HER2 Status In Gastric Cancer Research Articles

Predicting human epidermal growth factor receptor 2 status of patients with gastric cancer by computed tomography and clinical features.

There have been no studies on predicting human epidermal growth factor receptor 2 (HER2) status in patients with resectable gastric cancer (GC) in the neoadjuvant and perioperative settings. We aimed to investigate the use of preoperative contrast-enhanced computed tomography (CECT) imaging features combined with clinical characteristics for predicting HER2 expression in GC. We retrospectively enrolled 301 patients with GC who underwent curative resection and preoperative CECT. HER2 status was confirmed by postoperative immunohistochemical analysis with or without fluorescence in situ hybridization. A prediction model was developed using CECT imaging features and clinical characteristics that were independently associated with HER2 status using multivariate logistic regression analysis. Receiver operating characteristic curves were constructed and the performance of the prediction model was evaluated. The bootstrap method was used for internal validation. Three CECT imaging features and one serum tumor marker were independently associated with HER2 status in GC: enhancement ratio in the arterial phase (odds ratio [OR] = 4.535; 95% confidence interval [CI], 2.220-9.264), intratumoral necrosis (OR = 2.64; 95% CI, 1.180-5.258), tumor margin (OR = 3.773; 95% CI, 1.968-7.235), and cancer antigen 125 (CA125) level (OR = 5.551; 95% CI, 1.361-22.651). A prediction model derived from these variables showed an area under the receiver operating characteristic curve of 0.802 (95% CI, 0.740-0.864) for predicting HER2 status in GC. The established model was stable, and the parameters were accurately estimated. Enhancement ratio in the arterial phase, intratumoral necrosis, tumor margin, and CA125 levels were independently associated with HER2 status in GC. The prediction model derived from these factors may be used preoperatively to estimate HER2 status in GC and guide clinical treatment.

Development and validation of multivariate models integrating preoperative clinicopathological and radiographic findings to predict HER2 status in gastric cancer

The combination of trastuzumab and chemotherapy is recommended as first-line therapy for patients with human epidermal growth factor receptor 2 (HER2) positive advanced gastric cancers (GCs). Successful trastuzumab-induced targeted therapy should be based on the assessment of HER2 overexpression. This study aimed to evaluate the feasibility of multivariate models based on hematological parameters, endoscopic biopsy, and computed tomography (CT) findings for assessing HER2 overexpression in GC. This retrospective study included 183 patients with GC, and they were divided into primary (n = 137) and validation (n = 46) cohorts at a ratio of 3:1. Hematological parameters, endoscopic biopsy, CT morphological characteristics, and CT value-related and texture parameters of all patients were collected and analyzed. The mean corpuscular hemoglobin concentration value, morphological type, 3 CT value-related parameters, and 22 texture parameters in three contrast-enhanced phases differed significantly between the two groups (all p < 0.05). Multivariate models based on the regression analysis and support vector machine algorithm achieved areas under the curve of 0.818 and 0.879 in the primary cohort, respectively. The combination of hematological parameters, CT morphological characteristics, CT value-related and texture parameters could predict HER2 overexpression in GCs with satisfactory diagnostic efficiency. The decision curve analysis confirmed the clinical utility.

Pre-Clinical Study of the [18F]AlF-Labeled HER2 Affibody for Non-Invasive HER2 Detection in Gastric Cancer.

