HER-2/neu amplification is an independent prognostic factor in gastric cancer

HER2 screening data from ToGA: targeting HER2 in gastric and gastroesophageal junction cancer

BACKGROUND

In the Trastuzumab for GAstric cancer (ToGA) study, trastuzumab plus chemotherapy improved median overall survival by 2.7 months in patients with human epidermal growth factor receptor 2 (HER2)-positive [immunohistochemistry (IHC) 3+/fluorescence in situ hybridization-positive] gastric/gastroesophageal junction cancer compared with chemotherapy alone (hazard ratio 0.74). Post hoc exploratory analyses in patients expressing higher HER2 levels (IHC 2+/fluorescence in situ hybridization-positive or IHC 3+) demonstrated a 4.2-month improvement in median overall survival with trastuzumab (hazard ratio 0.65). The ToGA study provides the largest screening dataset available on HER2 overexpression/amplification in this indication. We further analyzed correlation(s) of HER2 overexpression/amplification with clinical and epidemiological factors.

METHODS

HER2-positivity was analyzed by histological subtype, tumor location, geographic region, and specimen type. Exploratory efficacy analyses were performed.

RESULTS

The HER2-positivity rate was 22.1 % across analyzed tumor samples. Rates were similar between European and Asian patients (23.6 % vs. 23.9 %), but higher in intestinal- vs. diffuse-type (31.8 % vs. 6.1 %), and gastroesophageal junction cancer versus gastric tumors (32.2 % vs. 21.4 %). Across all IHC scores, variability in HER2 staining (≤30 % stained cells) was observed in almost 50 % of cases, with increasing rates in lower IHC categories, and did not affect treatment outcome. The polysomy rate was 4 %.

CONCLUSIONS

HER2 expression varies by tumor location and type. All patients with advanced gastric or gastroesophageal junction cancer should be tested for HER2 status, preferably using IHC initially. Due to the unique characteristics of gastric cancer, specific testing/scoring guidelines should be adhered to.

Study of C-MYC amplification and expression in Iranian gastric cancer samples using CISH and IHC methods

Background:

Gastric cancer is the fourth most frequent malignancy and the second cause of cancer-related mortality worldwide. It has been suggested that in gastric carcinogenesis, the C-MYC gene has an important function. The objective of this study is to establish the preference of Chromogenic in situ hybridization (CISH) and Immunohistochemistry (IHC) in the diagnosis and prognosis of gastric cancer.

Materials and Methods:

Samples comprised of 50 randomly selected patients of whom 40 were male and 10 female. To evaluate the MYC copy number and its protein expression, CISH and IHC analyses were performed for 50 gastric adenocarcinomas, in Iran.

Results:

The location of the tumor in 64% of the patients was the fundus, and in 72% of patients, the tumors were of a diffuse type; 22 samples showed no amplification, and 28 samples were with amplification. MYC immunoreactivity was observed in 13 samples. Twelve samples showed both MYC amplification and MYC immunoreactivity. In addition, among the 28 CISH+ samples, 12 samples had positive signals for IHC and 16 samples had negative signals for IHC. A majority of the IHC-negative patients had no amplification, but only one patient with IHC positive had no amplification.

Conclusion:

Our conclusion was that for the management and treatment of gastric cancer, and for special attention of clinicians, for prognosis and tumor progression, the CISH was a better and more feasible test than IHC, in regard to the sensitivity and specificity.

HER2 directed therapy for gastric/esophageal cancers

OPINION STATEMENT

The majority of patients with esophagogastric cancer present with advanced disease, which is incurable. Systemic chemotherapy can lead to a decrease in cancer-related symptoms and prolongs survival. However, even with treatment, the prognosis remains poor; most patients with advanced disease have a median overall survival less than one year. Molecularly targeted therapies, such as those targeting human epidermal growth factor receptor 2 (HER2), are anticipated to improve the current status of systemic treatment beyond conventional cytotoxic therapy. Trastuzumab in combination with chemotherapy in patients is the first molecular agent in metastatic HER2 positive gastric and gastroesophageal adenocarcinomas to result in improvements in response rates, time to progression and survival. Trastuzumab is now being investigated in the neoadjuvant and adjuvant setting. Unfortunately, as with breast cancer, many esophagogastric patients will develop resistance to trastuzumab. Several promising therapies are currently under investigation as monotherapy and in combination with chemotherapy in the first and second line setting.

In vivo molecular imaging of HER2 expression in a rat model of Barrett's esophagus adenocarcinoma

Human epidermal growth factor receptor 2 (HER2) is involved in the malignant progression of several human cancers, including esophageal adenocarcinoma (EAC). The purpose of this study was to evaluate HER2 overexpression and to explore the feasibility of confocal laser endomicroscopy for in vivo molecular imaging of HER2 status in an animal model of Barrett's-related EAC. Rats underwent esophagojejunostomy with gastric preservation. At 30 weeks post-surgery, the esophagus of 46 rats was studied; endoscopic and histological findings were correlated with HER2 immunofluorescence on excised biopsies and gross specimens. At this age, 23/46 rats developed Barrett's esophagus (BE), and 6/46 had cancer (four EAC and two squamous cell carcinomas). A significant overexpression of HER2 was observed in esophageal adenocarcinoma compared with normal squamous esophagus (9.4-fold) and BE (6.0-fold). AKT and its phosphorylated form were also overexpressed in cancer areas. Molecular imaging was performed at 80 weeks post-surgery in four rats after tail injection of fluorescent-labeled anti-HER2 antibody. At this age, 3/4 rats developed advance adenocarcinoma and showed in vivo overexpression of HER2 by molecular confocal laser endomicroscopy with heterogeneous distribution within cancer; no HER2 signal was observed in normal or Barrett's tissues. Therefore, HER2 overexpression is a typical feature of the surgical induced model of EAC that can be easily quantified in vivo using an innovative mini-invasive approach including confocal endomicroscopy; this approach may avoid limits of histological evaluation of HER2 status on 'blinded' biopsies.

Correlations of Human Epithelial Growth Factor Receptor 2 Overexpression with MUC2, MUC5AC, MUC6, p53, and Clinicopathological Characteristics in Gastric Cancer Patients with Curative Resection

Background. The purpose of this study was to evaluate the relationships between HER2 overexpression in the tumor and MUC2, MUC5AC, MUC6, and p53 status and clinicopathological characteristics of gastric cancer patients. Methods. This retrospective study included 282 consecutive patients with gastric cancer who underwent surgery at the Kosin University Gospel Hospital between April 2011 and December 2012. All tumor samples were examined for HER2 expression by immunohistochemistry (IHC) and MUC2, MUC5AC, MUC6, and p53 expression by staining. A retrospective review of the medical records was conducted to determine the correlation between the presence of HER2 overexpression and clinicopathological factors. Results. The HER2-positive rate was 18.1%. Although no association was found between HER2 expression and MUC5AC, the expression of MUC2, MUC6, and p53 was significantly correlated with HER2 positivity, respectively (P = 0.004, 0.037, 0.002). Multivariate analysis revealed that HER2 overexpression and nodal status were independent prognostic factors. Conclusions. HER2 overexpression in gastric carcinoma is an independent poor prognostic factor.

HER2 in solid tumors: more than 10 years under the microscope; where are we now?

HER2 is a well-recognized mediator of the cancerogenic process. It is dysregulated in a wide range of solid tumors, mainly via protein overexpression and/or gene amplification, thus making HER2 an attractive target for tailored treatment. The anti-HER2 therapy trastuzumab was approved for the treatment of HER2-positive metastatic breast cancer patients more than 10 years ago. Since then, trastuzumab and other HER2-inhibitors have been entered into clinical practice for the treatment of breast cancer and, more recently, have been approved to treat HER2-positive metastatic gastric cancers. Currently, HER2-targeted therapies are under evaluation in other tumor types. Due to the relevance of proper patient selection, the accurate assessment of HER2 status is fundamental. This review will discuss the established knowledge and novel insights into the HER2 story, mainly focusing on breast, gastric and colorectal cancers, as well as providing a brief overview of salivary gland, bladder, ovarian and lung tumors.

