (33/623) of primary GCs. When we compared MET IHC results between 3 cores from each tumor, intratumoral heterogeneity was identified (65.0% in total 623 cases; 84.4% in 480 cases with any staining intensity; 84.9% in 251 cases with moderate to strong intensity; 90.9% in 33 cases with strong intensity). Of 33 MET-overexpressed GCs, the average proportion of strongly stained area was 19.6% in the whole sections. Of 269 cases with primary GC and regional lymph node metastasis, 17 (6.3%) showed MET positivity in which 9 (52.9%) were discordant (negative conversion). In 123 cases with primary and corresponding local recurrent/distant metastatic GC, 3 (2.4%) showed MET positivity in which 2 (66.7%) were discordant (positive conversion). In the survival analysis, MET IHC 3+ in lymph node metastases was an independent negative prognostic factor for overall survival. We found that MET overexpression is uncommon and highly heterogeneous in GC. This severe heterogeneity of MET status should be considered in tissue sampling and development of biomarkers for anti-MET therapy.

Automated segmentation of cell membranes to evaluate HER2 status in whole slide images using a modified deep learning network

The uncontrollable growth of cells in the breast tissue causes breast cancer which is the second most common type of cancer affecting women in the United States. Normally, human epidermal growth factor receptor 2 (HER2) proteins are responsible for the division and growth of healthy breast cells. HER2 status is currently assessed using immunohistochemistry (IHC) as well as in situ hybridization (ISH) in equivocal cases. Manual HER2 evaluation of IHC stained microscopic images involves an error-prone, tedious, inter-observer variable, and time-consuming routine lab work due to diverse staining, overlapped regions, and non-homogeneous remarkable large slides. To address these issues, digital pathology offers reproducible, automatic, and objective analysis and interpretation of whole slide image (WSI). In this paper, we present a machine learning (ML) framework to segment, classify, and quantify IHC breast cancer images in an effective way. The proposed method consists of two major classifying and segmentation parts. Since HER2 is associated with tumors of an epithelial region and most of the breast tumors originate in epithelial tissue, it is crucial to develop an approach to segment different tissue structures. The proposed technique is comprised of three steps. In the first step, a superpixel-based support vector machine (SVM) feature learning classifier is proposed to classify epithelial and stromal regions from WSI. In the second stage, on classified epithelial regions, a convolutional neural network (CNN) based segmentation method is applied to segment membrane regions. Finally, divided tiles are merged and the overall score of each slide is evaluated. Experimental results for 127 slides are presented and compared with state-of-the-art handcraft and deep learning-based approaches. The experiments demonstrate that the proposed method achieved promising performance on IHC stained data. The presented automated algorithm was shown to outperform other approaches in terms of superpixel based classifying of epithelial regions and segmentation of membrane staining using CNN.

Mismatch Repair Protein Loss as a Prognostic and Predictive Biomarker in Breast Cancers Regardless of Microsatellite Instability

Background

Breast cancers that harbor mismatch-repair (MMR) deficiency and/or microsatellite instability (MSI) might be sensitive to immune checkpoint blockade, but there are currently no specific guidelines for assessing MMR status in breast cancer. Here, we sought to define the clinical value of MMR immunohistochemistry (IHC) and MSI analysis in breast cancers.

Methods

We subjected 444 breast cancers to MMR IHC and MSI analysis. Cases were classified as MMR-proficient (pMMR), MMR-deficient (dMMR), and MMR-heterogeneous (hMMR) based on the loss of immunoreactivity; MSI was defined by instability in the five indicators recommended by the National Cancer Institute for endometrial and colorectal cancers. Correlation of MMR status with patients' survival was assessed using the Kaplan-Meier estimator. Statistical tests were two-sided.

Results

Loss of MMR proteins was homogeneous (dMMR) in 75 patients (17%) and heterogeneous (hMMR) in 55 (12%). Among luminal breast cancers, there were similar frequencies of dMMR and hMMR tumors. Overall, the rate of discrepancy between IHC and MSI analysis was high (91%). Women with Luminal B-like dMMR carcinomas (n = 44) showed shorter overall survival (median = 77 months, range = 0-115 months) than those with pMMR (n = 205) or hMMR (n = 35) tumors (median = 84 months, range = 0-127 months) (P = .008). On the contrary, patients with estrogen receptor-negative breast cancers treated with chemotherapy lived longer in cases of dMMR (n = 9) than pMMR (n = 33) or hMMR (n = 7) tumors, with 87 months of median survival (range = 73-123 months) for the former compared with 79 months (range = 8-113 months) for the latter two categories (P < .001).

Conclusions

Immunohistochemistry and MSI are not interchangeable tests in breast carcinomas. MMR protein loss is a more common event than MSI and shows intra-tumor heterogeneity. MMR IHC allows the identification of clinically relevant subclasses of breast cancer patients, provided that multiple areas of the tumor are analyzed.

Molecular and Immunohistochemical Markers with Prognostic and Predictive Significance in Liver Metastases from Colorectal Carcinoma

Despite the significant recent achievements in the diagnosis and treatment of colorectal cancer (CRC), the prognosis of these patients has currently plateaued. During the past few years, the opportunity to consider multiple treatment modalities (including surgery and other locoregional treatments, systemic therapy, and targeted therapy) led to the research of novel prognostic and predictive biomarkers in CRC liver metastases (CRCLM) patients. In this review, we seek to describe the current state of knowledge of CRCLM biomarkers and to outline impending clinical perspectives, in particular focusing on the cutting-edge tools available for their characterization.