Human epidermal growth factor receptor 2 (HER2) is an important biomarker in gastric cancer (GC) and directly influences the therapeutic effect. Fluorine is firmly bound to Al3+ forming [18F]AlF-1,4,7-triazacyclononanetriacetic acid (NOTA)-HER2 affibody is a promising radiolabeled tracer that can monitor the changes of HER2 expression combining the advantages of simple preparation and the properties of 18F. The aim of this study was to develop a quick method for the synthesis of [18F]AlF-NOTA-HER2 affibody and evaluate its utility for HER2+ GC imaging in mouse models. Moreover, 68Ga-NOTA-HER2 affibody imaging was also performed to highlight the superiority of [18F]AlF-NOTA-HER2 affibody imaging in resolution. The HER2 affibody was conjugated with NOTA and labeled using 18F based on the complexation of [18F]AlF by NOTA. Its quality control and stability were performed by high-pressure liquid chromatography (HPLC). The molecular specificity and binding affinity of the novel radiotracer were evaluated in the GC cell line with HER2 overexpression (NCI-N87) and negative expression (MKN74). Distribution studies and PET/CT imaging were performed in mouse models. 68Ga-NOTA-HER2 affibody PET/CT imaging was also performed. [18F]AlF-NOTA-HER2 affibody was efficiently prepared within 30 min with a non-decay-corrected maximum yield of 32.69% and a radiochemical purity of more than 98%. [18F]AlF-NOTA-HER2 affibody was highly stable in incubation medium for 4 h in vitro and in the blood of nude mice at 30 min post-injection (p.i.). In vitro studies revealed specific binding and high binding affinity of the probe in NCI-N87 cells, while no binding was seen in MKN74 cells. PET imaging showed that NCI-N87 xenografts were differentiated from MKN74 xenografts with excellent contrast and low abdominal background, which was confirmed by the distribution results. High-level accumulation of the [18F]AlF-NOTA-HER2 affibody in HER2+ tumors was blocked by excess unlabeled NOTA-HER2 affibody. [18F]AlF-NOTA-HER2 affibody has a higher image resolution than that of 68Ga-NOTA-HER2 affibody. [18F]AlF-NOTA-HER2 affibody could be produced facilely with high radiochemical yield and may serve as a novel molecular probe with tremendous clinical potential for the non-invasive whole-body detection of the HER2 status in GC with good image contrast and resolution. This method could provide an in vivo understanding of GC biology that will ultimately guide the accurate diagnosis and treatment of GC.

Abstract 2277: HER2 copy number variation detected by next-generation sequencing reveals HER2 expression heterogeneity in gastric cancer

Abstract Purpose: Human epidermal growth factor receptor 2 (HER2) is an effective therapeutic target in gastric cancer (GC). Both HER2-positive and HER2-low GC could benefit from HER2 inhibitors including trastuzumab and trastuzumab deruxtecan. However, it is difficult to accurately evaluate HER2 status by immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH), owing to intra-tumor heterogeneity and the experience of the pathologist. Herein, we investigated whether HER2 copy number variation (CNV) detected by next-generation sequencing (NGS) could assist in accurately determining the HER2 status. Methods: We analyzed HER2 CNV on tumor specimens from 212 GC patients using NGS in a CLIA-certified laboratory. The log ratio of HER2 &amp;gt;0.7 was defined as amplification and log ratio of 0.4 to 0.7 was defined as low amplification. HER2 expression was examined in all 212 GC patients by IHC and HER2 amplification was assessed in 22 patients by FISH. Results: Of 212 patients, three had HER2 amplification and three had low HER2 amplification. Among three patients with HER2 amplification, all were found to have strong positive HER2 expression (IHC 3+). Among three patients with HER2 low amplification, two patients had HER2 IHC 2+ (including one HER2 FISH-negative and one HER2 FISH-unknown) and one patient had HER2 IHC 1+. Moreover, two patients were found HER2 IHC 3+ in whom without HER2 amplification. Of the two, one was most HER2 IHC 2+ with focal tumor IHC 3+, and the HER2 CNV was close to the threshold (log ratio of HER2: 0.2882). The reason for the discordance may be related to intra-tumor heterogeneity. HER2 copy number will be diluted in samples with focal 3+ and NGS reflects the relative global nature of the tumor specimens. No HER2 IHC-negative cases (N=99) showed HER2 CNV, suggesting that HER2 CNV detected by NGS has specificity of 100%. Conclusions: HER2 CNV detected by NGS could predicts HER2 status in GC and more accurately stratified GC patients with either HER2-positive or HER2-low. Thus, we can screen out those who can truly benefit from trastuzumab and trastuzumab deruxtecan (eg. DS-8201). Prospective cohorts are needed to validate HER2 CNV detected by NGS for predicting response to anti-HER2 therapy. Citation Format: Xiaotian Zhang, Hui Chen, Xiaochen Zhao, Jie Wang, Yuezong Bai. HER2 copy number variation detected by next-generation sequencing reveals HER2 expression heterogeneity in gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2277.

Dual-Energy CT-Based Nomogram for Decoding HER2 Status in Patients With Gastric Cancer.