Protein expression of HER2, 3, 4 in gastric cancer: correlation with clinical features and survival

BACKGROUND AND AIMS

Despite significant improvements in targeted therapies for patients with advanced gastric cancer (GC), the prognosis of those patients remains poor. This study explores the expression and clinicopathological significance of human epidermal growth factor receptor 2, 3 and 4 (HER2, HER3, HER4) in GC, in order to find more prognostic biomarkers of GC and putative targets of therapy.

METHODS

Immunohistochemistry was performed for HER2, HER3 and HER4 in 498 patients with GC using tissue microarray. Correlations between the receptor expression and clinicopathological features, as well as prognosis of the patients were statistically analysed.

RESULTS

The high expression rates of HER2, HER3 and HER4 proteins in the patients were 8.6% (43/498), 20.7% (103/498) and 13.3% (66/498), respectively. High expression of HER2 and HER3 was correlated with proximal GC of the cardia (p<0.05). High expression of HER3 was associated with the tumour depth, tumour node metastasis (TNM) stage and lymph node metastasis (p<0.05). High expression of HER4 was associated with TNM stage (p<0.05) only. According to a regression model, high expression of HER3 was significantly associated with patients' poor survival (p=0.004). High expression rates of HER2, HER3 and HER4 were correlated with each other, but they were all associated merely with histologically intestinal-type adenocarcinoma of GC (p<0.05).

CONCLUSIONS

HER3 is correlated with the malignant biological behaviour of GC. Expression of HER3 is a significant predictor of poor survival in GC. Therefore, the development of HER3-targeted agents may provide new possibilities in the treatment of GC.

HER 2 Expression in Gastric and Gastro-esophageal Junction (GEJ) Adenocarcinomas

INTRODUCTION

Gastric cancer is one of the leading causes of cancer mortality in the world/India with majority being diagnosed at an advanced stage. Various chemotherapeutic regimens have modestly improved overall survival leading to quest for novel therapeutic agents. Overexpression of HER2 in many gastric cancers has lead to the advent of targeted therapy with anti HER2 antibody like Trastusumab which has improved the overall survival.

MATERIALS AND METHODS

Sixty cases of gastric adenocarcinomas (44 biopsies and 16 gastrectomies) over the past five years ( June 2009 to June 2014),were included in the study. Diagnosis was confirmed by review of slides and IHC with anti HER2 antibodies was performed using Dako Real Envision Detection system and scoring was done by Hoffmann et al., scoring system.

RESULTS

Of the 60 cases, majority were males (60%),with a mean age of 65.65 yrs. Tumours in antrum (76.7%) formed the major bulk. HER2 expression was observed in 26.7% of Tumours, predominantly in males (p=0.006) and intestinal type (p= 0.054). HER2 expression correlated with Tumour grade (moderately differentiated and well differentiated, p= 0.042). Tumours of gastro-esophageal junction (GEJ) showed HER2 expression in 45.5% as opposed to 22.4% in gastric location. Poorly differentiated and diffuse type of adenocarcinomas did not express HER2. Two of three Tumours from patients in the age group 31-40 y expressed HER2.

CONCLUSION

Male gender, intestinal-type and moderately differentiated gastric cancers may be the ones that can be targeted for therapy using Herceptin. Though trastusumab is approved for advanced gastric and GEJ cancers, it's role in adjuvant / neo-adjuvant setting in early stages needs to be evaluated with newer agents like Pertuzumab, Bevacizumab, especially in young patients.

Prognostic implications of EGFR and HER-2 alteration assessed by immunohistochemistry and silver in situ hybridization in gastric cancer patients following curative resection

BACKGROUND

The aim of this study was to use immunohistochemistry (IHC) and silver in situ hybridization (SISH) to evaluate alterations in EGFR and HER2 in gastric cancer in order to determine the relationship with prognosis in gastric cancer patients following curative resection.

PATIENTS AND METHODS

In this study, we analyzed EGFR and HER-2 status by IHC and SISH in 254 stage I-III gastric cancer patients who underwent curative surgery.

RESULTS

Thirteen cases (2.48 %) showed EGFR alteration by IHC or SISH. EGFR alteration was associated with older age (P = 0.021), intestinal type (P = 0.040) and higher stage disease (P < 0.001). The patients with operable state gastric cancer who had EGFR alteration had an unfavorable prognosis, and multivariate analysis confirmed that EGFR alteration was an independent unfavorable prognostic factor. Twenty-seven cases (10.6 %) showed HER-2 alteration by IHC or SISH. HER-2 alteration was associated with older age (P = 0.006), well or moderately differentiated histology (P < 0.001) and intestinal type (P = 0.002).

CONCLUSION

HER-2 alteration is not an independent prognostic factor for curatively resectable gastric cancer. We observed EGFR alteration in a subset of cases with operable state gastric cancer and determined that it was associated with an unfavorable prognosis.

From molecular classification to targeted therapeutics: the changing face of systemic therapy in metastatic gastroesophageal cancer

Histological classification of adenocarcinoma or squamous cell carcinoma for esophageal cancer or using the Lauren classification for intestinal and diffuse type gastric cancer has limited clinical utility in the management of advanced disease. Germline mutations in E-cadherin (CDH1) or mismatch repair genes (Lynch syndrome) were identified many years ago but given their rarity, the identification of these molecular alterations does not substantially impact treatment in the advanced setting. Recent molecular profiling studies of upper GI tumors have added to our knowledge of the underlying biology but have not led to an alternative classification system which can guide clinician's therapeutic decisions. Recently the Cancer Genome Atlas Research Network has proposed four subtypes of gastric cancer dividing tumors into those positive for Epstein-Barr virus, microsatellite unstable tumors, genomically stable tumors, and tumors with chromosomal instability. Unfortunately to date, many phase III clinical trials involving molecularly targeted agents have failed to meet their survival endpoints due to their use in unselected populations. Future clinical trials should utilize molecular profiling of individual tumors in order to determine the optimal use of targeted therapies in preselected patients.

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.

Recent advances in the HER2 targeted therapy of gastric cancer

Recent advances in molecular targeted therapies, including targeting human epidermal growth factor receptor 2 (HER2), had a major forward step in the therapy for gastric cancer patients. Application of HER2-targeted therapies, in particular trastuzumab in combination with chemotherapy in metastatic HER2-positive gastric cancers, resulted in improvements in response rates, time to progression and overall survival. Nevertheless, as with breast cancer, many patients with gastric cancer develop resistance to trastuzumab. Several promising therapies are currently being developed in combination with chemotherapy to increase the efficacy and overcome the cancer-resistance. Here we review the current overview of clinical application of agents targeting HER2 in gastric cancer. We also discuss the ongoing trials supporting the use of HER2-targeted agents combined with cytotoxic agents or other monoclonal antibodies.

HER2 assessment by silver in situ hybridization: where are we now?

HER2 testing in breast and gastric cancer is critical not only as a prognostic tool but also as a predictive marker for response to the humanized monoclonal antibody trastuzumab. Currently, HER2 status is assessed on histological and cytological specimens by conventional validated methods such as immunohistochemistry and FISH, while bright-field in situ hybridization techniques, such as silver in situ hybridization and chromogenic in situ hybridization, may offer performance benefits over FISH. The major points are first, technical issues, advantages and disadvantages relevant to each methods, and their clinical implications and second, the well-known genetic heterogeneity of HER2, and the occurrence of polysomy of chromosome 17. This review aims to summarize the growing body of literature on the accuracy of bright-field in situ techniques, notably silver in situ hybridization, in assessing HER2 status, and to discuss the role of such methods in pathology practice.