The dynamics of HER2 status in esophageal adenocarcinoma

Trastuzumab, a monoclonal antibody against HER2, has become standard of care for metastatic HER2-overexpressing esophagogastric adenocarcinoma and is currently investigated as (neo)adjuvant treatment option in HER2-positive esophagogastric adenocarcinoma. The HER2 status is commonly determined on archived material of the primary tumor. However, this status may change over the course of treatment or disease progression. The aim of this study was to assess the dynamics of HER2 status in esophageal adenocarcinoma (EAC) in patients with resectable and recurrent disease, and to determine the associations of these changes with clinical outcome. Discordance, defined as any change in HER2 status between matched biopsy and post-neoadjuvant chemoradiation therapy resection specimen (N = 170), or between matched resection specimen and recurrence of patients not eligible for curative treatment (N = 61), was determined using the standardized HER2 status scoring system. Clinically relevant positive discordance was defined as a change to HER2 positive status, as this would imply eligibility for HER2-targeted therapy. A difference in HER2 status between biopsy and resection specimen and resection specimen and metachronous recurrence was observed in 2.1% (n = 3) and 3.3% (n = 2) of the paired cases, respectively. Clinically relevant discordance was detected in 1.4% (n = 2) of the resectable patients and 1.6% (n = 1) of the patients with recurrent disease. Patients with HER2-positive status tumors before start of neoadjuvant treatment showed better overall survival, but not statistically significant. No association between HER2 status discordance and survival was found. Clinically relevant HER2 status discordance was observed and in order to prevent under-treatment of patients, the assessment of HER2 status in the metastatic setting should preferably be performed on the most recently developed lesions if the previous HER2 assessment on archival material of the primary tumor was negative.

Her2Net: A Deep Framework for Semantic Segmentation and Classification of Cell Membranes and Nuclei in Breast Cancer Evaluation

We present an efficient deep learning framework for identifying, segmenting, and classifying cell membranes and nuclei from human epidermal growth factor receptor-2 (HER2)-stained breast cancer images with minimal user intervention. This is a long-standing issue for pathologists because the manual quantification of HER2 is error-prone, costly, and time-consuming. Hence, we propose a deep learning-based HER2 deep neural network (Her2Net) to solve this issue. The convolutional and deconvolutional parts of the proposed Her2Net framework consisted mainly of multiple convolution layers, max-pooling layers, spatial pyramid pooling layers, deconvolution layers, up-sampling layers, and trapezoidal long short-term memory (TLSTM). A fully connected layer and a softmax layer were also used for classification and error estimation. Finally, HER2 scores were calculated based on the classification results. The main contribution of our proposed Her2Net framework includes the implementation of TLSTM and a deep learning framework for cell membrane and nucleus detection, segmentation, and classification and HER2 scoring. Our proposed Her2Net achieved 96.64% precision, 96.79% recall, 96.71% F-score, 93.08% negative predictive value, 98.33% accuracy, and a 6.84% false-positive rate. Our results demonstrate the high accuracy and wide applicability of the proposed Her2Net in the context of HER2 scoring for breast cancer evaluation.

HER2 is frequently overexpressed in hepatoid adenocarcinoma and gastric carcinoma with enteroblastic differentiation: a comparison of 35 cases to 334 gastric carcinomas of other histological types

AIMS

α-Fetoprotein (AFP)-producing gastric carcinoma (AFPGC) is one of the most aggressive GC subtypes. Frequent expression of human epidermal growth factor receptor 2 (HER2) has previously been reported in hepatoid adenocarcinoma (HAC), a major histological subtype of AFPGC originating from common-type GC (CGC). However, HER2 expression levels in other AFPGC histological subtypes are unknown. In this study, we analysed HER2 expression in GCs with primitive phenotypes in addition to HAC.

METHODS

HER2 expression was evaluated in representative complete sections from 16 HACs, 19 GCs with enteroblastic differentiation (GCEDs) and 334 GCs of other histological types as controls. The Ruschoff/Hofmann method was used to score HER2 immunohistochemistry. Samples with a HER2 score of 2+ were further assessed using fluorescence in situ hybridisation. Oncofetal protein (OFP) expression in HAC and GCED was tested via immunohistochemical staining for AFP, glypican 3 and Sal-like protein 4.

RESULTS

Thirty of 35 HAC/GCED cases comprised more than two histological patterns. The HER2 positivity rates of each histological component in the HACs/GCEDs were 25.0% for HAC (n=16), 34.6% for GCED (n=26) and 48.1% for CGC (n=27), which were higher than those of the control group (13.8%). Additionally, the majority of CGC components in HACs/GCEDs were positive for OFP (88.9%).

CONCLUSIONS

HER2 is frequently overexpressed not only in HAC but also in GCED and CGC components of HACs/GCEDs, which suggests an association between HER2 and OFP expression. Moreover, our findings suggest that HER2-positive CGC has a higher risk of progression to HAC/GCED than HER2-negative GC.