OBJECTIVE. The purpose of this study was to develop and evaluate a dual-energy CT (DECT)-based nomogram for noninvasive identification of the status of human epidermal growth factor receptor 2 (HER2; also known as ERBB2) expression in gastric cancer (GC). MATERIALS AND METHODS. A total of 206 patients with histologically proven GC who underwent pretreatment DECT were retrospectively recruited and randomly allocated to a training cohort (n = 144) or a test cohort (n = 62). Information on clinical characteristics, qualitative imaging features, and quantitative DECT parameters was collected. Univariate analysis and multivariate logistic regression were implemented to screen independent predictors of HER2 status. An individualized nomogram was built, and its discrimination, calibration, and clinical usefulness were assessed. RESULTS. Tumor location, the iodine concentration of the tumor in the venous phase, and the normalized iodine concentration of the tumor in the venous phase were significant factors predictive of HER2 status (all p < .05). After these three indicators were integrated, the proposed nomogram showed a favorable diagnostic performance, with AUCs of 0.807 (95% CI, 0.718-0.897) in the training cohort and 0.815 (95% CI, 0.661-0.968) in the test cohort. The nomogram showed a preferable fitting (all p > .05 by the Hosmer-Lemeshow test) and would offer more net benefits than simple default strategies within a wide range of threshold probabilities in both cohorts. CONCLUSION. The DECT-based nomogram has great application potential in terms of detecting HER2 status in GC, and can serve as a novel substitute for invasive testing.

Clinicopathological factors associated with HER2-positive gastric cancer: A meta-analysis.

Background:The treatment of patients with advanced gastric cancer remains a most challenging task in the clinical practice. Recently, targeted therapies have significantly impacted the treatment strategy for many common malignancies. The use of trastuzumab, a monoclonal antibody against human epidermal growth factor receptor 2 (HER2; also known as ERBB2), plus chemotherapy proved to improve median overall survival in patients with advanced gastric cancer, compared with chemotherapy alone in Trastuzumab for Gastric Cancer (ToGA) trial. However, the prognostic value of HER2 status in gastric cancer remains controversial. Therefore, the aim of this study was to investigate the clinical pathology significance of HER2 overexpression in resectable gastric cancer for selecting the right patients with gastric cancer who may benefit from trastuzumab treatment.Methods:Publications reported the clinicopathological factors associated with HER2 status in gastric cancer from 2012 to 2017 were collected. The literature databases, such as “Cochrane Library”, “Sciencedirect”, “Springer”, “PubMed”, “Embase”, were extensively searched to retrieve the clinical studies of HER2 expression in gastric cancer. The major outcomes measures were odds ratios (ORs) and their 95% CIs. Statistical analysis was carried out by Revman software 5.3. The Newcastle–Ottawa scale was used to assess the quality of evidence.Result:Fifteen studies met our inclusion criteria. This study demonstrated that the pooled OR for HER2 positivity was associated with being male (OR: 1.42; 95% CI: 1.23–1.64), well/moderately differentiated tumor (OR: 2.76; 95% CI: 1.72–4.45), and for intestinal-type tumor (OR: 0.31; 95% CI: 0.25–0.38). However, it had no correlation with depth of tumor (P = .07), venous invasion (P = .82), and lymphovascular invasion (P = .24).Conclusion:HER2-positive expression was associated with male gender, intestinal type, and well/moderate cell differentiation. We recommend that those gastric cancer patients who may benefit from trastuzumab treatment should be subjected to targeted therapies. However, detecting HER2 status may contribute to the target therapy for gastric carcinoma using trastuzumab. This would be strengthened by further studies incorporating comorbidity data, and outcomes from centralized programs.

HER2 overexpression and amplification in patients with colorectal cancer: a large-scale retrospective study in Chinese population.

e15099 Background: Recent studies have shown that human epidermal growth factor receptor 2 (HER2) overexpression or amplification may be a potentially predictive factor for anti-HER2 response and anti-EGFR resistance in colorectal cancer (CRC). However, the prevalence of HER2 positivity in CRC patients and its correlation with clinicopathologic features are not clear. Methods: HER2 expression was tested by immunohistochemistry (IHC) in 4,913 consecutive patients with CRC treated with surgical resection of primary tumor during 2011-2014 in our institution. The formalin-fixed, paraffin-embedded samples of the primary tumors were used. Dual color silver-enhanced in situ hybridization (DISH) was performed in all IHC 3+/2+ cases and randomly selected IHC 1+/0 cases subsequently. The scoring criteria of HER2 status in gastric cancer was used. Results: HER2 positivity was found in 160 (3.3%) out of 4,913 cases of CRC. Among them, 68 cases were IHC 3+, while 92 cases were IHC 2+ and DISH+. 157 cases (3.2%) were HER2 amplified determined by DISH, including 66 (97.1%, 66/68) IHC 3+ and 92 (35.6%, 92/258) IHC 2+ cases. None of the 50 cases of IHC 1+/0 was HER2 amplified. HER2 positivity was correlated with perineural invasion, vascular invasion, lymph node metastases, and higher TNM stage. HER2 positivity was more common in younger patients ( &lt; 60 year old). Only one HER2 positive case had mismatch repair protein (MMR) deficiency. HER2 positivity was found not related to tumor location. Conclusions: To our knowledge, this is the largest study of HER2 status in Asian patients with CRC. HER2 overexpression or amplification of tumor cells occurred in a small number of patients with CRC. HER2 positivity was related to unfavorable prognostic factors, more common in younger patients and rare in MMR deficiency cases. The further study of molecular heterogeneity of HER2 expression or amplification in patients with CRC was ongoing.