The advent of precision therapy in gastrointestinal malignancies: Targeting the human epidermal growth factor receptor family in colorectal and esophagogastric cancer

Until recently, systemic therapy for gastrointestinal malignancies was restricted to relatively noncancer-specific cytotoxic chemotherapy. Over the last 15 years targeted therapies have become available, most notably bevacizumab in the case of advanced colorectal cancer. Unfortunately, there are no predictive biomarkers to guide the use of this agent. In this review article, we describe the advent of “Precision Medicine” (in part, the use of patient-specific molecular markers to inform treatment) in gastrointestinal cancers: The use of monoclonal antibodies targeting epidermal growth factor receptor in advanced colorectal cancer, and human epidermal growth factor receptor 2-neu in advanced esophagogastric cancer. In both instances, biomarkers help in selecting appropriate patients for such treatment.

Immunohistochemical molecular phenotypes of gastric cancer based on SOX2 and CDX2 predict patient outcome

Background

Gastric cancer remains a serious health concern worldwide. Patients would greatly benefit from the discovery of new biomarkers that predict outcome more accurately and allow better treatment and follow-up decisions. Here, we used a retrospective, observational study to assess the expression and prognostic value of the transcription factors SOX2 and CDX2 in gastric cancer.

Methods

SOX2, CDX2, MUC5AC and MUC2 expression were assessed in 201 gastric tumors by immunohistochemistry. SOX2 and CDX2 expression were crossed with clinicopathological and follow-up data to determine their impact on tumor behavior and outcome. Moreover, SOX2 locus copy number status was assessed by FISH (N = 21) and Copy Number Variation Assay (N = 62).

Results

SOX2 was expressed in 52% of the gastric tumors and was significantly associated with male gender, T stage and N stage. Moreover, SOX2 expression predicted poorer patient survival, and the combination with CDX2 defined two molecular phenotypes, SOX2⁺CDX2^- versus SOX2^-CDX2⁺, that predict the worst and the best long-term patients’ outcome. These profiles combined with clinicopathological parameters stratify the prognosis of patients with intestinal and expanding tumors and in those without signs of venous invasion. Finally, SOX2 locus copy number gains were found in 93% of the samples reaching the amplification threshold in 14% and significantly associating with protein expression.

Conclusions

We showed, for the first time, that SOX2 combined with CDX2 expression profile in gastric cancer segregate patients into different prognostic groups, complementing the clinicopathological information. We further demonstrate a molecular mechanism for SOX2 expression in a subset of gastric cancer cases.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-753) contains supplementary material, which is available to authorized users.

Detection of Her-2/neu expression in gastric cancer: Quantitative PCR versus immunohistochemistry

The aim of this study was to compare quantitative polymerase chain reaction (qPCR) with immunohistochemistry (IHC) for the detection of Her-2 in gastric cancer, and to investigate the correlation between the expression levels of human epidermal growth factor receptor 2 (Her-2) and clinical features. Clinical data from 426 cases of gastric cancer were collected. Her-2 expression levels in cancerous tissue were detected using IHC, and the Her-2/neu gene expression levels were determined by qPCR. The correlation between the expression level of Her-2 and clinical features was investigated. The positive expression rate of Her-2 in cancerous tissue detected using qPCR and IHC was 11.17% (46/412) and 13.38% (57/426), respectively. The positive expression of the Her-2 protein/gene was significantly correlated with the depth of invasion and lymphatic metastasis, as well as the TNM stage (P<0.05). No significant correlation was identified between positive expression of the Her-2 protein/gene and tumor location, age, gender, differentiation degree and Lauren classification (P>0.05). The diagnostic consistency was good between the two methods (κ=0.828). The results indicate that the expression of Her-2/neu is closely associated with the development of gastric cancer. qPCR is a convenient, objective and efficient method, which may be used as an alternative to IHC or fluorescence in situ hybridization for the detection of Her-2/neu gene.

Human epidermal growth factor receptor 2 testing in gastric cancer: recommendations of an Asia-Pacific task force

Human epidermal growth factor receptor 2 (HER2) testing in gastric and gastroesophageal junction cancer is an evolving area in clinical practice that has particular relevance to Asia-Pacific countries, which face a high incidence of these diseases. A growing body of evidence demonstrates that HER2-targeted therapy improves survival for patients with HER2-positive advanced disease, and drives the need for high-quality testing procedures to identify patients who will respond to treatment. However, various factors challenge day-to-day testing of gastric specimens in these countries, to a degree greater than that observed for breast specimens. Recommendations for HER2 testing of gastric cancer specimens were published as a result of the Trastuzumab for Gastric Cancer (ToGA) trial. The guidelines proposed in this manuscript build on these recommendations and emphasize local testing environments, particularly in Asia-Pacific countries. A multidisciplinary task force comprising experts from Asia-Pacific who actively work and provide education in the area was convened to assess the applicability of existing recommendations in the Asia-Pacific region. The resulting recommendations reported here highlight and clarify aspects of testing that are of particular relevance to the region, and notably emphasize multidisciplinary collaborations to optimize HER2 testing quality.

The impact of Helicobacter pylori on EGF, EGF receptor, and the c-erb-B2 expression

PURPOSE

Increased expression of epidermal growth factor (EGF), its receptor (EGFR), and c-erb-B2 protein, which is homological with the EGF receptor, in gastric mucosa, may play a role in gastric carcinogenesis. We assessed if the infection and eradication of Helicobacter pylori (H. pylori) affects the gastric expression of growth factors and serum gastrin concentrations.

PATIENTS/METHODS

We examined immunohistochemically gastric EGF and both receptors' expression in: gastric cancer (GC; n=29), chronic gastritis with H. pylori infection (GHp+; n=40) before and after eradication and in patients without H. pylori infection (GHp-; n=42).

RESULTS

Before the eradication therapy, gastric mucosal EGF and both receptor's expressions in GHp+ patients were increased compared to GHp- (p<0.05), but were similar to GC. After eradication, EGF and the receptor's expression significantly decreased in the gastric body. Both EGFR and c-erb-B2 expression in the antrum were still higher than in GHp- (p<0.05), and remained comparable to GC.

CONCLUSIONS

In patients with H. pylori infection the gastric mucosal EGF, EGFR, and c-erb-B2 expressions are similar to those observed in gastric cancer. The persistence of the antral expression of receptors after eradication, at a level comparable to the gastric cancer group, suggests their eventual role in the progression of changes initiated by H. pylori toward carcinogenesis.

Lapatinib plus paclitaxel versus paclitaxel alone in the second-line treatment of HER2-amplified advanced gastric cancer in Asian populations: TyTAN--a randomized, phase III study

PURPOSE

In Asian countries, paclitaxel once per week is used as second-line treatment in advanced gastric cancer, including human epidermal growth factor receptor 2 (HER2) -positive tumors. The role of anti-HER2 agents, including lapatinib, in this setting and population is unclear.

PATIENTS AND METHODS

TyTAN was a two-part, parallel-group, phase III study in Asian patients. An open-label, dose-optimization phase (n = 12) was followed by a randomized phase (n = 261), in which patients who were HER2 positive by fluorescence in situ hybridization (FISH) received lapatinib 1,500 mg once per day plus once-per-week paclitaxel 80 mg/m(2) or paclitaxel alone. The primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS), time to progression (TTP), overall response rate (ORR), time to response, response duration, and safety. Analyses were based on immunohistochemistry (IHC) and gastrectomy status, prior trastuzumab therapy, and regional subpopulations.

