HER2 in Gastric Cancer: An Immunohistochemical Study on Tissue Microarrays and the Coressponding Whole-Tissue Sections with a Supplemental Fish Study

A comparative study of RTK gene status between primary tumors, lymph-node metastases, and Krukenberg tumors

Krukenberg tumor (KT) refers to a rare ovarian tumor that has metastasized from a primary site. Patients with KTs have a poorer prognosis and worse survival. Thus far, little is known about the frequency of receptor tyrosine kinase (RTK) gene amplification and the concordance of gene amplification between primary tumors, lymph-node metastases, and KTs. Herein, 50 paired samples, including primary cancers, metastatic lymph nodes, and KTs were collected, and RTK gene amplification was tested by fluorescence in situ hybridization (FISH). There were four cases positive for human epidermal growth factor receptor type 2 (HER2) amplification, all of which showed conversion of HER2 status between different lesions. Of the two cases with c-mesenchymal-epithelial transition (c-MET) amplification, the primary tumors and lymph nodes were negative while the right involved ovaries were positive. Inconsistent fibroblast growth factor receptor 2 (FGFR2) status in different lesions was observed in three of the six FGFR2-amplified cases. Co-amplification of RTK genes was identified in only one patient for primary cancer and two for KTs. Collectively, there were 46, 48, 50, and 44 cases negative for HER2, c-MET, EGFR, and FGFR2 amplification in all lesions, respectively. There was no significant difference in overall survival between KTs of gastric origin and colorectal origin. However, of all synchronous cancers, KTs of colorectal origin had a better prognosis than those of gastric origin. In conclusion, the positive rate of RTK gene amplification in KTs was low. Intratumoral heterogeneity was frequent in KTs with RTK gene amplification. A mutually exclusive pattern of RTK gene amplification was dominant in primary cancers, lymph-node metastases, and KTs. There was no survival difference between KTs of gastric origin and colorectal origin. However, of all synchronous cancers, KTs of colorectal origin had a better prognosis than those of gastric origin.

Clinicopathological features and Borrmann classification associated with HER2-positive in primary gastric cancer

PURPOSE

Human epidermal growth factor receptor 2 (HER2) assesment is important for patients with advanced gastric cancer (GC) to determine trastuzumab therapy is being considered. A study was performed to evaluate the rate of HER2 positivity in patients with primary gastric cancer and to assess the relationship between HER2-positive and Borrmann classification.

PATIENTS AND METHODS

Four hundred and sixty-one patients with gastric or gastroesophageal junction cancer were confirmed as having adenocarcinoma between 2005 and 2016. HER2 status was assessed using immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH). Tissues were considered to be HER2-positive when assessment revealed either an IHC score of 3+ or IHC score 2+ accompanied by a positive FISH result.

RESULTS

The HER2-positive rate was significantly higher in men than in women (19% vs 9%; p=0.006). In our study, HER2-positive gastric tumors with differentiated histology were significantly higher. The proportion of HER2-positive gastric tumors of Borrmann classification III or IV was significantly higher than tumors classified as I or II.

CONCLUSIONS

HER2-positive gastric cancer tends to be associated with male gender, differentiated histology, and Borrmann tumor classification of III or IV.

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.

The clinicopathological parameters and prognostic significance of HER2 expression in gastric cancer patients: a meta-analysis of literature

Background

Human epidermal growth factor receptor-2 (HER2) is regarded as an important and promising target in the treatment of HER2-positive breast cancers. However, the correlation of clinicopathological characteristics and prognostic significance of HER2 overexpression in gastric cancer patients remains unclear. Our aim was to clarify this issue.

Methods

Embase, PubMed, and the Cochrane Library were searched for relevant articles published up to May 2016. Outcomes of interest contained sex, age, tumor size, tumor site, tumor node metastasis (TNM) stage, distant metastasis, lymph node metastasis, Lauren’s classification, differentiation grade, lymphovascular invasion, neural invasion, and multivariate analysis data for overall survival.

Results

A total of 41 studies of 17,494 gastric cancer patients were identified with HER2 test. HER2 positive rate was 19.07% (95% CI = 9.16, 28.98). There existed statistical significance between HER2 overexpression and patients’ prognosis (RR = 1.47, 95% CI = 1.09, 1.98). Male patients (OR = 1.48, 95% CI = 1.34, 1.65), proximal tumors (OR = 1.25, 95% CI = 1.07, 1.47), intestinal-type tumors (OR = 3.37, 95% CI = 2.54, 4.47), advanced stage cancers (OR = 1.35, 95% CI = 1.10, 1.66), lymph node metastasis (OR = 1.26, 95% CI = 1.14, 1.41), well-differentiated cancers (OR = 1.79, 95% CI = 1.15, 2.76), and distant metastasis (OR = 1.91, 95% CI = 1.08, 3.38) were correlated with higher HER2 expression rates. However, no statistical differences existed in age, tumor size, lymphovascular invasion, or neural invasion. Subgroup analysis revealed that HER2 expression rates reported in articles from Asian (19.52%) countries were quantitatively higher than those from European (16.91%) areas. Results were consistent with those reports that define HER2 status according to trastuzumab for gastric cancer (ToGA) criteria.

Conclusion

This study showed that HER2 overexpression was associated with poor prognosis in gastric cancer patients. HER2 positive rates may be associated with sex, tumor site, TNM staging system, distant metastasis, lymph node metastasis, Lauren’s classification, and differentiation grade in gastric cancer patients. The HER2 expression rate in Asians may be higher than that in Europeans. This study offers a convenient way for doctors to select patients for relevant HER2 detection and following treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12957-017-1132-5) contains supplementary material, which is available to authorized users.

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.

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.

[Comparative study of the determination of the HER2 status in gastric cancer in the biopsy and intraoperative specimens]

OBJECTIVE

To determine the HER2 status of gastric adenocarcinomas, by using biopsy and intraoperative specimens.

SUBJECTS AND METHODS

Immunohistochemistry and in situ hybridization were used to examine the HER2 status of 346 gastric cancer biopsy and intraoperative specimens.

RESULTS

The study conducted on a large Russian sample of 346 patients showed a positive HER2 status in 10.7% of the examined specimens. Intestinal-type adenocarcinomas exhibited a positive HER2 status in 21.4% of the cases. Comparative analysis of the HER2 status in the biopsy and intraoperative specimens indicated that there were differences in the determination of the tumor HER2 status in less than 1% of the examined specimens. The remaining found differences (14.7%) failed to change the tumor HER2 status and to affect the choice of a treatment regimen.

CONCLUSION

The performed investigation has demonstrated that the tumor HER2 status determined in the biopsy specimen significantly reflects the molecular biological properties of gastric cancer and may be clinically used to determine indications for the use of targeted drugs.