Impact of HER-2 Overexpression/Amplification on the Prognosis of Gastric Cancer Patients Undergoing Resection: A Single-Center Study of 1,036 Patients

Department of Surgery, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan.
The Oncologist (Impact Factor: 4.87). 12/2011; 16(12):1706-13. DOI: 10.1634/theoncologist.2011-0199
Source: PubMed


Opinions regarding the impact of human epidermal growth factor receptor (HER)-2 overexpression or HER-2 amplification on the prognosis of gastric cancer patients are mixed. The present study attempted to clarify this issue by investigating a large cohort of surgical patients.
We investigated 1,036 gastric cancer patients undergoing curative-intent resection. Their surgical specimens were evaluated for HER-2 expression by immunohistochemistry (IHC), and those with HER-2 expression levels of 2+ were additionally subjected to fluorescence in situ hybridization (FISH). Data on demographic and clinicopathological features and relevant prognostic factors in these patients were analyzed.
HER-2 positivity was noted in 64 (6.1%) of 1,036 gastric cancer patients, including 46 patients whose HER-2 expression level was 3+ on IHC and 18 patients whose FISH results were positive. On univariate analysis, HER-2 positivity was more often associated with differentiated histology, intestinal type, and negative resection margins, whereas only differentiated histology was independently associated with HER-2 positivity in a logistic regression model. For stage I-IV gastric cancer, HER-2 was not a prognostic factor. In a subpopulation study, although HER-2 positivity emerged as a favorable prognostic factor for stage III-IV gastric cancer on univariate analysis, it failed to be an independent prognostic factor after multivariate adjustment.
The prevalence of HER-2 positivity, determined using standardized assays and scoring criteria in a large cohort of gastric cancer patients after resection, was 6.1%. HER-2 positivity was phenotypically associated with differentiated histology. HER-2 is not an independent prognostic factor for gastric cancer.

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Available from: Jun-Te Hsu
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    • "In our study, the rate of HER-2/neu overexpression/amplification was 11.89%, which fell within the range of 9.3% to 22.6% [12,13,15,18,21-23] reported after 2005 using the old scoring system. It was also in the range of 6% to 12% given by Hsu et al. using the new scoring system [24]; these authors were the first to use the new scoring system in a large-scale experiment, with a reported rate of 6.1% for HER-2/neu overexpression. The authors attributed their observed low positivity to the new criteria and some other reasons, such as geographic variations, tumor heterogeneity, the employment of different antibodies, and inter-observer variation. "
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    ABSTRACT: 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.
    Full-text · Article · Dec 2012 · World Journal of Surgical Oncology
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    • "This percentage value may be influenced by the heterogeneity [11] of HER2 expression in large gastric cancer, so that the assessment of HER2 in just 1 tissue block obtained from surgical specimens of gastrectomy could produce false-negative results. For example, Hsu et al [6] studying HER2 expression in a large case series of gastric resection for cancer showed a rate of positive cases of 6.1%. This low rate of HER2 expression failed to be an independent prognostic factor at multivariate analysis. "
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    ABSTRACT: Gastric cancer shows intratumoral heterogeneity for human epidermal growth factor receptor 2 expression. We evaluated whether the number of tissue blocks analyzed or the antibodies used may influence the immunohistochemical results in gastrectomy specimens. Clinicopathologic data from 148 patients receiving gastric surgery for cancer were collected. One tissue block for each of 88 primary tumors and 60 paired primary tumors and metastases was examined for human epidermal growth factor receptor 2 status by immunohistochemistry using 3 different antibodies (HercepTest, CB11, and 4B5) and by fluorescent in situ hybridization. Two additional tissue blocks of the primary tumor were tested by immunohistochemistry if the results were negative on the first tissue block. The concordance among the 3 antibodies was 94.5% (testing 1 tissue block). Two cases showed a clinically significant discrepancy between primary tumor (score 0) and lymph nodes metastases (score 3+). Additional block analysis increased both the sensitivity (from 63% to 83%) and the accuracy (from 91% to 94%) of immunohistochemistry as compared with fluorescent in situ hybridization. The multiblock approach could potentially identify a greater number of human epidermal growth factor receptor 2-positive gastric cancers, particularly those with higher levels of intratumor heterogeneity. In turn, human epidermal growth factor receptor 2 positivity correlated with a worse prognosis (P = .011) and was an independent variable in multivariate analysis (hazard ratio, 1.57). In conclusion, testing more than 1 tissue block of cancer from specimens of gastric resection provides a more reliable human epidermal growth factor receptor 2 assessment regardless of the antibody used.
    Full-text · Article · Jun 2012 · Human pathology
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    ABSTRACT: The human epidermal receptor-2 (HER-2) is amplified in up to 25% of patients with gastroesophageal adenocarcinomas. Although the presence of this amplification does not appear to confer a poor prognosis, it provides a valuable novel therapeutic target for this group of patients. Trastuzumab is a fully humanized monoclonal antibody directed at HER-2 which binds the external domain of the receptor and exerts its action via a combination of antibody-dependent cytotoxicity, reduced shedding of the extracellular domain, inhibition of dimerization and possibly receptor downregulation. The ToGA trial was an international multicentre randomized phase III study which evaluated the addition of trastuzumab to a cisplatin plus fluoropyrimidine chemotherapy doublet in 594 patients with HER-2-positive advanced gastric or oesophagogastric junction adenocarcinoma. The combination of the antibody with chemotherapy significantly improved response rate, median progression-free survival and median overall survival without additional toxicity or adversely affecting quality of life. Accordingly, trastuzumab plus chemotherapy is now a standard first-line treatment option for patients with advanced HER-2-positive gastroesophageal cancer. Unfortunately, many patients with HER-2-positive cancer exhibit primary resistance to trastuzumab and the remainder will acquire resistance to the antibody; therefore, urgent investigation into novel agents which may circumvent resistance mechanisms is warranted. Small molecule inhibitors of HER-2, which commonly also target other members of the HER family of receptors, such as EGFR and HER-3, are currently undergoing evaluation in gastroesophageal cancer as first-line alternatives to trastuzumab and second-line salvage treatments for trastuzumab-resistant disease. Extrapolating the successful use of trastuzumab in the advanced disease setting, clinical trials are underway to assess the role of this antibody in the perioperative and adjuvant settings, where it is hoped that it will have a meaningful impact upon the currently poor survival rates.
    Full-text · Article · Sep 2012 · Therapeutic Advances in Gastroenterology
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