Building Up a High-throughput Screening Platform to Assess the Heterogeneity of HER2 Gene Amplification in Breast Cancers

Targeted therapies against the human epidermal growth factor receptor 2 (HER2) have radically changed the outcome of patients with HER2-positive breast cancers. However, a minority of cases displays a heterogeneous distribution of HER2-positive cells, which generates major clinical challenges. To date, no reliable and standardized protocols for the characterization and quantification of HER2 heterogeneous gene amplification in large cohorts have been proposed. Here, we present a high-throughput methodology to simultaneously assess the HER2 status across different topographic areas of multiple breast cancers. In particular, we illustrate the laboratory procedure to construct enhanced tissue microarrays (TMAs) incorporating a targeted mapping of the tumors. All TMA parameters have been specifically optimized for the silver in situ hybridization (SISH) of formalin-fixed paraffin-embedded (FFPE) breast tissues. Immunohistochemical analysis of the prognostic and predictive biomarkers (i.e., ER, PR, Ki67, and HER2) should be performed using automated procedures. A customized SISH protocol has been implemented to allow a high-quality molecular analysis across multiple tissues that underwent different fixation, processing, and storage procedures. In this study, we provide a proof-of-principle that specific DNA sequences could be localized simultaneously in distinct topographic areas of multiple and heterogeneously processed breast cancers using an efficient and cost-effective method.

Digital Image Analysis of HER2 Immunostained Gastric and Gastroesophageal Junction Adenocarcinomas

Manual assessment of human epidermal growth factor receptor 2 (HER2) protein expression by immunohistochemistry (IHC) in gastric and gastroesophageal junction (GGEJ) adenocarcinomas is prone to interobserver variability and hampered by tumor heterogeneity and different scoring criteria. Equivocal cases are frequent, requiring additional in situ hybridization analysis. This study aimed to evaluate the accuracy of digital image analysis for the assessment of HER2 protein expression. In total, 110 GGEJ adenocarcinomas were included in tissue microarrays with 3 tissue cores per case. Two immunoassays, PATHWAY and HercepTest, and fluorescent in situ hybridization analysis were performed. The Visiopharm HER2-CONNECT Analysis Protocol Package was applied through the ONCOtopix digital image analysis software platform. HER2 membrane connectivity, calculated by the Analysis Protocol Package, was converted to standard IHC scores applying predetermined cutoff values for breast carcinoma as well as novel cutoff values. Cases with excessive cytoplasmic staining as well as HER2 amplified IHC negative cases were excluded from analysis. Applying HER2-CONNECT with connectivity cutoff values established for breast carcinoma resulted in 72.7% sensitivity and 100% specificity for the identification of HER2 positive gene amplified cases. By application of new cutoff values, the sensitivity increased to 100% without decreased specificity. With the new cutoff values, a 36% to 50% reduction of IHC equivocal cases was obtained. In conclusion, HER2-CONNECT with adjusted cutoff values seem to be an effective tool for standardized assessment of HER2 protein expression in GGEJ adenocarcinomas, decreasing the need for in situ hybridization analyzes.

Digital image analysis of HER2 immunohistochemistry in gastric- and oesophageal adenocarcinoma: a validation study on biopsies and surgical specimens

AIMS

To test the validity of diagnostics incorporating digital image analysis (DIA) for human epidermal growth factor 2 (HER2) immunohistochemistry (IHC) in gastro-oesophageal adenocarcinomas, as an alternative to current standard diagnostics using manual scoring.

METHODS AND RESULTS

We included 319 consecutive gastro-oesophageal adenocarcinomas (232 biopsies and 87 surgical specimens). DIA was applied to determine HER2 IHC classification, using both standard breast cancer (BC) and modified gastro-oesophageal cancer (GEC) cut-offs. Consensus manual scores were established by four independent observers. Chromogenic in-situ hybridization (CISH) was performed on all 2+ cases by manual scoring, DIA or both. HER2 status was considered positive in 3+ and CISH-positive 2+ cases. Overall agreement between DIA and consensus manual scores was 76.5% (weighted κ = 0.66, BC cut-offs) and 85.6% (weighted κ = 0.80, GEC cut-offs). Agreement was similar for biopsies and surgical specimens. All disagreement occurred in the manual IHC equivocal cases. DIA resulted in a reduction of 2+ cases: 75.8% with BC cut-offs and 46.5% with GEC cut-offs. HER2 status was positive in 48 cases (15%) with standard diagnostics and DIA using GEC cut-offs, and 46 cases (14.4%) using BC cut-offs (all with CISH in 2+ cases). Considering standard diagnostics as a reference, DIA showed 93.8% sensitivity and 99.6% specificity (BC cut-offs) or 97.9% sensitivity and 99.6% specificity (GEC cut-offs).

CONCLUSIONS

DIA is a reliable and feasible alternative to manual HER2 IHC scoring in gastro-oesophageal adenocarcinoma, both in biopsies and surgical specimens, leading to a reduction of 2+ cases for which subsequent ISH testing is required.

