Lack of prognostic implications of HER-2/neu abnormalities in 345 stage I non-small cell carcinomas (NSCLC) and 207 stage I-III neuroendocrine tumours (NET) of the lung

HER-2/neu oncogene activation by either gene amplification and/or protein overexpression has been documented in several human malignancies. Irrespective of protein overexpression, HER-2/neu gene amplification is rare in lung cancer and studies on its prevalence and clinicopathological implications in early stage non-small cell lung cancer (NCSLC) and neuroendocrine tumours (NET) of the lung are lacking. We evaluated HER-2/neu abnormalities in 345 Stage I NSCLC and 207 Stage I-III NET of the lung of all the diverse histological types, by using immunohistochemistry and fluorescent in situ hybridization in selected cases. Overall, HER-2/neu immunoreactivity was detected in 23% of 345 NSCLC and in 7% of 207 NET. Gene amplification was seen in only 7 (7.4%) of the immunoreactive tumours, with high-level amplification (HER-2/neu gene to chromosome 17 ratio > 4.0) in 3 adenocarcinomas, 1 squamous-cell carcinoma and 1 large-cell neuroendocrine carcinoma (LCNEC), and low-level amplification (HER-2/neu gene to chromosome 17 ratio from 2.0 to 4.0) in 1 squamous-cell carcinoma and 1 LCNEC. None of tested carcinoids and SCLC showed gene amplification. All but 1 gene amplified case exhibited 2+ or 3+ membrane labeling. No relationship was found between gene amplification or protein overexpression and patients' survival or other clinicopathological variables. HER-2/neu gene amplification and protein overexpression are not closely correlated in lung carcinomas and do not bear any prognostic implication. Among neuroendocrine tumours, LCNEC show a slightly higher prevalence of either HER-2/neu gene amplification or protein overexpression.     

Reproducible Immunohistochemical Criteria Based on Multiple Raters’ Judgments for Expression of Thymidine Phosphorylase in Breast Cancer Tissue

The role of HER-2/ neu in male breast cancer is not well defined. The purpose of the current study was to measure the frequency of HER-2/ neu expression in primary male breast cancer, to demonstrate HER-2/ neu gene amplification in cases found to be positive for protein overexpression, and to correlate HER-2/ neu positivity with clinicopathological variables. Formalin-fixed, paraffin-embedded archival material from 99 primary male breast carcinomas was evaluated by immunohistochemistry (IHC) using the HercepTest (DAKO Corp., Hamburg, Germany). Scoring was performed according to established guidelines. All cases demonstrating HER-2/ neu staining by IHC (1+/2+ and 3+) were analyzed for HER-2/ neu gene amplification by fluorescence in situ hybridization (FISH) utilizing the PathVysion assay (Vysis Corp., Downers Grove, Illinois) to assess HER-2/ neu amplification status. The immunohistochemical staining of the HER-2/ neu protein revealed HER-2/ neu positivity in 15/99 (15.1%) cases, eight tumors showed 2+ and 7 tumors 3+ staining. HER-2/ neu gene amplification was observed in 11/99 cases (11,1%), and all of the 3+ and 4/8 from the 2+ cases were amplified. HER-2/ neu gene amplification/protein overexpression did not correlate with tumor state, histological grade or estrogen/progesterone receptor status nor the axillary lymph node status. This is the first comprehensive study of HER-2/ neu gene amplification by FISH analysis in primary male breast cancer. Compared to female primary breast cancer the percentage of HER-2/ neu positivity in our study was lower. Our data provide first evidence for HER-2/ neu gene amplification in male breast cancer. Further studies should be addressed on the potential application of the monoclonal rhuMAB HER-2/ neu antibody for treatment of HER-2/ neu positive male breast cancer.     

Determination of HER-2/neu amplification and expression in tumor tissue and cultured cells using a simple, phenol free method for nucleic acid isolation.