RESULTS

Median OS was 11.0 months with lapatinib plus paclitaxel versus 8.9 months with paclitaxel alone (P = .1044), with no significant difference in median PFS (5.4 v 4.4 months) or TTP (5.5 v 4.4 months). ORR was higher with lapatinib plus paclitaxel versus paclitaxel alone (odds ratio, 3.85; P < .001). Better efficacy with lapatinib plus paclitaxel was demonstrated in IHC3+ compared with IHC0/1+ and 2+ patients and in Chinese compared with Japanese patients. A similar proportion of patients experienced adverse events with each treatment (lapatinib plus paclitaxel, 100% v paclitaxel alone, 98%).

CONCLUSION

Lapatinib plus paclitaxel demonstrated activity in the second-line treatment of patients with HER2 FISH-positive IHC3+ advanced gastric cancer but did not significantly improve OS in the intent-to-treat population.

Comparison of HER2 status between surgically resected specimens and matched biopsy specimens of gastric intestinal-type adenocarcinoma

HER2 protein overexpression and gene amplification are important biomarkers for identifying gastric cancer patients who may respond to HER2-targeted therapy using trastuzumab. The aim of this study was to evaluate the concordance between HER2 protein expression and gene amplification in both surgically resected tumors and matched biopsy specimens of gastric cancer. Formalin-fixed, paraffin-embedded sections of 207 surgically resected tumors and 158 biopsy specimens from 207 cases of invasive intestinal-type gastric cancer were analyzed. Protein expression was assessed using immunohistochemistry and graded by the modified scoring criteria for gastric cancer. Gene amplification was evaluated by fluorescence in situ hybridization (FISH). HER2 overexpression was observed in 17 % of both surgically resected tumors (35/207) and biopsy specimens (26/158). HER2 gene amplification was detected in 31 % (61/200) of surgically resected tumors and 32 % (47/147) of biopsy specimens. Except for immunohistochemistry (IHC) equivocal (2+) cases, the concordance rates between IHC and FISH was 90.9 % in surgically resected tumors and 90.2 % in biopsy specimens. In IHC 2+ cases, the rate of HER2 gene amplification was 56 and 38 % in surgically resected tumors and biopsy specimens, respectively. IHC-FISH discordance was mainly due to intratumoral heterogeneity and low-level gene amplification. The concordance rate of IHC results between surgically resected specimens and the corresponding biopsy specimen was 57.0 % (κ = 0.224), and in discordant cases, HER2 positivity in biopsies and HER2 negativity in surgically resected tumors were most common. The concordance rate of FISH results between surgically resected tumors and biopsy specimens was 72.7 % (κ = 0.313). Polysomy 17 was detected in 5.5 and 7.5 % of surgically resected tumors and biopsy specimens and significantly correlated with IHC score, but polysomy 17 could explain one IHC score 3+ and FISH-negative tumor only. Although high concordance rates between HER2-protein expression and gene amplification were observed in both surgically resected tumors and biopsy specimens, the agreement levels were evaluated to be fair. Polysomy 17 was infrequent and seemed to have limited impact on gastric HER2 testing. Further investigations are required for an appropriate biopsy method to reduce false results of HER2 testing and to clarify the clinical significance of intratumoral heterogeneity in HER2 status.

A critical review of HER2-positive gastric cancer evaluation and treatment: from trastuzumab, and beyond

Identification of the importance of human epidermal growth factor receptor-2 (HER2) status, biomarker testing and the development of anti-HER2 treatments have changed the prognosis of breast and gastric cancers. The addition of trastuzumab to chemotherapy has improved outcomes for patients with HER2-positive metastatic adenocarcinoma of the stomach and gastroesophageal junction, but some relevant issues remain to be elucidated or will emerge with new drugs. This article reviews the current state of HER2 in gastric cancer focusing on diagnostic and anti-HER2 targeted treatment issues and the role of trastuzumab in localized disease, and its combination or integration with new therapies.

Frequency of HER2/neu overexpression in adenocarcinoma of the gastrointestinal system

AIM: To determine the frequency of HER2/neu protein overexpression in gastric (group A), small intestine (group B), and colorectal (group C) adenocarcinoma.

METHODS: A descriptive, cross-sectional study was performed on 50 cases of gastrointestinal adenocarcinoma (stomach, small intestine, and colorectal); 11 from group A, 8 from group B, and 31 from group C. The samples were grossed and processed in the pathology department, and sections were stained with HE (hematoxylin and eosin stain) for histopathological confirmation of malignancy (well-differentiated, moderately-differentiated, and poorly-differentiated). The confirmed samples were processed for immunomarker study of HER2/neu.

RESULTS: HER2/neu protein overexpression was found in 33 (66%) patients overall (P = 0.000). Out of 33 HER2/neu positive subjects, 23 (69.6%) were from group C, while the remaining 10 (30%) were from group A. None of the patients from group B had positive HER2/neu protein overexpression. No protein overexpression or membrane staining in < 10% tumor cells was observed in 17 (34%) patients, which were labeled as score “0” and considered negative for HER2/neu protein overexpression. Faint/weak staining (in ≥ 10% of tumors cells) were observed in 8 (16%) patients and given the “1+” score. Similarly 13 (26%) patients reported moderate staining (in ≥ 10% tumor cells) and were thus labeled as “2+”, and strong staining (in ≥ 10% tumors cells), labeled as “3+”, was observed in 12 (24%) patients. Out of 50 patients, 26 (52%) were suffering from grade-II malignancy, 16 (32%) from grade-I, and 8 (16%) from grade-III. There was highly significant association between tumor grades and HER2/neu protein overexpression (P = 0.0000).

CONCLUSION: HER2/neu protein is credibly overexpressed in colon and gastric adenocarcinomas in immunohistochemistry. There is significant association between grade of tumor and HER2/neu protein overexpression.

Profiling the prognosis of gastric cancer patients: is it worth correlating the survival with the clinical/pathological and molecular features of gastric cancers?

BACKGROUND

The prognosis of gastric cancer patients still remains poor. The aim of this study was investigating the prognostic value of several clinical/pathological/molecular features in a consecutive series of gastric cancers.

METHODS

150 R0 gastrectomies plus 77 gastric cancer patients evaluated for the HER2 overexpression were selected. Survival was calculated and patients stratified according to the stage, the T-stage, the LNRs, the LNH, and the HER2 scoring system. ROC curves were calculated in order to compare the performance of the LRN and LNH systems.

RESULTS

Prognosis correlated with the stage and with the T-stage. We documented a statistical correlation between the LNRs and the survival. Conversely, a LNH > 15 did not correlate with the outcomes. The ROC curves documented a significant performance of the LRN system, whereas a statistical correlation was documented for the LNH exclusively with the endpoint of disease-free survival. We documented a trend of worse prognosis for patients with an HER2 overexpression, even though it was not of statistical value.

CONCLUSION

The LNR and the evaluation of the HER2 overexpression might be useful since they correlate with survival, might identify patients with a higher risk of recurrence, and might select patients for a tailored medical treatment.