HER2 Heterogeneity in Gastroesophageal Cancer Detected by Testing Biopsy and Resection Specimens

CONTEXT

- In advanced gastric, esophageal, and gastroesophageal junction adenocarcinomas (GE-GEJ-AC) that overexpress ERBB2 (erb-b2 receptor tyrosine kinase 2 or HER2), anti-HER2 monoclonal antibody therapy confers survival benefit. To select patients for treatment, HER2 expression and gene amplification are evaluated by immunohistochemistry (IHC) and in situ hybridization.

OBJECTIVE

- To determine whether GE-GEJ-AC tested for HER2 on biopsy specimens of a primary tumor show different IHC scores and/or HER2 amplification by in situ hybridization in matched resection specimens, potentially changing therapy eligibility.

DESIGN

- Immunohistochemistry and silver in situ hybridization were performed in biopsy and/or resection specimens from 100 patients. HER2 testing was performed in matched resection and biopsy specimens of 15 cases to determine whether GE-GEJ-AC with IHC scores of 0, 1⁺, and 2⁺ in biopsy and resection specimens had different IHC and silver in situ hybridization results.

RESULTS

- The IHC 3⁺ cases showed HER2 amplification in 4 of 5 cases (80%), and IHC scores of 0, 1⁺, and 2⁺ showed 3.5%, 14.3%, and 23.5% HER2 amplification by silver in situ hybridization. Among the 15 paired biopsy and resection specimens, 9 (60%) had at least pT2 stage GE-GEJ-AC with HER2 IHC scores of 0, 1⁺, or 2⁺ in the biopsy, and 2 of those 9 cases (22%) had IHC 3⁺ and HER2 amplification by silver in situ hybridization on the resection specimen.

CONCLUSIONS

- Our data suggest that HER2 testing should be repeated on resection specimens of GE-GEJ-AC with HER2 IHC scores of negative (0 and 1⁺) or equivocal (2⁺) and in situ hybridization amplification negative biopsy specimen results to evaluate for HER2 heterogeneity when patients are being considered for anti-HER2 therapy.

Discordance in HER2 Status in Gastro-esophageal Adenocarcinomas: A Systematic Review and Meta-analysis

Trastuzumab combined with chemotherapy is standard of care for HER2 positive advanced gastro-esophageal cancers. The reported prevalence of HER2 discordance between primary tumors and corresponding metastases varies, hampering uniform patient selection for HER2 targeted therapy. This meta-analysis explores the influence of HER2 assessment methods on this discordance and investigates the prevalence of HER2 discordance in gastro-esophageal adenocarcinomas. PubMed, Embase and Cochrane databases were searched until January 2016. Differences in discordance rate between strict and broad(er) definitions of HER2 status were assessed using random-effect pair-wise meta-analysis. Random-effect single-arm meta-analyses were performed to assess HER2 discordance and the prevalence of positive and negative conversion. A significantly lower discordance rate in HER2 status between primary tumors and corresponding metastases was observed using a strict vs. broad definition of HER2 status (RR = 0.58, 95%CI 0.41-0.82), with a pooled discordance rate of 6.2% and 12.2%, respectively. Using the strict definition of HER2 assessment pooled overall discordance was 7% (95%CI 5-10%). The lowest discordance rates between primary tumors and corresponding metastasis are observed when using a strict method of HER2 positivity. Treatment outcomes of different studies will be better comparable if selection of eligible patients for HER2 targeted therapy is based on this strict definition.

Effect of neoadjuvant chemotherapy on HER-2 expression in surgically treated gastric and oesophagogastric junction carcinoma: a multicentre Italian study

Predictors of response to neoadjuvant chemotherapy are not available for gastric and oesophago-gastric junction carcinoma. HER-2 over-expression in breast cancer correlates with poor prognosis and high incidence of recurrence. First aim of this study was to evaluate if the HER-2 expression/amplification is predictive of response to neoadjuvant chemotherapy in terms of pathologic regression. Secondary aim was to evaluate if HER-2 expression varies after neoadjuvant treatment. Thirty-five patients with locally advanced gastric or oesophago-gastric junction carcinoma underwent preoperative chemotherapy and surgical resection at San Raffaele Scientific Institute and Spedali Civili of Brescia. HER-2 expression/amplification was evaluated on every biopsy at diagnosis time and on every surgical sample after neoadjuvant chemotherapy. Pathologic response to chemotherapy was evaluated according to TNM classification (ypT status and ypN status) and Mandard's tumour regression grade classification. In our series 10 patients (28.6%) showed a reduction in HER-2 overexpression and in 6 of them (17.1%) HER-2 expression completely disappeared. Only three of the six patients with HER-2 disappearance had a complete pathological response to neoadjuvant chemotherapy. There was a strong correlation between HER-2 negativity on biopsy and absence of lymph node metastasis in surgical samples after neoadjuvant chemotherapy, irrespective of nodal status before chemotherapy. A direct correlation between HER-2 reduction after neoadjuvant chemotherapy and pathologic regression (primary tumour and lymph nodes) in surgical samples was found. HER-2 negativity may represent a predictor of pathologic response to neoadjuvant chemotherapy for gastric and oesophago-gastric junction adenocarcinoma. Neoadjuvant treatment can reduce HER-2 overexpression.