A rapid, simple and non-toxic procedure for the simultaneous isolation of DNA and RNA from tumor tissue and cells grown in vitro is described. Guanidinium isothiocyanate was used for homogenization of tumor tissue and for cell lysis. Separation of proteins, DNA and RNA was carried out by isopycnic centrifugation in cesium trifluoroacetate. DNA was further purified by salting out residual protein. Nucleic acids prepared by this method from 47 primary human carcinomas and 17 human cell lines were analysed for amplification and expression of the HER-2/neu proto-oncogene. 2- to 10-fold amplification of HER-2/neu was noted in 7/22 mammary carcinomas (32%) and in 4/14 ovarian carcinomas (28%). No amplification of the proto-oncogene was found in 4 laryngeal carcinomas, 1 pharyngeal carcinoma, 2 retrolingual carcinomas, 3 gastric carcinomas and 1 kidney carcinoma. HER-2/neu overexpression was observed in 6/22 of mammary carcinomas (27%) and 7/14 of ovarian carcinomas (50%). No overexpression was found in all other carcinomas studied. Concordance between amplification and overexpression was noted in 3 mammary and 4 ovarian carcinomas, respectively. 3 mammary and 3 ovarian carcinomas showed overexpression without amplification. 5 human mammary carcinoma cell lines showed both amplification and overexpression of HER-2/neu. In two mammary carcinoma cell lines (MDA MB-453 and ZR 75-1) overexpression was noted without amplification of the proto-oncogene. These data combine to suggest that mechanisms other than gene amplification may also lead to overexpression of the HER-2/neu protooncogene in cancer cells.     

No Strong Association Between HER-2/neu Protein Overexpression and Gene Amplification in High-grade Invasive Urothelial Carcinomas

The generation of urothelial carcinoma is caused by the accumulation of various molecular changes, as in most malignancies. There are conflicting data about the status of HER-2/neu oncogene in urothelial carcinomas. The aim of this study was to determine the status of HER-2/neu oncogene in high-grade invasive urothelial carcinoma of urinary bladder both in protein and DNA level. We evaluated HER-2/neu protein overexpression by immunohistochemistry (IHC) and gene amplification by fluorescent in situ hybridization (FISH) and real-time quantitative PCR in paraffin-embedded samples of high-grade invasive urothelial carcinoma obtained from 36 patients. Polysomy 17 was also assessed by FISH. Immunohistochemically, HER-2/neu protein overexpression was observed in 22 (61.1%) tumors (ten tumors with score 3+ and 12 with score 2+). Fourteen of 36 tumors (38.9%) were evaluated as negative (score 0 or 1+). Complete concordance between FISH and the PCR was seen in all of the samples scored as 0 and 1+ by IHC. HER-2/neu gene amplification was observed in three of 27 (11.1%) tumors by FISH (nine samples were non-informative) and in eight of 36 (22.2%) tumors by the PCR. The complete concordance between HER2-2/neu protein overexpression and gene amplification was seen only in three of 27 tumors. Polysomy 17 was seen in nine tumors (33.3%). The results indicated that, in contrast to breast cancer, there was no strong association between HER-2/neu overexpression and gene amplification in invasive urothelial carcinomas, and polysomy 17 was higher in tumors showing HER-2/neu overexpression.     

Detection of HER-2/neu (c-erb B-2) DNA amplification in primary breast carcinoma. Interobserver reproducibility and correlation with immunohistochemical HER-2 overexpression.

BACKGROUND: Fluorescent in situ hybridization (FISH) has been shown to be one of the most reliable methods with which to estimate the status of the HER-2/neu (or c-erb B-2) oncogene at the DNA level. METHODS: To study interobserver reproducibility and to determine more clinically correlated criteria for HER-2/neu alterations, two observers independently estimated HER-2/neu DNA status. The correlation between the consensus HER-2/neu DNA status by FISH and HER-2/neu protein status detected by immunohistochemistry (IHC) using a polyclonal antibody was studied in 216 surgically resected breast carcinomas and 34 noncancerous tissues. RESULTS: According to the HER-2/CEP17 ratio and mean HER-2 copies per nucleus, agreement level of HER-2/neu amplification was shown to be nearly perfect between two observers (kappa statistic (kappa) = 0.94 and kappa = 0.84). Finally, 40 tumors (19%) were judged to have HER-2/neu DNA amplification, with 6 having low-level amplification (> or = 2 but < 3 folds) and 34 having high-level amplification (> or = 3 folds). One hundred seventy-six other tumors, including 3 tumors that only 1 of the observers determined to be low-level amplifiers, and 34 noncancerous tissues had no detected amplification. The DNA amplification status was concordant between invasive and intraductal components in 14 carcinomas. HER-2/neu protein overexpression of moderate (2+) or high (3+) intensity based on IHC was detected in 51 carcinomas (24%), and was 2+ in 20 carcinomas and 3+ in 31 carcinomas. The HER-2/CEP17 ratio of > or = 2 was concordant with IHC findings of 2+/3+ in 91% of carcinomas (195 of 215 carcinomas), with a sensitivity of 70% (35 of 50 carcinomas) and a specificity of 97% (160 of 165 carcinomas). High-level amplification was detected in 29 of 31 IHC 3+ cases (94%), but in only 5 of 20 IHC 2+ cases (25%) and 0 in 165 IHC 0/1+ cases. All 34 cases with high-level amplification showed an IHC score of 3+ (29 cases) or an IHC score of 2+ (5 cases), but only 1 case was found to have an IHC score of 3+ and the remainder were IHC 0/1+ in 6 low-amplification cases. The concordance rate of the high-level amplification with an IHC score of 3+ was 97% (208 of 215 cases), with a sensitivity of 94% (29 of 31 cases) and a specificity of 97% (179 of 184 cases). CONCLUSIONS: The results of the current study indicated that high-level HER-2/neu amplification and an IHC score of 3+ nearly optimally identified breast carcinomas with clinically and biologically significant HER-2/neu activation. Conversely, it was confirmed that careful interpretation of test results is required in the case of low-level amplification and/or an IHC score of 2+.     