Serum HER2 level during chemotherapy as a biomarker for advanced gastric cancer.

29 Background: Recent studies showed that serum HER2 levels correlated with tissue HER2 status in gastric cancer. The aim of this prospective study (UMIN000006442, 000006445) was to investigate changes in serum HER2 levels and tissue HER2 status during chemotherapy for advanced gastric cancer (AGC). Methods: Chemotherapy (Capecitabine and cisplatin) with and without trastuzumab was administered to patients with HER2-positive and HER2-negative AGC, respectively. Serum HER2 level was measured using chemiluminescense immunoassay (CLIA) at 4 points: at the initial diagnosis, after two cycles of chemotherapy, at the initial evaluation of tumor response, and at the time of progression. If possible, second biopsy was performed at progression to compare tissue HER2 status before and after chemotherapy. Results: Thirty-three patients (14 HER2-positive and 19 HER2-negative) with a median age of 67 years (range 51-80) were recruited. The median baseline serum HER2 level of the HER2-positive group was significantly higher than that of the HER2-negative group (p = 0.038, 12.0 ng/ml (range 6.5-148.0) and 8.2 ng/ml (4.5-27.2), respectively). A Decrease in serum HER2 level was correlated with tumor response in the HER2-positive group while it was not in the HER2-negative group. Tissue samples at the time of progression were obtained in 6 out of 19 HER2-negative cases. Of these, serum HER2 level elevated at progression in 4 cases, and tissue HER2 status has turned to positive at tumor progression in one case. In the HER2-positive group, tissue samples at tumor progression were obtained in 2 cases, and both showed HER2-positive result, same as the initial diagnosis. Conclusions: Serum HER2 could be useful as a response indicator in HER2-positive AGC. Tissue HER2 status may change from negative to positive over time and serum HER2 has a possibility to predict it. Further studies are needed to confirm these findings. Clinical trial information: UMIN000006442,000006445.

Serum HER2 as a predictive biomarker for tissue HER2 status and prognosis in patients with gastric cancer.

AIMTo investigate the association between serum human epidermal growth factor receptor 2 (HER2) extracellular domain (ECD) and tissue HER2 status, and the prognostic value of serum HER2 ECD in patients with gastric cancer.METHODSA total of 239 patients with gastric cancer were enrolled from December 2012 to June 2013. Serum HER2 ECD was determined by chemiluminescent assay, and tissue HER2 status was evaluated by immunohistochemistry and fluorescence in situ hybridization assay. A receiver operating characteristic (ROC) curve was plotted to identify the optimal cut-off value for serum HER2 ECD assay for predicting survival in gastric cancer patients.RESULTSSerum HER2 ECD was significantly correlated with tissue HER2 status (P < 0.001), tumor size (P < 0.001), and intestinal type of gastric cancer (P = 0.021). Serum HER2 ECD levels differed significantly between patients with HER2-positive tissue expression and those with HER2-negative tissue expression. ROC analysis yielded an area under the curve value of 0.79 (95%CI: 0.71-0.87, P < 0.001), with a sensitivity and specificity of 0.54 (95%CI: 0.37-0.70) and 0.93 (95%CI: 0.88-0.96), respectively. With a cut-off value of 24.75 ng/mL, high serum HER2 ECD had a negative impact on overall survival of the patients (HR: 1.93, 95%CI: 1.32-4.38, P = 0.006).CONCLUSIONSerum HER2 ECD could be a highly specific surrogate biomarker for tissue HER2 status in gastric cancer. Optimal cut-off criteria for predicting survival should be established.