HER2 Testing and Clinical Decision Making in Gastroesophageal Adenocarcinoma: Guideline From the College of American Pathologists, American Society for Clinical Pathology, and the American Society of Clinical Oncology

Context ERBB2 (erb-b2 receptor tyrosine kinase 2 or HER2) is currently the only biomarker established for selection of a specific therapy for patients with advanced gastroesophageal adenocarcinoma (GEA). However, there are no comprehensive guidelines for the assessment of HER2 in patients with GEA. Objectives To establish an evidence-based guideline for HER2 testing in patients with GEA, formalize the algorithms for methods to improve the accuracy of HER2 testing while addressing which patients and tumor specimens are appropriate, and to provide guidance on clinical decision making. Design The College of American Pathologists (CAP), American Society for Clinical Pathology (ASCP), and the American Society of Clinical Oncology (ASCO) convened an Expert Panel to conduct a systematic review of the literature to develop an evidence-based guideline with recommendations for optimal HER2 testing in patients with GEA. Results The Panel is proposing 11 recommendations with strong agreement from the open comment participants. Recommendations The Panel recommends that tumor specimen(s) from all patients with advanced GEA, who are candidates for HER2-targeted therapy, should be assessed for HER2 status before the initiation of HER2-targeted therapy. Clinicians should offer combination chemotherapy and an HER2-targeted agent as initial therapy for all patients with HER2-positive advanced GEA. For pathologists, guidance is provided for morphologic selection of neoplastic tissue, testing algorithms, scoring methods, interpretation and reporting of results, and laboratory quality assurance. Conclusion This guideline provides specific recommendations for assessment of HER2 in patients with advanced GEA while addressing pertinent technical issues and clinical implications of the results.

HER2 Testing and Clinical Decision Making in Gastroesophageal Adenocarcinoma: Guideline From the College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology

CONTEXT

- ERBB2 (erb-b2 receptor tyrosine kinase 2 or HER2) is currently the only biomarker established for selection of a specific therapy for patients with advanced gastroesophageal adenocarcinoma (GEA). However, there are no comprehensive guidelines for the assessment of HER2 in patients with GEA.

OBJECTIVES

- To establish an evidence-based guideline for HER2 testing in patients with GEA, to formalize the algorithms for methods to improve the accuracy of HER2 testing while addressing which patients and tumor specimens are appropriate, and to provide guidance on clinical decision making.

DESIGN

- The College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology convened an expert panel to conduct a systematic review of the literature to develop an evidence-based guideline with recommendations for optimal HER2 testing in patients with GEA.

RESULTS

- The panel is proposing 11 recommendations with strong agreement from the open-comment participants.

RECOMMENDATIONS

- The panel recommends that tumor specimen(s) from all patients with advanced GEA, who are candidates for HER2-targeted therapy, should be assessed for HER2 status before the initiation of HER2-targeted therapy. Clinicians should offer combination chemotherapy and a HER2-targeted agent as initial therapy for all patients with HER2-positive advanced GEA. For pathologists, guidance is provided for morphologic selection of neoplastic tissue, testing algorithms, scoring methods, interpretation and reporting of results, and laboratory quality assurance.

CONCLUSIONS

- This guideline provides specific recommendations for assessment of HER2 in patients with advanced GEA while addressing pertinent technical issues and clinical implications of the results.

HER2 Testing and Clinical Decision Making in Gastroesophageal Adenocarcinoma: Guideline From the College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology

CONTEXT

ERBB2 (erb-b2 receptor tyrosine kinase 2 or HER2) is currently the only biomarker established for selection of a specific therapy for patients with advanced gastroesophageal adenocarcinoma (GEA). However, there are no comprehensive guidelines for the assessment of HER2 in patients with GEA.

OBJECTIVES

To establish an evidence-based guideline for HER2 testing in patients with GEA, to formalize the algorithms for methods to improve the accuracy of HER2 testing while addressing which patients and tumor specimens are appropriate, and to provide guidance on clinical decision making.

DESIGN

The College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology convened an expert panel to conduct a systematic review of the literature to develop an evidence-based guideline with recommendations for optimal HER2 testing in patients with GEA.

RESULTS

The panel is proposing 11 recommendations with strong agreement from the open-comment participants.

RECOMMENDATIONS

The panel recommends that tumor specimen(s) from all patients with advanced GEA, who are candidates for HER2-targeted therapy, should be assessed for HER2 status before the initiation of HER2-targeted therapy. Clinicians should offer combination chemotherapy and a HER2-targeted agent as initial therapy for all patients with HER2-positive advanced GEA. For pathologists, guidance is provided for morphologic selection of neoplastic tissue, testing algorithms, scoring methods, interpretation and reporting of results, and laboratory quality assurance.

CONCLUSIONS

This guideline provides specific recommendations for assessment of HER2 in patients with advanced GEA while addressing pertinent technical issues and clinical implications of the results.

HER2 aberrations and heterogeneity in cancers of the digestive system: Implications for pathologists and gastroenterologists

Management of cancers of the digestive system has progressed rapidly into the molecular era. Despite the significant recent achievements in the diagnosis and treatment of these patients, the number of deaths for these tumors has currently plateaued. Many investigations have assessed the role of HER2 in tumors of the digestive system in both prognostic and therapeutic settings, with heterogeneous results. Novel testing and treatment guidelines are emerging, in particular in gastric and colorectal cancers. However, further advances are needed. In this review we provide a comprehensive overview of the current state-of-knowledge of HER2 alterations in the most common tumors of the digestive system and discuss the operational implications of HER2 testing.