食管癌组织中HER-2/neu蛋白表达和基因扩增的检测及其临床意义

目的:检测食管癌组织中HER-2/neu蛋白表达及其基因扩增情况,并探讨其与食管癌患者临床病理指标的关系。方法:回顾性分析2000～2006年武汉大学人民医院收治的167例食管癌患者的临床资料。采用免疫组织化学和荧光原位杂交方法检测167例食管癌患者癌组织中HER-2/neu蛋白表达及基因扩增情况。结果:食管癌组织中HER-2/neu蛋白表达水平与基因扩增存在一定相关性(P<0.05),HER-2/neu蛋白的表达与食管癌分化程度和临床分期有关系(P<0.05),而HER-2/neu基因扩增仅与食管癌临床分期有关系(p<0.05)。HER-2/neu蛋白过表达和基因扩增阳性均可缩短食管癌患者的生存期(P<0.05)。结论:HER-2/neu蛋白过表达及基因扩增可能是食管癌患者的一个预后指标,联合检测HER-2/neu蛋白表达水平及基因扩增程度对于食管癌的靶向治疗可能具有一定指导意义。     

Long-term prognostic significance of HER-2/neu in untreated node-negative breast cancer depends on the method of testing

IntroductionThe prognostic significance of HER-2/neu in breast cancer is a matter of controversy. We have performed a study in 101 node-negative breast cancer patients with long-term follow-up not treated in the adjuvant setting, and analysed the prognostic significance of immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH), both separately and in combination, in comparison with traditional prognostic factors.MethodsOverexpression was classified semiquantitatively according to a score (0 to 3+) (HER-2_SCO). FISH was used to analyse HER2/neu amplification (HER-2_AMP). Patients classified 2+ by IHC were examined with FISH for amplification (HER-2_ALG). Patients with 3+ overexpression as well as amplification of HER-2/neu were positive for the combined variable HER2_COM. These variables were compared with tumour size, histological grade and hormone receptor status.ResultsHER-2_SCO was 3+ in 20% of all tumours. HER-2_ALG was positive in 22% and amplification (HER-2_AMP) was found in 17% of all tumours. Eleven percent of the tumours showed simultaneous 3+ overexpression and amplification. Only histological grade (relative risk [RR] 3.22, 95% confidence interval [CI] 1.73–5.99, P = 0.0002) and HER-2_AMP (RR 2.47, 95% CI 1.12–5.48, P = 0.026) were significant for disease-free survival in multivariate analysis. For overall survival, both histological grade (RR 3.89, 95% CI 1.77–8.55, P = 0.0007) and HER-2_AMP (RR 3.08, 95% CI 1.24–7.66, P = 0.016) retained their independent significance.ConclusionThe prognostic significance of HER-2/neu in node-negative breast cancer depends on the method of testing: only the amplification of HER-2/neu is an independent prognostic factor for the long-term prognosis of untreated node-negative breast cancer.     