Clinicopathological and prognostic significance of HER2 overexpression in gastric cancer: a meta-analysis of the literature

Human epidermal growth factor receptor 2 (HER2) plays an important role in the aggressiveness and progression of gastric cancer. With the publication of trial results, we conducted a meta-analysis to investigate its prognostic significance for patients with gastric cancer. PubMed, Ovid, Web of Science, and Cochrane databases were searched. Statistical analysis was carried out by STATA version 12.0 software. The Newcastle-Ottawa scale was used to assess the quality of evidence. Fifteen studies involving 5,290 patients met the inclusion criteria. The results showed that HER2 overexpression was significantly associated with patients' overall survival (HR = 1.56, 95% confidence interval (CI) 1.05-2.07; Z = 6.03; P = 0.000). The results also suggested that HER2 overexpression was associated with Bormann type (odds ratio (OR) = 1.76, 95% CI 1.19-2.59; Z = 2.85; P = 0.004), tumor differentiation (OR = 3.14, 95% CI 1.91-5.17; Z = 4.49; P = 0.000), Lauren's classification (OR = 6.25, 95% CI 4.29-9.10; Z = 9.54; P = 0.000), lymph node metastasis (OR = 1.43, 95% CI 1.15-1.77; Z = 3.23; P = 0.001), venous invasion (OR = 1.69, 95% CI 1.15-2.48; Z = 2.67; P = 0.008), and lymphovascular invasion (OR = 1.57, 95% CI 1.21-2.04; Z = 3.4; P = 0.001). However, it had no correlation with tumor size, depth of invasion, and tumor stage. This study showed that HER2 overexpression had an unfavorable prognostic role for patients with gastric cancer. HER2-positive expression was associated with Bormann type, Lauren's classification, tumor differentiation, lymph node status, venous invasion, and lymphovascular invasion.

Significance and role of HER2 in targeted therapy of gastric cancer

With the development of tumor molecular biology, the mechanisms responsible for metastasis and the proliferation and growth of tumor cells have become unmasking, which makes cancer treatment enter into a new era. HER2 is overexpressed or mutated in many kinds of tumors and have been associated with many malignant tumors, typically including advanced gastric and gastroesophageal junction cancer. The ToGA study is a milestone in the treatment of gastric cancer, which established the position of trastuzumab in the treatment of HER2-positive gastric cancer. In this review, we discuss the biological characteristics of HER2 and its role in the treatment of gastric cancer, the application prospects of trastuzumab in the treatment of gastric cancer, and the Chinese experts' consensus statement on targeted therapies for advanced gastric cancer. We also summarize the latest advances in basic and clinical research of HER2 positive gastric cancer. All in all, HER2 has nothing to do with the prognosis of gastric cancer. The combination of target-therapies may become a promising weapon for treatment of gastric cancer.

HER2-positive gastric cancer

Human epidermal growth factor receptor 2 (HER2) is involved in the pathogenesis and poor outcomes of several types of cancer, including advanced gastric and gastroesophageal junction cancer. Molecular-targeted drugs, such as trastuzumab, which prolong overall survival and progression-free survival in HER2-positive breast cancer, may also be beneficial in patients with HER2-positive gastric cancer. Several studies have examined this possibility, such as the Trastuzumab for Gastric Cancer trial. In this context, the first part of this review provides an update on our knowledge of HER2 in breast and gastric cancer, including the detection and prognostic relevance of HER2 in gastric cancer. The second part of the review discusses the results of pivotal clinical trials that examined the potential for using trastuzumab to treat this disease. This section also summarizes the trials that have been conducted or that are underway to determine the optimal uses of trastuzumab in gastric cancer, including its use as monotherapy and continuation beyond disease progression. The final section discusses the future prospects of other anti-HER2 drugs, including lapatinib, trastuzumab emtansine, and pertuzumab, for the treatment of HER2-positive gastric cancer. The introduction of trastuzumab led to the establishment of a new disease entity, "HER2-positive gastric cancer," similar to HER2-positive breast cancer. It is expected that more anti-HER2 drugs will be developed and introduced into clinical practice to treat HER2-positive cancers, including gastric cancer.

Evaluation of HER2-based biology in 1,006 cases of gastric cancer in a Japanese population

BACKGROUND

The ToGA trial demonstrated the beneficial effect of trastuzumab in gastric cancer patients with human epidermal growth factor receptor 2 (HER2)-overexpressing tumors. Therefore, evaluation of the relationship between HER2 expression and gastric cancer biology using a validated system has become an even more important task. Herein, we verified the correlation between HER2 overexpression in the tumor and the clinical course of gastric cancer patients.

METHODS

A total of 1,006 consecutive patients with gastric cancer who underwent surgery at the National Cancer Center Hospital East between January 2003 and July 2007 were examined using the tissue microarrays approach. HER2 expression was determined based on an immunohistochemistry score of 3+, or an immunohistochemistry score of 2+ plus HER2 gene amplification as detected by double-color fluorescent in situ hybridization. A retrospective review of the medical records was conducted to determine the correlation between the presence of HER2 overexpression and clinicopathological factors. Then, in 948 patients who had undergone curative resection, HER2 status was compared with the survival.

RESULTS

HER2 overexpression was detected in 118 (11.7 %) patients. HER2 overexpression was correlated with age, gender, grade of differentiation, expanding growth pattern, and nodal status. In the survival analysis, HER2 overexpression was not found to be correlated with either disease-specific survival or recurrence-free survival.

CONCLUSIONS

HER2 overexpression in the tumor was not identified as a significant prognostic factor in patients with operable gastric cancer. The HER2-targeted therapy may be beneficial in a proportion of cases.

Heregulin induces resistance to lapatinib-mediated growth inhibition of HER2-amplified cancer cells

Human epidermal growth factor receptor 2 (HER2) amplification occurs in approximately 20% of gastric and gastroesophageal junction cancers in the United States and European Union. Lapatinib, a dual HER2 and epidermal growth factor receptor tyrosine kinase inhibitor, has demonstrated clinical efficacy in HER2-amplified cancer cells. However, several studies have shown that some cytokines can mediate resistance to lapatinib using their receptor tyrosine kinase (RTK) pathways. One of these, Heregulin1 (HRG1), can confer resistance to lapatinib-mediated growth inhibition in HER2-amplified breast cancer cells, but the underlying mechanisms remain unknown. Here, we investigated whether and how HRG1 causes resistance to lapatinib in gastric and gastroesophageal junction cancers in vitro. HER2-amplified gastric and gastroesophageal junction cancer cell lines were highly sensitive to lapatinib. Exposure to HRG1 together with lapatinib rescued cells from lapatinib-induced cell cycle arrest and apoptosis. Downregulation of HER3 with siRNA in the presence of HRG1 re-sensitized HER2-amplified cancer cells to lapatinib. Immunoblotting analysis indicated that HRG1 re-activated HER3 and AKT in the presence of lapatinib, which persisted for at least 72 h. Activation of HER3 and downstream AKT was mediated by residual activity of HER2. HRG1-mediated resistance could be reduced by PI3K/mTOR inhibitors or by complete inhibition of HER2. Thus, we conclude that HRG1 mediates resistance to lapatinib through HER3 and AKT activation, and that this depends on residual HER2 activity. Lapatinib in combination with anti-PI3K therapies or more potent HER2 inhibitors would improve the efficacy and avoid the emergence of resistant cells.

The siRNA cocktail targeting VEGF and HER2 inhibition on the proliferation and induced apoptosis of gastric cancer cell

The aim of this study was to investigate the inhibitory effect of a siRNA cocktail targeting Vascular endothelial growth factor (VEGF) and Human epidermal growth factor receptor 2 (HER2) on cell proliferation, induced apoptosis and the expression of VEGF and HER2 in human gastric carcinoma cell. The silencing rate of pre-designed siRNAs that targeted VEGF and HER2 was detected by Real-time Quantitative PCR (RT-QPCR) analysis. Furthermore, the best silencing siRNA that targeted VEGF and HER2 was prepared as a cocktail to co-knockdown VEGF and HER2 expression at both mRNA and protein levels which were detected by RT-QPCR and Western blot analysis. Cell proliferation inhibition rates were determined by CCK8 assay. The effect of siRNA cocktail on cell apoptosis was determined by flow cytometry. The migration inhibition of siRNA cocktail was analyzed by wound-healing assay. The ability of VEGF to induce endothelial cells to proliferate was examined in HUVECs by the method of tube formation assay. The pre-designed siRNAs could inhibit VEGF and HER2 mRNA level. siRNA cocktail, and co-downregulation of VEGF and HER2 result in significant inhibition of gastric cancer growth and migration in vitro. The inhibition of VEGF and HER2 expressions can induce apoptosis of SGC-7901 cells.