Serum HER2 as an adjunct to assess HER2 status for advanced gastric cancer: A prospective multicenter trial (SHERLOCK)

Background: Intratumoral human epidermal growth factor receptor 2 (HER2) heterogeneity of gastric cancer can be an obstacle to accurate HER2 assessment. Serum HER2, concentrations of the HER2 extracellular domain shed into the bloodstream, has a potential to compensate HER2 immunohistochemistry (IHC) but has not been scrutinized in gastric cancer. This study sought to explore the clinical utility of serum HER2 in gastric cancer.Methods: We performed a prospective multicenter trial (SHERLOCK trial) involving patients with all-stage gastric or gastro-esophageal junction cancer. Serum HER2 was measured using direct chemiluminescence while tissue HER2 status was determined using IHC and fluorescent in situ hybridization. For stage IV cases, concordance between local and central laboratories in tissue HER2 assessment was also evaluated.Results: Of 224 patients enrolled, both tissue HER2 status and serum HER2 levels were successfully determined in 212 patients and 21% (45/212) were tissue HER2-positive. Serum HER2 levels, ranged from 4.5 to 148.0 ng/ml (median 10.3), correlated with tissue HER2 status (p = 0.003). At a cut-off level of 28.0 ng/ml determined by receiver operating characteristics analysis, sensitivity, specificity, positive and negative predictive values of serum HER2 were 22.6%, 100%, 100% and 82.3%, respectively. All nine cases with elevated serum HER2 were tissue HER2-positive stage IV cases. Among 61 stage IV cases, the agreement rate for IHC scoring between the local and the central laboratories was 82% and tissue HER2 judgment was conflicting in five (8.2%) cases. Of these five cases, four were confirmed as false-negative and two of these four patients demonstrated elevated serum HER2.Conclusions: Serum HER2 levels correlated with tissue HER2 status in gastric cancer. Although the low sensitivity is a drawback, serum HER2 might be a useful adjunct tool to detect tissue HER2 false-negative gastric cancer.

Association between HER2 status in gastric cancer and clinicopathological features: a retrospective study using whole-tissue sections.

BackgroundGastric cancer is usually diagnosed in an advanced stage of disease and treatment options are sparse. Trastuzumab was recently approved for metastatic or locally advanced carcinomas arising in the stomach or in the gastroesophageal junction in patients with HER2-positive tumors. However, data on the frequency of HER2-positive cases among Brazilian patients are limited. Our aim was to characterize HER2 protein and gene status in a series of Brazilian patients with gastric cancer and to evaluate its association with clinicopathological data.MethodsHistological slides from 124 primary gastrectomies were reviewed and their pathological reports were retrieved from the files at a Brazilian university hospital. Automated immunohistochemistry for HER2 was performed on whole-tissue sections from each tumor. HER2-equivocal cases by immunohistochemistry were submitted to automated dual in situ hybridization for gene amplification evaluation. HER2 status was confronted with clinicopathological parameters in order to assess statistically significant associations.ResultsImmunohistochemistry analysis revealed that 13/124 cases (10.5 %) were HER2 positive (3+), 10/124 cases (8.1 %) were equivocal (2+) and 101/124 cases (81.4 %) were negative, being 7 cases 1+. None of the equivocal cases showed gene amplification. The overall HER2 positivity rate was 10.5 %. There was an association between HER2 expression and Laurén’s intestinal histological subtype (P = 0.048), well to moderately differentiated tumors (P = 0.004) and presence of lymphovascular invasion (P = 0.031). No association was found between HER2 status and tumor topography.ConclusionsConfronted with data published by other authors, the lower percentage of HER2-positive cases found in our series might be partially explained by the lower frequency of tumors arising at the gastroesophageal junction in comparison with distal gastric carcinomas in Brazilian patients. This could also account for the lack of statistically significant association between HER2 status and tumor topography in our study.

Correlation between apparent diffusion coefficients and HER2 status in gastric cancers: pilot study.

BackgroundTo evaluate whether apparent diffusion coefficient (ADC) value of gastric cancer obtained from diffusion weighted imaging (DWI) correlates with the HER2 status.MethodsForty-five patients, who had been diagnosed with gastric cancer through biopsy, were enrolled in this IRB-approved study. Each patient underwent a DWI (b values: 0 and 1,000 sec/mm2) prior to surgery (curative gastrectomy or palliative resection). Postoperative microscopic findings, HER2 status by immunohistochemical analysis and fluorescence in situ hybridization (FISH) were obtained. HER2 status was compared among gastric cancers with various histopathological features using the chi square test. The ADC values of gastric cancers with positive and negative HER2 were compared using the student t test.ResultsA weak yet significant correlation was observed between the mean ADC values and HER2 status (r = 0.312, P = 0.037) and scores (r = 0.419, P = 0.004). The mean ADC value of HER2-positive gastric cancers was significantly higher than those of HER2-negative tumors (1.211 vs. 0.984 mm2/s, P = 0.020). The minimal ADC value of HER2-positive gastric cancers was significantly higher than those of HER2-negative tumors (1.105 vs. 0.905 × 10−3 mm2/s, P = 0.036).ConclusionsIn this pilot study, we have demonstrated that the ADC values of gastric cancer correlate with the HER2 status. Future research is warranted to see if DWI can predict HER2 status and help in tailoring therapy for gastric cancer.