HER-2 gene amplification by fluorescence in situ hybridization (FISH) compared with immunohistochemistry (IHC) in breast cancer: a study of 528 equivocal cases

The concordance rate between fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) on evaluating HER-2/neu status is still controversial, especially for the IHC 2+/equivocal cases. In this study, we investigated the amplification of HER-2/neu gene by FISH in IHC (2+)/equivocal specimens to clarify the correlation between HER-2/neu and clinicopathologic features of breast cancers. HER-2/neu amplification was determined by FISH on 528 specimens of breast carcinomas with equivocal expression of HER-2/neu protein by IHC detection. 65.5 % of IHC 2+ patients were negative for HER-2/neu amplification, 29.0 % were positive and the remaining was equivocal. A statistically significant inverse association was found between hormone receptor expression and HER-2/neu amplification (P < 0.05). Furthermore, polysomy of CEP17 was detected in 60 % of breast carcinomas. The results highlight the necessity of FISH test for further categorization when breast carcinoma cases are scored 2+ by IHC.     

HER-2/neu（2+）腔面型乳腺癌的HER-2基因扩增与TopⅡα蛋白及临床特征的关联性分析

目的：分析HER-2基因扩增与腔面型HER-2/neu（2+）乳腺浸润性导管癌的临床病理特征及TopⅡα蛋白的关系。方法运用FISH检测手段对68例雌激素受体（ER）/孕激素受体（PR）阳性的腔面型HER-2/neu（2+）乳腺浸润性导管癌标本进行检测;应用免疫组化法（IHC）对68例标本进行TopⅡα蛋白表达检测。结果 FISH检测结果显示,68例标本中,HER-2基因扩增为13例（19.1%）;HER-2基因扩增在不同年龄、术后病理分期、淋巴结转移数目、Ki-67表达的患者之间差异无统计学意义;HER-2基因扩增病例中,TopⅡαⅠ级6例（46.2%）,Ⅱ级6例（46.2%）,Ⅲ级1例（7.7%）,Ⅳ级0例。TopⅡα蛋白表达情况在有无HER-2基因扩增的乳腺癌间差异无统计学意义（Z=1.353,P=0.176）。结论在HER-2/neu（2+）腔面型乳腺癌中,HER-2基因扩增与年龄、术后病理分期、淋巴结转移数目、Ki-67表达和TopⅡα蛋白表达无关。     

Her-2/neu analysis in archival tissue samples of human breast cancer: comparison of immunohistochemistry and fluorescence in situ hybridization.

PURPOSE: The objective of our study was to compare the methods used in the literature to analyze HER-2/neu status on archival breast cancer tissue. Therefore, a series of antibodies was evaluated to assess their immunohistochemical (IHC) sensitivity in correlation to gene amplification determined by fluorescence in situ hybridization (FISH). MATERIALS AND METHODS: HER-2/neu overexpression was studied on paraffin sections of 85 invasive breast cancers using a panel of five monoclonal (9G6, 3B5, CB11, TAB250, GSF-HER2) and two polyclonal antibodies (A8010, A0485) in addition to the HercepTest (DAKO, Glostrup, Denmark). HER-2/neu gene amplification was determined by FISH using a dual-color probe (PathVysion; Vysis, Stuttgart-Fasanenhof, Germany). RESULTS: HER-2/neu overexpression was demonstrated in 26% (9G6, TAB250, GSF-HER2), 27% (3B5, CB11), 33% (A8010) and 42% (A0485, HercepTest) of the tumors. FISH on paraffin sections identified gene amplification in 28% of the tumors. Strongly positive IHC results (3+) were always associated with gene amplification. Among the 16 tumors presented with weakly positive IHC results (2+) using the HercepTest, 12 (75%) lacked gene amplification. CONCLUSION: The comparison of IHC and FISH demonstrated an excellent correlation of high-level HER-2/neu overexpression (3+) with gene amplification; ie, FISH does not provide further information in these tumors. However, weakly positive IHC results (2+) obtained with the HercepTest share only a minor association with gene amplification.     

Clinical evaluation of HER-2/neu protein in malignant pleural effusion-associated lung adenocarcinoma and as a tumor marker in pleural effusion diagnosis.