HER2 in gastric cancer: Comparative analysis of three different antibodies using whole-tissue sections and tissue microarrays

AIM: To compare the performance of three commercially available anti-human epidermalgrowth factor receptor 2 (HER2) antibodies in whole-tissue sections and tissue microarrays (TMAs) of a series of gastric tumors.

METHODS: We present a comparative analysis of three anti-HER2 antibodies (HercepTest, 4B5 and SP3) using TMA and whole-tissue sections prepared from the same paraffin blocks of 199 gastric adenocarcinomas operated upon between January 2004 and December 2008 at a Brazilian cancer hospital. The data on the patients’ age, sex, the anatomical location of the tumor and the Lauren’s histological classification were collected from clinical and pathological records. The immunohistochemical (IHC) results were examined by two pathologists and the cases were classified as positive (3+), equivocal (2+) and negative (0 or 1+), according to the criteria of the IHC scoring system of gastric cancer. TMAs and whole-tissue sections were evaluated separately and independently. All cases yielding discordant IHC results and/or scored as 2+ were subjected to dual-color in situ hybridization in order to determine the final HER2 status. Besides determining the sensitivity and predictive value for HER2-positive status, we measured the accuracy of each antibody by calculating the area under the receiver operating characteristic (ROC) curve. The agreement between the results obtained using the TMAs and those obtained using the whole-tissue sections was assessed by means of Kappa coefficient.

RESULTS: Intratumoral heterogeneity of HER2 expression was observed with all antibodies. HER2-positive expression (3+) in the whole-tissue sections was observed in 23 cases (11.6%) using the 4B5 antibody, in 18 cases (9.1%) using the SP3 antibody and in 10 cases (5.1%) using the HercepTest antibody. In the TMAs, 11 positive cases (5.6%) were identified using SP3 antibody, 9 (4.6%) using the 4B5 antibody and 6 (3%) using the HercepTest antibody. The sensitivity using whole-tissue sections and TMA, respectively, was 95.2% and 42.9% with 4B5, 90.5% and 66.7% with SP3 and 47.6% and 42.9% with HercepTest. The accuracy, calculated from the area under the ROC curve, using whole-tissue sections and TMA, respectively, was 0.91 and 0.79 by 4B5, 0.86 and 0.80 by SP3 and 0.73 and 0.71 by HercepTest. The concordance of the results obtained using whole-tissue sections and TMA was 97.4% (Kappa 0.75) using HercepTest, 85.6% (Kappa 0.56) using SP3 and 84.1% (Kappa 0.38) using 4B5.

CONCLUSION: The use of the 4B5 antibody on whole-tissue sections was the most accurate IHC method for evaluating HER2 expression in gastric adenocarcinoma.

HER2 in resected gastric cancer: Is there prognostic value?

BACKGROUND AND OBJECTIVES

The role of HER2 in patients with early stage/resected gastric cancer is controversial. This study investigates the prevalence and prognostic value of HER2 in patients undergoing curative intent resection for gastric adenocarcinoma.

METHODS

HER2 status was evaluated in 111 patients with gastric adenocarcinoma treated surgically between 1/00 and 6/11 with tissue available for analysis. Immunohistochemistry (IHC) for HER2 was graded by two blinded pathologists. IHC was scored as 0+/1+: negative, 2+: equivocal, and 3+: positive. Fluorescence in situ hybridization (FISH) for HER2 was performed on equivocal (2+) samples, and in cases of pathologist disagreement.

RESULTS

HER2 expression as measured by IHC was negative in 61 (55%), equivocal in 37 (33.3%), and positive in 13 (11.7%) cases. FISH was positive in 8 of 37 samples tested, for a total of 21 HER2-positive cases (18.9%, 95% CI 11.6-26.2%). Patients with HER2-positive tumors were less likely to have signet ring cell features (23.8% vs. 53.9%, P = 0.008). HER2 status was not associated with tumor size, location, perineural or lymphovascular invasion, margin status, nodal metastasis, or stage (P > 0.05). HER2 status was not associated with OS (P = 0.385).

CONCLUSIONS

HER2 amplification/over-expression is present in patients with resected gastric adenocarcinoma, but is not associated with the presence of adverse prognostic factors. Our results suggest HER2 is not prognostic for patients with resected gastric adenocarcinoma.

Assessment of HER2 gene amplification in adenocarcinomas of the stomach or gastroesophageal junction in the INT-0116/SWOG9008 clinical trial

BACKGROUND

Trastuzumab has been approved for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic gastric carcinoma; however, relatively little is known about the role of HER2 in the natural history of this disease.

PATIENTS AND METHODS

Patients enrolled in the INT-0116/SWOG9008 phase III gastric cancer clinical trial with available tissue specimens were retrospectively evaluated for HER2 gene amplification by FISH and overexpression by immunohistochemistry (IHC). The original trial was designed to evaluate the benefit of postoperative chemoradiation compared with surgery alone.

RESULTS

HER2 gene amplification rate by FISH was 10.9% among 258 patients evaluated. HER2 overexpression rate by IHC was 12.2% among 148 patients evaluated, with 90% agreement between FISH and IHC. There was a significant interaction between HER2 amplification and treatment with respect to both disease-free survival (DFS) (P = 0.020) and overall survival (OS) (P = 0.034). Among patients with HER2-non-amplified cancers, treated patients had a median OS of 44 months compared with 24 months in the surgery-only arm (P = 0.003). Among patients with HER2-amplified cancers, there was no significant difference in survival based on treatment arm. HER2 status was not a prognostic marker among patients who received no postoperative chemoradiation.

CONCLUSION

Patients lacking HER2 amplification benefited from treatment as indicated by both DFS and OS.

CLINICAL TRIAL

INT-0116/SWOG9008 phase III.

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

The assessment of human epidermal growth factor receptor 2 (HER2) status in gastric cancer is crucial in selecting patients who may benefit from targeted therapy, yet heterogeneous expression could represent an important drawback for HER2 testing. We aimed to analyze (i) HER2 heterogeneity in primary gastric cancers, pre-neoplastic and metastatic lesions and (ii) HER2 prognostic role. We studied 292 surgically resected primary gastric carcinomas and constructed 21 tissue microarrays including tumor tissue cores, invasive front, paired lymph node metastasis, low- and high-grade dysplasia. Microarrays were immunohistochemically stained with HER2 antibody and digitally scanned. Novel digital analysis algorithms were developed to score HER2 expression. Fluorescence in situ hybridization was performed on equivocal cases. HER2-positive cases were 13% and heterogeneous HER2 expression was observed in 71% of positive samples. Analysis of HER2 status in tumor and tumor invasive front demonstrate concordance in 177 cases (88%). Comparison of HER2 expression in primary cancer and synchronous lymph node metastasis exhibited discordant status in 14% of cases. Dysplastic epithelium surrounding the tumor showed immunohistochemical score 2 or 3 in 19% of high-grade and in 9% of low-grade dysplastic samples. HER2 status was significantly associated with intestinal-type carcinomas (P=0.018) and prognosis since patients with primary HER2-positive tumor showed decreased overall survival (P=0.006). Intratumoral HER2 expression heterogeneity and variable lymph node metastases status strongly suggest evaluating more than one sample and, if available, metastatic foci for routinely HER2 testing.