HER2 heterogeneity in gastric/gastroesophageal cancers: From benchside to practice

HER2 is overexpressed in approximately 10%-20% of gastric and gastroesophageal junction carcinomas. In these types of cancer, accurate assessment of HER2 status is mandatory, for selecting patients who may benefit from targeted therapies with anti-HER2 drugs such as Trastuzumab. This manuscript focuses on HER2 in gastric carcinogenesis, on optimal evaluation of HER2 and on the possible causes which may contribute to inaccurate HER2 evaluation. Similarly to breast cancer HER2 evaluation, standardization of HER2 testing in gastric cancer is necessary in diagnostic practice. The three principle aspects which require consideration are: (1) the choice of sample with regards to cancer morphology - intestinal vs diffuse areas; (2) the choice of scoring criteria - use of HER2 scoring criteria specific for gastric cancer; and (3) the choice of HER2 evaluation methods - use of an algorithm in which both immunohistochemistry and in situ hybridization play a role. Problematic issues include: (1) pre-analytic variables with particular emphasis on fixation; (2) recommended methodology for HER2 assessment (immunohistochemistry vs in situ hybridization); (3) HER2 heterogeneity both within the primary tumor and between primary tumor and metastases; (4) reliability of biopsies in HER 2 evaluation; and (5) quantity of sample (FFPE blocks from surgical specimens or endoscopic biopsies) necessary for an adequate assessment.

Rediscovering Secondary Tumors of the Prostate in the Molecular Era

Metastatic involvement of the prostate from noncontiguous solid tumors is a rare event occurring by means of vascular dissemination. The reported cases of biopsy and surgical samples with metastatic involvement have increased; however, a comprehensive understanding of secondary tumors of the prostate is currently missing. Metastases to the prostate carry a dismal prognosis and may pose serious diagnostic challenges to both clinicians and pathologists, with crucial therapeutic implications. Secondary tumors of the prostate spread more frequently from the digestive tract, the lung, and the kidney. The integration of clinicoradiologic data with appropriate pathologic and immunohistochemical analyses is essential for the identification and the characterization of secondary tumors of the prostate, whereas molecular analyses could provide additional and complementary information, enabling precise diagnosis and appropriate clinical management. Patients with solitary metastases could benefit from prostatic resection and adjuvant therapy, whereas in cases of disseminated diseases, symptom control may be obtained with palliative procedures. The purpose of this review was to assess the current state of knowledge of secondary tumors involving the prostate gland and to discuss short-term future perspectives, while providing a practical approach to these uncommon conditions for pathologists and oncologists.

Effect of EGFR and p-AKT Overexpression on Chromosomal Instability in Gastric Cancer

BACKGROUND

Molecular profiling in gastric cancer (GC) is important for diagnosis and treatment. In this study, we investigated signal transduction pathways that might induce chromosomal instability in GC.

METHODS

Epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), and p-AKT expression were analyzed using immunohistochemistry, and chromosomal instability was assessed by DNA aneuploidy using laser scanning cytometry, in a total of 202 GC cases.

RESULTS

The rate of EGFR expression and p-AKT expression was 70.3 and 34.2 %, respectively, in GC patients. In total, 57.5 % of GC patients exhibited DNA aneuploidy, and p-AKT positively correlated with EGFR and HER2 (p = 0.0127 and p = 0.00031, respectively). Patients with EGFR overexpressing GC showed shorter disease-specific survival than the other cases (hazard ratio 2.00, 95 % confidence interval 1.19-3.53; p = 0.0104). Moreover, EGFR and p-AKT expression was significantly correlated with DNA aneuploidy (p = 0.0002 and p = 0.0302, respectively).

CONCLUSIONS

Our data showed that both EGFR and p-AKT overexpression were clearly associated with DNA aneuploidy. Aneuploidy could be a useful marker for therapies that target EGFR.

HER2 testing in paired biopsy and excision specimens of gastric cancer: the reliability of the scoring system and the clinicopathological factors relevant to discordance

BACKGROUND

Inclusion of trastuzumab in chemotherapy regimens is advantageous for patients with advanced or metastatic gastric cancer who overexpress HER2. Therefore, accurate assessment of HER2 status in tumor tissue is critical when weighing treatment options.

METHODS

We examined HER2 expression in 180 paired endoscopic biopsy and surgical excision specimens of gastric cancers via immunohistochemistry (IHC). Equivocal IHC results (IHC 2+) were resolved by HER2 fluorescence in situ hybridization (FISH). The relationships of several clinical and pathological features with discordant HER2 results in paired specimens were determined.

RESULTS

Fourteen biopsy specimens and surgical specimens (7.8%) were HER2-positive. Discordant HER2 IHC scores were observed in 90 paired specimens (50%) and 8 paired specimens (4.4%) had discordant results. The kappa coefficients for an HER2 diagnostic algorithm were 0.264, 0.339, and 0.690 for IHC scores, IHC categories, and final results, respectively (p < 0.001). Discordant HER2 results were significantly associated with discordant tumor differentiation in the paired biopsy and excision specimens (p = 0.01). Intratumoral heterogeneity did not predict HER2 discordance. There was no association between HER2 discordance and the number of biopsy tissue fragments (p = 0.764).