PURPOSE: Lung adenocarcinoma presenting as malignant pleural effusion (MPE) is common in Taiwan. Microscopically, the involved pleurae are infiltrated by numerous tumor foci, which suggests that the cancer cells are highly invasive. Overexpression of HER-2/neu has been related to proliferation, antiapoptosis, and the high invasiveness of various cancer cells. We therefore were interested in studying the role of HER-2/neu in MPE-associated adenocarcinoma cell lung cancer (ADCLC). Experimental Design: The expression of HER-2/neu in pleural effusion was measured by ELISA. The HER-2/neu protein expression on tumor cells was evaluated by immunohistochemical (IHC) staining, and gene amplification was assayed by fluorescence in situ hybridization. RESULTS: The mean value of HER-2/neu in pleural effusions of patients with ADCLC and other nonmalignant lung diseases was 9.9 and 2.7 ng/ml, respectively. The difference is statistically significant (P < 0.001). Compared with cytokeratin 19 fragment CYFRA 21-1, the performance of HER-2/neu as a tumor marker in pleural effusion diagnosis was better. Overexpression of HER-2/neu in tumor tissues was found in 70% (23 of 32) of patients with MPE-associated ADCLC, 30% (13 of 43) with stage I/II non-small cell lung cancer (NSCLC), and 44% (14 of 32) with stage III NSCLC. The incidence of HER-2/neu overexpression in tumor tissues of patients with MPE-associated ADCLC was significantly higher than that of patients with stage I-III NSCLC without MPE. HER-2/neu gene amplification was uncommon (1.9%). The correlation between the IHC H-score in tumor samples and the pleural effusion level of HER-2/neu was significant (P < 0.01). A higher incidence of HER-2/neu expression beyond the cutoff point (5.5 ng/ml) in pleural effusions was also found in patients whose IHC H-scores were >50. CONCLUSIONS: These findings indicate that HER-2/neu is important in the pathogenesis of MPE-associated ADCLC and is a potential tumor marker for a diagnosis of pleural effusion.     

Frequencies of HER-2/neu expression and gene amplification in patients with oesophageal squamous cell carcinoma

The utilisation of antitumour T cells induced by cancer vaccination with HER-2 peptides or antibodies (Herceptin) against HER-2, as immunotherapy for oesophageal cancer, is a novel and attractive approach. It is important to clarify the frequencies of HER-2 expression and gene amplification in patients with oesophageal squamous cell carcinoma (SCC) and to evaluate the relationship between HER-2 status and HLA haplotype, since the candidates for HER-2 peptide-based vaccination are restricted to a certain HLA haplotype. We determined the frequency of HER-2 expression using the HercepTest for immunohistochemistry and HER-2 gene amplification by fluorescence in situ hybridisation (FISH) assay in oesophageal SCC (n=66). HER-2-positive tumours (1+/2+/3+) analysed by a HercepTest were observed in 30.3% of all the patients and HER-2 gene amplification evaluated by FISH was observed in 11.0% of all the patients, in which all HercepTest (3+) tumours were found to have gene amplification and three of six moderately positive (2+) tumours showed gene amplification. Furthermore, HER-2-positive cells were present more diffusely and were larger within each tumour in the patients who were HercepTest 3+ than those who were HercepTest 1+. Moreover, the survival rate in HER-2-positive group was significantly worse than that in HER-2-negative group. Also, the survival rate in the patients with HER-2 gene amplification was significantly worse than that without HER-2 gene amplification. In addition, oesophageal SCC patients with both HLA-A24-positive and HER-2-positive tumours (1+/2+/3+) accounted for 26% of these cases, and both HLA-A2- and HER-2-positive tumours accounted for 18% of them.     

Analysis of aneusomy level and HER-2 gene copy number and their effect on amplification rate in breast cancer specimens read as 2+ in immunohistochemical analysis

Our aim was to determine the aneusomy level and the HER-2 gene copy numbers, by fluorescence in situ hybridization (FISH) and to analyze their impact on the amplification rate in breast carcinomas considered HER-2 weakly positive cases by immunohistochemistry. We evaluated 343 breast carcinomas using double colour FISH (LSI Her-2/neu gene and CEP 17). Monosomy and polysomy were demonstrated in 24.2% and 46.1% respectively and 101/343 (29.6%) of the specimens were amplified by FISH. A statistically significant difference was observed, when we compared the amplification percentage in polysomic and monosomic specimens (P<0.0001) and, among polysomic specimens, when tumours were compared with HER-2 gene signals number per cell between 3 and 10 and >10 respectively (P<0.0001). Logistic regression analysis showed that HER-2 signals >10 and polysomy absence were independently associated with amplification. Our results confirm that the majority of 2+ IHC cases express the HER-2 protein without gene amplification and highlight the effect of chromosome 17 aneusomy and the HER-2 gene copy number on amplification.     