Human epidermal growth factor receptor-2 expression in primary and metastatic gastric cancer

BACKGROUND

Amplification and overexpression of human epidermal growth factor receptor-2 (HER-2) has been shown in subgroups of gastric cancer, correlated to more aggressive disease and predictive for the treatment with HER-2 antibodies. In this study, we examined the prognostic value of HER-2 expression in primary gastric cancer and in associated lymph node metastases and confirmed the role of HER-2 in tumor angiogenesis by examining vascular endothelial growth factor (VEGF) expression.

METHODS

Immunohistochemistry was used to detect HER-2 and VEGF expression in 110 gastric cancer specimens and associated lymph node metastases and in 96 specimens of normal gastric mucosa.

RESULTS

The expression level of HER-2 in gastric tissues was significantly higher than in normal tissues (19.1 % vs. 8.3 %; P < 0.05). HER-2 overexpression was homogeneous in primary gastric cancer and metastatic lymph nodes (P = 0.607). There was a significant positive correlation of HER-2 expression and VEGF expression (P = 0.007). HER-2 overexpression in primary tumor correlated with lymph node metastasis, distant metastasis, and American Joint Committee on Cancer (AJCC) stage. Cox regression multivariate analyses confirmed that tumor size, histological grade, lymph node ratio, AJCC stage, chemotherapy, and HER-2 expression were all prognostic factors. Patients with HER-2 positivity in both primary and metastatic tissues (+/+) had the poorest survival (OS, 12.5 months; DFS, 11.0 months) (P < 0.01).

CONCLUSIONS

HER-2 was significantly overexpressed in gastric cancer versus normal tissue and correlated with VEGF expression. HER-2 in tumor or lymph nodes was an independent negative prognostic factor.

Heterogeneity of ERBB2 in gastric carcinomas: a study of tissue microarray and matched primary and metastatic carcinomas

Trastuzumab in association with systemic cytotoxic chemotherapy is a therapeutic option for patients with advanced or metastatic ERBB2+ gastric carcinoma. The status of the ERBB2 overexpression or gene amplification is an important predictive marker in gastric cancer. However, it is controversial whether the primary tumor is representative of distant metastases in terms of ERBB2 status. Quadruplicated tissue microarrays from formalin-fixed paraffin-embedded tissues from 498 advanced primary gastric carcinomas and 97 matched metastatic lymph nodes were investigated by immunohistochemistry with HercepTest and silver in situ hybridization. For further comparison, another set of 41 paired primary and distant metastatic gastric carcinomas were also tested. Intratumoral heterogeneity was defined as different results between tissue microarray cores. ERBB2-positivity was observed in 52 gastric carcinomas (10%) and was not associated with recurrence of disease or survival of patients. In ERBB2-positive primary gastric carcinomas, heterogeneous ERBB2 overexpression was observed in 21/63 (33%) gastric carcinomas and heterogeneous ERBB2 gene amplification in 14/62 (23%) cases. Repeated immunohistochemistry and silver in situ hybridization in representative paraffin tumor blocks confirmed focal ERBB2 overexpression and ERBB2 gene amplification and did not change the final results. Discrepancies in ERBB2 results between primary and paired metastatic lymph nodes were observed in 11% of cases by immunohistochemistry and 7% by silver in situ hybridization. Out of the 41 paired primary and distant metastases, 5 (12%) cases were ERBB2-positive, and discrepancy was observed in one case. Intratumoral heterogeneity and discrepant ERBB2 results in primary and metastatic tumor are not uncommon in gastric carcinoma. Results of silver in situ hybridization showed less frequent heterogeneity compared with immunohistochemistry. Wherever possible, ERBB2 immunohistochemistry testing should be performed in both primary and distant metastatic sites.

Assessment of HER2 gene amplification in adenocarcinomas of the stomach or gastroesophageal junction in the INT-0116/SWOG9008 clinical trial

BACKGROUND

Trastuzumab has been approved for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic gastric carcinoma; however, relatively little is known about the role of HER2 in the natural history of this disease.

PATIENTS AND METHODS

Patients enrolled in the INT-0116/SWOG9008 phase III gastric cancer clinical trial with available tissue specimens were retrospectively evaluated for HER2 gene amplification by FISH and overexpression by immunohistochemistry (IHC). The original trial was designed to evaluate the benefit of postoperative chemoradiation compared with surgery alone.

RESULTS

HER2 gene amplification rate by FISH was 10.9% among 258 patients evaluated. HER2 overexpression rate by IHC was 12.2% among 148 patients evaluated, with 90% agreement between FISH and IHC. There was a significant interaction between HER2 amplification and treatment with respect to both disease-free survival (DFS) (P = 0.020) and overall survival (OS) (P = 0.034). Among patients with HER2-non-amplified cancers, treated patients had a median OS of 44 months compared with 24 months in the surgery-only arm (P = 0.003). Among patients with HER2-amplified cancers, there was no significant difference in survival based on treatment arm. HER2 status was not a prognostic marker among patients who received no postoperative chemoradiation.

CONCLUSION

Patients lacking HER2 amplification benefited from treatment as indicated by both DFS and OS.

CLINICAL TRIAL

INT-0116/SWOG9008 phase III.

Amplification of the human epidermal growth factor receptor 2 gene in differentiated thyroid cancer correlates with telomere shortening

The human epidermal growth factor receptor 2 (HER2) proto-oncogene plays an important role in the development and progression of breast and gastric cancer. Monitoring of the HER2 status and treatment with trastuzumab was performed initially in breast cancer, and subsequently in gastric cancer. However, the HER2 status of thyroid cancer remains unexplored. Telomere alteration and telomerase activity have been observed in most human cancers and are known to be a feature of malignancy. The aims of this study were to clarify the HER2 status of thyroid cancer and to examine any correlations to various characteristics of malignancy. We investigated 69 cases of differentiated thyroid cancers with reference to: i) telomere length as measured using tissue quantitative fluorescence in situ hybridization (Q-FISH), ii) expression of human telomerase reverse transcriptase (hTERT) as determined by immunohistochemistry (IHC), and iii) overexpression of the HER2 protein as determined by IHC and amplification of the HER2 gene as determined by fluorescence in situ hybridization (FISH). The telomeres of thyroid cancers, especially follicular carcinomas, were significantly shorter compared to those of adjacent normal tissues. Positivity for hTERT expression and HER2 amplification were observed in approximately 70 and 22% of thyroid cancers, respectively. Our data demonstrated that telomeres in HER2-positive cancers were significantly shorter compared to those in HER2-negative cancers. These results suggest that highly malignant differentiated thyroid cancer can be detected by monitoring HER2 status and telomere shortening, and that trastuzumab therapy may be effective for refractory thyroid cancer.

Molecular targeted agents for gastric cancer: a step forward towards personalized therapy

Gastric cancer (GC) represents a major cancer burden worldwide, and remains the second leading cause of cancer-related death. Due to its insidious nature, presentation is usually late and often carries a poor prognosis. Despite having improved treatment modalities over the last decade, for most patients only modest improvements have been seen in overall survival. Recent progress in understanding the molecular biology of GC and its signaling pathways, offers the hope of clinically significant promising advances for selected groups of patients. Patients with Her-2 overexpression or amplification have experienced benefit from the integration of monoclonal antibodies such as trastuzumab to the standard chemotherapy. Additionally, drugs targeting angiogenesis (bevacizumab, sorafenib, sunitinib) are under investigation and other targeted agents such as mTOR inhibitors, anti c-MET, polo-like kinase 1 inhibitors are in preclinical or early clinical development. Patient selection and the development of reliable biomarkers to accurately select patients most likely to benefit from these tailored therapies is now key. Future trials should focus on these advances to optimize the treatment for GC patients. This article will review recent progress and current status of targeted agents in GC.