Serum HER2 Is a Potential Surrogate for Tissue HER2 Status in Gastric Cancer: A Systematic Review and Meta-Analysis.

Determining the expression level of human epidermal growth factor receptor 2 (HER2) in tumor tissue is of great importance for personalized therapy in gastric cancer. Although several studies have investigated whether serum HER2 can serve as a surrogate for tissue HER2 status, results have been inconsistent. We therefore performed a meta-analysis of published clinical studies in an attempt to address this problem. PubMed, Embase, Web of Science, the Cochrane Library and Science Direct were queried for eligible studies that could provide sufficient data to construct 2 × 2 contingency tables. The quality of the studies included in the meta-analysis was assessed in accordance with the revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria. The pooled sensitivity, specificity and diagnostic odds ratio (DOR) were calculated for the eligible studies. The summary receiver operating characteristic (SROC) curve was constructed and the area under the SROC (AUSROC) was used to evaluate overall diagnostic performance. Eight studies comprising a total of 1170 participants were included in our meta-analysis. The pooled sensitivity, specificity and DOR were 0.39 (95% CI: 0.21–0.61), 0.98 (95% CI: 0.87–1.00), and 27 (95% CI: 9–81), respectively. The AUSROC was 0.77 (95% CI: 0.73–0.80) and Deeks funnel plot suggested the absence of publication bias (p = 0.91). Meta-regression analysis indicated that threshold effect was the main source of heterogeneity. Assays for evaluating serum HER2 levels are highly specific and demonstrate moderate diagnostic performance for HER2 tissue status in gastric cancer.

Clinicopathological factors associated with HER2 status in gastric cancer: results from a prospective multicenter observational cohort study in a Japanese population (JFMC44-1101).

BackgroundHuman epidermal growth factor (HER) 2 positivity and its association with clinicopathological factors remain unclear in Japanese gastric cancer (GC) patients. We performed a prospective, multicenter, observational cohort study to evaluate HER2 protein expression and gene amplification in Japanese metastatic and recurrent GC patients, and explored its correlations with clinicopathological features.MethodsHER2 protein expression and gene amplification were centrally assessed in formalin-fixed, paraffin-embedded GC tissue by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Patient information was collected, and associations between clinicopathological factors and HER2 positivity (IHC score 3+ and/or FISH positive) and low HER2 expression (IHC score 0/FISH positive or IHC score 1+/FISH positive) were examined.ResultsFrom September 2011 to June 2012, 1461 patients were registered across 157 sites, and the HER2 status of 1427 patients was evaluated. The rate of HER2 positivity was 21.2 %, whereas the rate of high HER2 expression (IHC score 2+/FISH positive or IHC score 3+) was 15.6 % and that of low HER2 expression was 7.0 %. Multiple logistic regression analysis identified intestinal type, absence of peritoneal metastasis, and hepatic metastasis as significant independent factors related to HER2 positivity. The intestinal type was confirmed to be the GC subtype predominantly associated with lower HER2 expression. Sampling conditions including number of biopsy samples, formalin concentration, and formalin-fixation time did not significantly affect HER2 positivity.ConclusionsHER2 expression in Japanese patients was comparable to that in other populations examined. Intestinal type was an independent factor related to HER2 positivity and low HER2 expression.

Multiplex Ligation-dependent Probe Amplification Can Clarify HER2 Status in Gastric Cancers with "Polysomy 17".