CONCLUSIONS

Hofmann's HER2 scoring system is a fairly reliable tool for evaluating HER2 status in biopsy and excision specimens. Discordant HER2 results in paired specimens were observed in a small percentage of gastric cancers. Testing all available specimens should be considered in order to eliminate discrepancies, especially when discordant tumor differentiation is observed.

The Contrasting Role of p16Ink4A Patterns of Expression in Neuroendocrine and Non-Neuroendocrine Lung Tumors: A Comprehensive Analysis with Clinicopathologic and Molecular Correlations

Lung cancer encompasses a constellation of malignancies with no validated prognostic markers. p16Ink4A expression has been reported in different subtypes of lung cancers; however, its prognostic value is controversial. Here, we sought to investigate the clinical significance of p16Ink4A immunoexpression according to specific staining patterns and its operational implications. A total of 502 tumors, including 277 adenocarcinomas, 84 squamous cell carcinomas, 22 large cell carcinomas, 47 typical carcinoids, 12 atypical carcinoids, 28 large cell neuroendocrine carcinomas, and 32 small cell carcinomas were reviewed and subjected to immunohistochemical analysis for p16Ink4A and Ki67. The spectrum of p16Ink4A expression was annotated for each case as negative, sporadic, focal, or diffuse. Expression at immunohistochemical level showed intra-tumor homogeneity, regardless tumor histotype. Enrichments in cells expressing p16Ink4A were observed from lower- to higher-grade neuroendocrine malignancies, whereas a decrease was seen in poorly and undifferentiated non-neuroendocrine carcinomas. Tumor proliferation indices were higher in neuroendocrine tumors expressing p16Ink4A while non-neuroendocrine malignancies immunoreactive for p16Ink4A showed a decrease in Ki67-positive cells. Quantitative statistical analyses including each histotype and the p16Ink4A status confirmed the independent prognostic role of p16Ink4A expression, being a high-risk indicator in neuroendocrine tumors and a marker of good prognosis in non-neuroendocrine lung malignancies. In this study, we provide circumstantial evidence to suggest that the routinary assessment of p16Ink4A expression using a three-tiered scoring algorithm, even in a small biopsy, may constitute a reliable, reproducible, and cost-effective substrate for a more accurate risk stratification of each individual patient.

HER2 Status in Premalignant, Early, and Advanced Neoplastic Lesions of the Stomach

Objectives. HER2 expression in gastric cancer (GC) has received attention as a potential target for therapy with Trastuzumab. We reviewed the current knowledge on HER2 status in premalignant gastric lesions and in early (EGC) and advanced (AGC) GC to discuss the possible pathogenetic and prognostic roles of HER2 overexpression in GC. Results. HER2 overexpression was documented in gastric low-grade (LG) and high-grade intraepithelial neoplasia (HG-IEN), with higher frequency in gastric type dysplasia. HER2 overexpression was significantly associated with disease recurrence and poor prognosis in EGC representing an independent risk factor for lymph node metastases. HER2 overexpression was more frequent in AGC characterized by high grade, advanced stage, and high Ki-67 labeling index. The discordance in HER2 status was evidenced between primitive GC and synchronous or metachronous metastases. Conclusions. HER2 overexpression in premalignant gastric lesions suggests its potential involvement in the early steps of gastric carcinogenesis. The assessment of HER2 status in EGC may be helpful for the identification of patients who are at low risk for developing nodal metastases. Finally, the possible discordance in HER2 status between primary GC and its synchronous metastases support routine assessment of HER2 both in the primary GC and in its metastatic lesions.

Serum HER2 extracellular domain as a potential alternative for tissue HER2 status in metastatic gastric cancer patients

AIM

We investigated whether serum concentrations of the HER2 extracellular domain (ECD) can be used as an alternative to test tissue HER2 status in metastatic gastric cancer.

MATERIALS & METHODS

A total of 133 cases of metastatic gastric cancer were included in present study. Serum HER2 ECD was measured by chemiluminescence immunoassay (CLIA). Receiver operating characteristic curve analysis was used to determine optimal serum HER2 ECD concentrations for differentiation between positive and negative HER2 status.

RESULTS

The median level of serum HER2 ECD was 9.6 ng/ml in metastatic gastric cancer patients. There was a significant relationship between serum and tissue levels of HER2 protein (p < 0.001). Area under the curve for serum HER2 ECD was 0.771 (95% CI: 0.682-0.860).

CONCLUSION

Levels of serum HER2 ECD are highly correlated with tissue HER2 status in metastatic gastric cancer. Serum HER2 ECD assay can be considered as a potential alternative for tissue HER2 status.

HER2 discordance between paired primary gastric cancer and metastasis: a meta-analysis

BACKGROUND

A number of studies have examined human epidermal growth factor receptor 2 (HER2) status in primary gastric cancer (GC) and associated metastasis, some showed their great concordance in HER2 expression, but others demonstrated notable discordance. There is still little consensus on HER2 discordance, therefore, a systematic review and meta-analysis was conducted to assess the status on HER2 discordance between primary GC and its paired metastasis.