HER2 expression and its clinicopathological features in resectable gastric cancer

BACKGROUND

A recent randomized controlled trial (Trastuzumab for Gastric Cancer [ToGA] study) established standard scoring criteria of human epidermal growth factor receptor 2 (HER2) for gastric cancer and demonstrated the efficacy of trastuzumab for treating metastatic gastric cancer. The aim of the present study was to evaluate the frequency of HER2-positive cases by application of the standard criteria in patients with resectable gastric cancer and to examine the relationships between HER2 expression and prognosis, mucin phenotype, p53 status, and clinicopathological features.

METHODS

A total of 213 patients were included in this retrospective study. All tumor samples were examined for HER2 expression by immunohistochemistry (IHC), HER2 amplification by in situ hybridization, and mucin and p53 expression by staining for CD10, MUC2, MUC5AC, MUC6, and p53.

RESULTS

HER2-positive tumors were identified in 25 patients (11.7 %). HER2-positive cases were more frequently found in men, older patients, and in the intestinal histological type (P = 0.0048, 0.0309, and <0.0001, respectively). Although no association was found between HER2 overexpression and mucin phenotype, the expression of CD10 and p53 was significantly correlated with HER2 positivity (P = 0.0079 and 0.013). The overall survival of HER2-negative and -positive patients was not significantly different. However, in patients with stage III/IV, overall survival was worse in HER2-positive patients (P = 0.0149). In a comparison between dual-color in situ hybridization (DISH) and fluorescence in situ hybridization (FISH), four IHC2+/3+ cases that were DISH-positive were judged as negative by FISH.

CONCLUSIONS

Our study indicated that HER2 expression was less frequent in resectable gastric cancer than in metastatic gastric cancer. The impact of HER2 expression on survival was limited. DISH was superior to FISH for evaluating cases with limited HER2 expression.

A large cohort of consecutive patients confirmed frequent HER2 positivity in gastric carcinomas with advanced stages

BACKGROUND

Trastuzumab in association with systemic cytotoxic chemotherapy is the standard of care for patients with advanced HER2-positive gastric carcinoma (GC). However, HER2 as a prognostic factor in GC remains controversial.

METHODS

HER2 overexpression and amplification was evaluated by immunohistochemistry (IHC) and silver in situ hybridization (SISH) in 2,798 GCs obtained from 2,727 gastrectomy and 71 open/laparoscopic biopsy specimens from patients with peritoneal seeding. Regional heterogeneity was defined as the proportion of tumor cells showing membranous staining in 10-70 % of tumor cells. Genetic heterogeneity was determined by the existence of HER2/CEP17 ratio higher than 2.0 in >5 to <50 % of tumor cells.

RESULTS

In IHC, 184 cases (6.6 %) were 3+ and 44 cases (1.6 %) were 2+. Of 44 HER2 2+ cases, SISH showed HER2 gene amplification in 21 cases (47.7 %), chromosome 17 polysomy in six cases (13.6 %), and genetic heterogeneity in five cases (11.4 %). HER2 positivity found in 7.3 % of GCs was significantly associated with older age, male gender, intestinal histology, upper third in location, higher lymph node stage (p < .002), and advanced AJCC stage (p = .033). Regional heterogeneity of HER2 was closely associated with 2+ (70.5 vs 42.9 % in 3+, p = .001) and diffuse or mixed histologic type (p = .005).

CONCLUSIONS

Regional heterogeneity of HER2 expression was closely associated with weak HER2 overexpression (2+) and with diffuse or mixed histology. Polysomy of chromosome 17 would be an important cause of HER2 2+ in IHC. Frequent HER2 positivity observed in GCs with advanced stages suggests that HER2 may be involved in tumor progression and poor prognosis.

Prognosis significance of HER-2/neu overexpression/amplification in Chinese patients with curatively resected gastric cancer after the ToGA clinical trial

Background

HER-2/neu-targeted therapy has been successfully used in advanced gastric cancer, but the role of HER-2/neu in the prognosis of gastric cancer is not yet clear. In this study, we investigated the correlation between HER-2/neu expression and amplification as well as their association with clinic outcomes in patients with curatively resected gastric cancer.

Methods

We constructed tissue microarray blocks containing >70% of gastric cancer tissue and matched adjacent normal gastric tissue for 227 patients. Expression of the HER-2/neu protein in these specimens was analyzed using immunohistochemical staining. Amplification of HER-2/neu was also analyzed for the same samples using fluorescence in situ hybridization. Data on clinicopathological features and relevant prognostic factors in these patients were analyzed.

Results

Of the 227 gastric cancer samples, 11.89% were positive for HER-2/neu overexpression/amplification under the new scoring system. HER-2/neu overexpression/amplification was closely correlated to the Lauren type, degree of differentiation, tumor size and lymph node metastasis. HER-2/neu overexpression/amplification predicted poor survival in univariate analysis but not in a Cox proportional hazards model.

Conclusion

HER-2/neu overexpression/amplification was not an independent predictor for survival in patients with curatively resected gastric cancer.

Metachronous liver and bone metastasis from small early gastric carcinoma without lymph node involvement: A case report

A 65-year-old man was referred to our Hospital for examination of gastric cancer initially diagnosed by medical check-up. Esophagogastroduodenoscopy demonstrated a superficial depressed-type gastric cancer in the antrum, and abdominal computed tomography showed no evidence of distant metastases. A tumor measuring 11 mm in diameter was removed by endoscopic submucosal dissection (ESD). Since histological examinations of ESD specimens showed a well-differentiated adenocarcinoma invading the submucosal layer with lymphatic invasion, the patient subsequently underwent laparoscopy-assisted distal gastrectomy with regional lymph node dissection, resulting in no residual carcinoma and no lymph node metastasis. The patient developed solitary liver metastasis one year later and was treated with trastuzumab plus capecitabine/cisplatin since results of the immunohistochemical analysis of the resected specimens demonstrated overexpression of the human epidermal growth factor receptor 2 (HER2). The patient was alive 12 months after surgical resection of the liver metastasis and subsequently developed bone metastasis. Controversy remains over the role of HER2 status as a prognostic factor in gastric cancer. However, it has been generally reported that HER2 overexpression correlates with aggressive biological behavior and poor prognosis. HER2 overexpression is a potentially useful predictive factor for tumor recurrence and poor prognosis even in early gastric cancer cases.

Molecular Pathology of Gastrointestinal Cancer

The purpose of this review is to discuss important molecular changes that aid decision making in patient management and play a role in emerging treatment strategies for gastrointestinal malignancies. Although screening and surveillance practices have had an impact on the natural history of some tumor types, gastric carcinoma is a major cause of morbidity and mortality in high prevalence regions and colorectal carcinoma is still the fourth leading cause of cancer related death in the United States.

Chromogenic in situ hybridization (CISH) to detect HER2 gene amplification in breast and gastric cancer: comparison with immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH)

The chromogenic in situ hybridization (CISH) assay, designed to detect the amplification of the HER2 gene in formalin-fixed, paraffin-embedded (FFPE) breast cancer (BC) and gastric cancer (GC) tissue specimens, was evaluated in 125 FFPE BC cases and 198 FFPE GC cases for which the HER2 status had been predetermined using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). In the 125 BC cases and the 198 gastric cases, we found a very good concordance (98.4% and 99.0%, respectively) between CISH and FISH. In particular, we evaluated the polysomy cases, as these cases often have ambiguous treatment options in clinical practice. The polysomy of chromosome 17 was defined as the presence of three or more CEP17 signals in at least 10% of the tumor cells. In the 50 BC cases and 54 GC cases displaying chromosome 17 polysomy, the concordance between FISH and CISH was 98.0% and 98.1%, respectively. These results indicate that CISH could provide an accurate and practical alternative to FISH for the clinical diagnosis of HER2 gene amplification in FFPE BC and FFPE GC samples.