Therapy with trastuzumab confers a survival benefit in HER2 positive advanced gastric and gastroesophageal adenocarcinoma. HER2 status is evaluated by immunohistochemistry (IHC) and in situ hybridization (ISH). An ISH ratio of HER2 to centromere 17 (CEP17) ≥2.0 is considered amplified. This assumes that CEP17 reflects chromosomal copy number. Cases where CEP17 exceeds 3 are classified as polysomic, but it's unknown if they represent true polysomy or centromeric amplification. This has implications on the validity of current ISH criteria. Multiplex ligation-dependent probe amplification (MLPA) allows simultaneous quantification of multiple loci and can distinguish between true polysomy and centromeric amplification. We selected 13 gastric cancers with CEP17 counts ≥3.0 (polyCEP17), and 8 non-polyCEP17 gastric cancer controls. Silver ISH for HER2 and CEP17 were performed and scored by manufacturer guidelines. We also performed an MLPA HER2 assay that evaluates 22 genes on chromosome 17. MLPA identified HER2 amplification in 7 polyCEP17 cases compared to 2 identified by ISH. Overall, 9 of 13 polyCEP17 cases had amplification of the peri-centromeric gene WSB1, compared to 1 of 8 non-polyCEP17 controls (p=0.02). This could account for ISH CEP17 counts ≥3.0. MLPA did not show any cases of complete chromosome 17 duplication and peri-centromeric amplification can explain most cases of ISH polyCEP17. Current ISH criteria may under-diagnose HER2 amplification in polyCEP17 cases due to flawed assumptions about polysomy. MLPA can detect HER2 amplification missed by IHC and ISH, and thus may be an effective ancillary technique in evaluating HER2 status.

A novel gene-protein assay for evaluating HER2 status in gastric cancer: simultaneous analyses of HER2 protein overexpression and gene amplification reveal intratumoral heterogeneity.

Human epidermal growth factor receptor 2 (HER2) protein overexpression and gene amplification are important biomarkers for trastuzumab treatment in breast and gastric cancer patients. Gastric cancer presents high rates of tumor heterogeneity, which may influence the results of HER2 testing. A novel gene-protein assay (GPA) can allow the simultaneous analysis of HER2 protein and gene status on a single slide. Using the tissue microarray technique, the HER2 status of each of 875 gastric cancer cases was evaluated by immunohistochemistry (IHC), brightfield dual-color in situ hybridization (DISH), and GPA. Intratumoral phenotypic and genotypic heterogeneity were evaluated by comparing the HER2 statuses of two tissue cores from each case. There was excellent concordance between GPA and IHC (99.2%), as well as between GPA and DISH results (99.3%). HER2 positivity obtained by GPA was almost identical (99.8%) to the results obtained by IHC and DISH assays. Intratumoral phenotypic heterogeneity was more frequently observed in IHC 2+ cases (63.5%) compared with IHC 3+ cases (28.3%). Phenotypic heterogeneity (48.8%) was more frequently observed than genotypic heterogeneity (26.8%). Tumor heterogeneity was consistently observed from early to advanced stages. HER2-positive gastric cancers presented different levels of HER2 protein expression and gene amplification statuses within the same lesion in almost half the cases examined. Evaluating both phenotypic and genotypic heterogeneity may contribute to a deeper understanding and improved prediction of clinical outcome in gastric cancer patients treated with trastuzumab. This newly established GPA technology may also be useful for developing biomarkers for other molecularly targeted therapies.

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

To determine the HER2 status of gastric adenocarcinomas, by using biopsy and intraoperative specimens. Immunohistochemistry and in situ hybridization were used to examine the HER2 status of 346 gastric cancer biopsy and intraoperative specimens. 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. 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.

O1–002 - Serum HER2 Extracellular Domain Levels and Tissue HER2 Overexpression in Advanced Gastric Cancer Patients

Background: Overexpression of human epidermal growth factor receptor 2 (HER2) is now a crucial biomarker when applying the first line combination chemotherapy containing trastuzumab. Reportedly, tissue HER2 status in gastric cancer shows intra-tumor heterogeneities as well as defferences in results between facilities. In addition, though usefulness of monitoring serum HER2 extracellular domain (HER2ECD) level in metastatic breast cancer has previously reported, little is known about that of gastric cancer. In this study, firstly, we elucidated the tissue HER2 status of inoperable gastric cancers in our hospital. Secondly, we aimed to study the relationship between serum HER2ECD levels and tissue HER2 overexpression in a subset of this cohort. Methods: 1) HER2 status of gastric cancer tissues from 85 patients were analyzed by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) assays in our institution. In 27 patients (Subset A) enrolled in a multi-institutional observational study, tissue HER2 status was independently examined in the other laboratory. 2)In 54 patients (Subset B), serum HER2ECD levels were measured by chemiluminescent immunoassay. Results: Tissue expression of HER2 was positive (IHC3+, or IHC2+ plus FISH+) in 15.0% (13/85) in total, 25.9% (7/27) in subset B, and 24.0 % (13/54) in subset C. One difference in results between laboratories was observed. In subset C, the mean serum HER2ECD level was 19.1 ± 25.1 ng/ml ( 11.3 ± 3.9 ng/ml for tissue HER2 negative, 44.3 ± 43.4 ng/ml for positive pts.). With a cutoff level of 15 ng/ml, the sensitivity of serum HER2ECD levels with respects to HER2 positivity was 77%, specificity 80%, positive predictive value 55.5%, negative predictive value 91.2%. Conclusion: 1) Percentage of HER2 positive metastatic gastric cancer in our institution is almost the same with previous reports, exhibiting some intra-tumor heterogeneities. 2) Although in the small and rather biased population, serum HER2ECD level shows considerable correlation with HER2 overexpression in advanced gastric cancers, warranting a further study about usefulness HER2ECD monitoring during treatment with trastuzumab.