METHODS

PubMed, EMBASE, ASCO and The Cochrane Library were searched for studies that explored the concordance between primary tumor and metastasis in patients with GC up to 10 March, 2014. Data of discordance of HER2 between primary GC and corresponding metastasis were extracted from the publications and random-effects models were used to estimate pooled discordance proportions.

RESULTS

Eighteen articles including 1,867 patients were included for the meta-analysis in accordance with the selection criteria. Pooled discordance proportions were 7% [95% confidence interval (CI): 5-10%] for HER2 status. Pooled proportions of tumors shifting from positive to negative and from negative to positive were 17% (95% CI: 7-29%) and 4% (95% CI: 2-6%) respectively. No publication bias was found in the meta-analysis.

CONCLUSIONS

The discordance of HER2 status is not rare in primary and metastatic GC through our meta-analysis. Prospective studies are needed to testify the clinical significance of the discordance of HER2 status.

HER2 testing in gastric and gastroesophageal adenocarcinomas

The human epidermal growth factor receptor 2 (HER2) is overexpressed in 10% to 35% of gastric and gastroesophageal junction (GEJ) adenocarcinomas. In 2010, the phase III Trastuzumab for Gastric Cancer (ToGA) trial showed that addition of the anti-HER2 monoclonal antibody trastuzumab to chemotherapy significantly improved survival of patients with advanced or metastatic tumors that were positive for HER2 overexpression. As a result, HER2 testing is now recommended for all patients with advanced or metastatic disease, although there is still some debate as to the optimal methods of assessment. HER2 expression in gastric and GEJ tumors shows several differences compared with breast tumors and, for this reason, the proposed criteria for scoring HER2 expression in biopsies and resections of gastric and GEJ carcinomas differ from those used in breast carcinomas. This review discusses what is currently known about the patterns of HER2 expression in gastric and GEJ adenocarcinomas, summarizes the findings of the ToGA trial and its clinical implications, and provides an overview of the recommended guidelines for the most accurate evaluation of HER2 status in gastric and GEJ cancer.

Minimum biopsy set for HER2 evaluation in gastric and gastro-esophageal junction cancer

BACKGROUND AND STUDY AIMS

The HER2 status of small endoscopic biopsies is important for predicting the eligibility of patients with metastatic HER2-positive gastric cancer or gastro-esophageal junction (GEJ) cancer for anti-HER2 therapy approved by the U.S. Food and Drug Administration. The aim of this study was to identify the minimum biopsy set required to evaluate the HER2 status with confidence.

PATIENTS AND METHODS

A total of 103 consecutive patients with resected gastric cancer or GEJ cancer were retrospectively selected; 2 formalin-fixed, paraffin-embedded samples of each surgical specimen and all paired endoscopic biopsies were analyzed for HER2 status with both immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) methods. A total of 10 virtual biopsies were constructed by selecting areas 2.6 mm in diameter on the luminal side of digitalized slides obtained from the surgical specimens. The results of evaluating HER2 status in virtual biopsies, slides containing complete surgical specimens, and endoscopic biopsies were compared. The resulting minimum biopsy set was applied to the endoscopic biopsy series for validation.

RESULTS

A biopsy set containing a minimum of 5 samples was identified as the most accurate in predicting HER2 status (sensitivity, 92 %; specificity, 97 %). In only 3 of the 103 cases (2.9 %) did a comparison of the HER2 evaluation of virtual biopsies and that of entire slides show inconsistent results. Overall agreement between the endoscopic biopsies and surgical samples for HER2 IHC status increased from 78.4 % to 92.3 % when biopsy sets containing 4 or fewer samples were compared with biopsy sets containing 5 or more samples.

CONCLUSIONS

Although the recommendations suggest that 8 to 10 biopsies are necessary, the results show that a minimum set of 5 biopsies may be sufficient for reliable HER2 assessment in gastric cancer and GEJ cancer. However, endoscopists should be aware that a smaller sample size may be less accurate in selecting patients eligible for anti-HER2 therapy.

Addition of all-trans-retinoic acid to omeprazole and sucralfate therapy improves the prognosis of gastric dysplasia

OBJECTIVE

To investigate the efficacy of all-trans retinoic acid (ATRA) in human gastric dysplasia.

METHODS

In this double-blind study, patients with precancerous gastric dysplasia with or without intestinal metaplasia (IM) received either conventional treatment consisting of omeprazole and sucralfate (control group) or conventional treatment plus ATRA. Gastric mucosal biopsies were performed before and after drug treatment and were analysed histologically; expression of retinoblastoma (Rb) protein and HER2 protein in gastric mucosa were measured using immunohistochemistry.

RESULTS

A total of 122 patients were included in the study, 63 in the ATRA group and 59 in the control group. In the ATRA group, dysplasia was attenuated in 43 out of 63 patients (68%) compared with 22 out of 59 patients (37%) in the control group; however, IM was not affected by treatment in either group. ATRA treatment was associated with significantly increased Rb expression and decreased HER2 expression in gastric mucosa.

CONCLUSIONS

The use of conventional therapy plus ATRA for gastric dysplasia was associated with improved efficacy compared with conventional therapy alone. It was also accompanied by increased Rb expression and decreased HER2 expression in gastric mucosa. The addition of ATRA to conventional therapy for gastritis may improve the prognosis of gastric dysplasia.