The validation of a novel method combining both HER2 immunohistochemistry and HER2 dual-colour silver in situ hybridization on one slide for gastric carcinoma testing

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.

Cathepsin L-induced galectin-1 may act as a proangiogenic factor in the metastasis of high-grade serous carcinoma

Background

New treatment options for metastasised high-grade serous carcinoma (HGSC) are urgently needed. HGSC frequently metastasises to the omentum, inducing angiogenesis in the local omental microvasculature to facilitate tumour growth. We previously showed that HGSC-secreted cathepsin L (CathL) induces pro-angiogenic changes in disease relevant human omental microvascular endothelial cells (HOMECs), suggesting a role in tumour angiogenesis. Here we investigate whether CathL acts by inducing local production of the carbohydrate-binding protein galectin-1 (Gal1), which has been reported to be involved in tumourigenesis in other tumours.

Methods

HOMECs were used for all experiments. Gal1 mRNA and protein levels were measured by RT-PCR and ELISA respectively. Gal1-induced cell proliferation was assessed using WST-1 assay, migration using a transwell assay and in vivo Gal1 expression by immunohistochemistry.

Results

CathL transcriptionally regulated HOMEC production and secretion of Gal1 via activation of NFκB (significantly inhibited by sulfasalazine). Gal1 significantly enhanced HOMEC migration (p < 0.001) and proliferation (p < 0.001), suggesting an autocrine action. The latter was significantly reduced by the MEK/ERK1/2 inhibitors U0126 and PD98059 suggesting downstream activation of this pathway. Immunohistochemical analysis of omenta from HGSC patients with or without metastatic disease demonstrated a positive correlation between Gal1 expression and number of microvessels (r = 0.8702, p < 0.001), and area of vessels (r = 0.7283, p < 0.001), supporting a proangiogenic role for Gal1 in omental metastases.

Conclusion

HOMEC Gal1 transcription and release in response to CathL secreted from metastasising HGSC acts in an autocrine manner on the local microvasculature to induce pro-angiogenic changes, highlighting a potential new therapeutic target.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1963-7) contains supplementary material, which is available to authorized users.

Methods and significance of the combined detection of HER2 gene amplification and chemosensitivity in gastric cancer

OBJECTIVE

This study aims to investigate the significance of combined detection of HER2 gene amplification and chemosensitivity in gastric cancer.

METHODS

Immunohistochemistry (IHC), fluorescence in situ hybridization (FISH) and fluorescence reverse-transcription polymerase chain reaction (RT-PCR) were used to analyze the expression of HER2 protein, HER2 gene amplification and the mRNA expression of ERCC1, TUBB3 and TYMS genes in 135 cases of gastric carcinoma.

RESULTS

The expression rate of HER2 protein was 39.3% (53/135). Among these positive cases, patients with HER2 protein (3+) accounted for 9.6% (13/135), patients with HER2 protein (2+) accounted for 13.3% (18/135), and patients with HER2 protein (1+) accounted for 16.3% (22/135). The amplification rate of the HER2 gene was 35.8% (19/53). In the detection of the mRNA expression of ERCC1, TUBB3 and TYMS, 45 patients had low and moderate single gene expression, 50 patients had low and moderate double gene expression, 22 patients had low and moderate mRNA expression for ERCC1, TUBB3 and TYMS, and 18 patients had no low and moderate expression. Among the 53 patients with HER2 protein expression and 22 patients with low and moderate mRNA expression of ERCC1, TUBB3 and TYMS, 12 patients received chemotherapy and trastuzumab. Follow-up results revealed that HER2 gene status was positively correlated with the therapeutic effect of the combined treatment in patients with low mRNA expression of ERCC1, TUBB3 and TYMS. Among these patients, five patients with extensive HER2 (3+), HER2 cluster-specific amplification, and low mRNA expression of ERCC1, TUBB3 and TYMS had a total survival of up to 19.1 months.

CONCLUSIONS

The detection of HER2 in gastric cancer is highly heterogeneity, and the combined detection of HER2 protein expression, HER2 gene amplification and chemosensitivity can provide important reference markers for the benefit of antitumor drugs.

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.

Human epidermal growth factor receptor 2 (HER-2) status evaluation in advanced gastric cancer using immunohistochemistry versus silver in situ hybridization

Accurate identification of human epidermal growth factor receptor 2 (HER-2) status in advanced gastric cancer patients is of utmost importance in terms of treatment planning. This study aimed to examine the HER-2 status in advanced gastric cancer patients using both immunohistochemistry (IHC) and silver in situ hybridization (SISH) techniques and to investigate concordance and diagnostic accuracy. In addition, associations between clinical parameters and HER 2 status were examined. A total of 313 patients diagnosed with locally advanced (Stage III: T3-4, N+) recurrent or metastatic adenocarcinoma of the stomach or esophagogastric junction, between 2009 and 2015, were included. HER-2 status was examined using both IHC and SISH techniques and the findings were compared. Overall SISH-confirmed HER-2 positivity rate was 22%. Multivariate analysis identified only well-differentiated tumor as a significant predictor of HER-2 positivity (OR: 2.9, 95% CI: 1.4-5.9, p = 0.003). When IHC 2+ and 3+ were considered positive for HER-2 status, sensitivity, specificity, and concordance rate (κ) was 95.7%, 93.8%, and 0.84, respectively. Corresponding figures when only IHC 3+ cases were considered positive were lower: 50%, 100%, and 0.61, respectively. The present method used for the identification of HER-2 positive gastric cancer patients provides satisfactory results. However, better categorization of IHC 2+ cases has the potential to improve the diagnostic accuracy, which is particularly important when more sophisticated methods are not readily available.

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.

Concordance rate between HER2 immunohistochemistry and in situ hybridization in gastric carcinoma: systematic review and meta-analysis

PURPOSE

The aim of this study was to investigate the diagnostic accuracy of HER2 immunohistochemistry (IHC) in gastric carcinoma (GC) through a systematic review, meta-analysis and diagnostic test accuracy review.

METHOD

The current study included 12,679 GC cases and 181 subsets in 45 eligible studies. We performed concordance analysis between HER2 IHC and in situ hybridization (ISH) in GC. Diagnostic test accuracy was analyzed and the area under the curve (AUC) on the summary receiver operating characteristic (SROC) curve was calculated.

RESULTS

HER2 amplification rates were 3.0%, 31.8%, and 93.0% in the IHC score 0/1+, 2+, and 3+ groups, respectively. The concordance rates between IHC and ISH were 0.969 (95% confidence interval [CI] 0.962-0.975), 0.393 (95% CI 0.331-0.458) and 0.915 (95% CI 0.882-0.939) in the HER2 IHC score 0/1+, 2+, and 3+ groups, respectively. For all the HER2 IHC score groups, the positive rates were higher in the silver ISH (SISH) subgroup than in the fluorescence ISH (FISH) and chromogenic ISH (CISH) subgroups. In diagnostic test accuracy review, the pooled sensitivity and specificity were 0.86 (95% CI 0.84-0.87) and 0.91 (95% CI 0.90-0.91). The AUC on SROC curve was 0.958. However, there was no significant difference in the values of AUC between the ISH methods.

CONCLUSIONS

Our results showed that HER2 IHC was well concordant with ISH in HER2 IHC score 0/1+ or 3+. Although this meta-analysis showed higher diagnostic accuracy of HER2 IHC, more detailed criteria for HER2 IHC score 2+ cases will be required to predict HER2 status.