HER2 status in gastric cancers: a retrospective analysis from four Chinese representative clinical centers and assessment of its prognostic significance

BackgroundHER2 has a predictive value in gastric cancer. However, its association with prognosis remains uncertain. The aim of our study was to estimate the HER2-positive rate in Chinese gastric cancers, compare the classical fluorescence in situ hybridization (FISH) method with the novel bright-field dual color silver-enhanced in situ hybridization (DSISH) detection system, and evaluate the relationship between the HER2 status and prognosis. Patients and methodsSeven hundred and twenty-six resected gastric cancers separately from four clinical centers in China were examined for HER2 by immunohistochemistry (IHC), FISH, and DSISH. ResultsThe HER2-positive rate was 13%. The consistency between FISH and DSISH results was high (99%; κ = 0.958; P < 0.001). Tumor heterogeneity and polysomy were the main reasons for inconsistency. There was no significant difference in the 3-year overall survival (OS) between HER2-positive and -negative patients (P = 0.959). Multivariate analysis showed that HER2 was not an independent prognostic factor. Conclusion(s)HER2 overexpression and amplification occur in a significant number of Chinese gastric cancer patients. Given the obvious advantages and high consistency with FISH, DSISH was superior for evaluating HER2 amplification in gastric cancer. HER2 was not a prognostic factor for gastric cancer in our study.

Association between HSP90 and Her2 in Gastric and Gastroesophageal Carcinomas

BackgroundHer2 expression and amplification occurs in a significant subset of gastro-esophageal carcinomas. Her2 is a client protein of molecular chaperones, e.g. heat shock protein (HSP) 90, rendering targeted therapies against Her2/HSP90 an interesting approach. This study aimed to investigate the role and relationship of Her2 and HSP90 in gastric and gastro-esophageal adenocarcinomas.Material and MethodsImmunohistochemical determination of HSP90 and Her2 expression was performed on 347 primary resected tumors. Her2 amplification was additionally determined by fluorescence in situ hybridization for all cases. Expression and amplification results were correlated with pathologic parameters (UICC pTNM category, tumor grading) and survival.ResultsElevated Her2 copy numbers were observed in 87 tumors, 21 of them showing amplification. 174 tumors showed Her2 immunoreactivity/expression. HSP 90 immunoreactivity was found in 125 tumors. There was no difference between gastric carcinomas and carcinomas of the gastroesophageal junction regarding Her2 or HSP90. Both high HSP90 and Her2 expression/amplification were associated with earlier tumor stages (p<0.01), absence of lymph node metastases (p<0.02) and Laurens intestinal type (p<0.001). HSP90 correlated with Her2 expression and amplification (p<0.001 each). Expressions of HSP90 and Her2, but not Her2 amplification were associated with better prognosis (p=0.02; p=0.004; p=0.802). Moreover, Her2 expression was an independent prognostic factor for overall survival in the subgroup of gastric carcinoma patients (p=0.014) besides pT category, pN category and distant metastases.ConclusionHer2 expression and gene amplification occurred in a significant subset of cases. Our results suggest a favorable prognostic impact of Her2 expression. This warrants further investigations regarding the significance of Her2 non-amplified tumors showing Her2 immunoreactivity and the definition of Her2 status in gastric cancers. Moreover, the correlation of Her2 expression with the expression of Her2 chaperoning HSP90 may indicate a synergistic regulation. Targeting HSP90 with or without Her2 may offer additional therapeutic options for gastric carcinoma treatment.