Characterization of the HER-2/neu oncogene by immunohistochemical and fluorescence in situ hybridization analysis in oral and oropharyngeal squamous cell carcinoma.

PURPOSE: The role of HER-2/neu in squamous cell carcinoma (SCC) of the head and neck is not well defined. The purpose of the current study is to measure the frequency of HER-2/neu expression, to demonstrate HER-2/neu gene amplification in the cases found to be positive for protein overexpression, and to investigate the prognostic significance of overexpression and/or amplification in SCC of the head and neck. EXPERIMENTAL DESIGN: A cohort of 77 patients with SCC of the oral cavity or oropharynx, with stage III or IV disease and uniformly treated with surgical resection and postoperative radiation, served as the primary patient population for the study. Of these, 56 patients had adequate follow-up and paraffin-embedded specimens available for analysis. Median follow-up was 6.1 years. Each of the paraffin-embedded specimens were immunohistochemically stained for HER-2/neu expression and graded for intensity of staining by a pathologist. All cases that demonstrated positive staining by immunohistochemistry were analyzed by fluorescence in situ hybridization (FISH) to assess HER-2/neu amplification status. RESULTS: Five-year survival for the 56 evaluable patients was 40%, with 25% experiencing local relapse, 18% regional relapse, and 25% distant relapse. The percentage of tumors staining positive for HER-2/neu by immunohistochemistry was 17%. There was no statistically significant correlation between HER-2/neu and T stage, N stage, tumor grade, survival, or disease-free survival. HER-2/neu expression did correlate with vascular endothelial growth factor expression. FISH analysis revealed four cases that were amplified for HER-2/neu. Of note, of the 4 amplified cases, 2 suffered regional relapse, 1 suffered distant metastasis, and all 4 expired by 5 years of follow-up. CONCLUSIONS: This is the first demonstration of HER-2/neu gene amplification by FISH in SCC of the head and neck. FISH validates a previously contested controversial role for HER-2/neu gene overexpression in SCC of the head and neck. The prognostic significance and clinical implications of HER-2/neu expression and amplification in head and neck cancer will require additional studies.     

Oncogene HER-2 in Canine Mammary Gland Carcinomas

Immunohistochemical (IHC) HER-2/neu protein overexpression was found in 17.6% of canine mammary gland carcinomas, a percentage similar to that observed in human breast carcinoma, but there was no gene amplification by chromogenic in situ hybridization (CISH). Canine mammary carcinoma would be a suitable natural model of that subset of human breast carcinomas with HER-2 protein overexpression without gene amplification.     

AKT2 is frequently upregulated in HER-2/neu-positive breast cancers and may contribute to tumor aggressiveness by enhancing cell survival

Amplification or overexpression of the HER-2/neu gene in breast cancers is associated with aggressive behavior and resistance to therapeutic regimens. The molecular mechanisms that contribute to therapeutic resistance/survival of HER-2/neu-overexpressing tumor cells have not been well defined. To determine if phosphatidylinositol 3-kinase/AKT signaling contributes to cell survival in HER-2/neu-positive breast cancers, we performed immunohistochemical analyses to evaluate expression of HER-2/neu and AKT in a series of 52 breast carcinomas. Elevated expression of HER-2/neu was found to correlate with overexpression of AKT2 protein and activation of AKT kinase. HER-2/neu-overexpressing breast cancer cell lines were resistant to apoptosis induced by UV treatment and hypoxia, which was suppressed in the presence of the phosphatidylinositol 3-kinase inhibitors LY294002 and wortmannin, indicating a link between AKT activation and stress resistance in HER-2/neu-overexpressing cells. These observations suggest that AKT signaling augments resistance to stress-induced apoptosis in breast cancer cells overexpressing HER-2/neu.     

Molecular-cytogenetic analysis of HER-2/neu gene in BRCA1-associated breast cancers

The BRCA1 tumor suppressor gene and the HER-2/neu oncogene are located in close proximity on the long arm of chromosome 17 (17q11-21). Absence of BRCA1 or functional overexpression of the HER-2/neu gene presumably contributes to the somatic phenotype of breast cancer in premenopausal women, characterized by unfavorable prognostic features such as high tumor grade, hormone receptor negativity, and high proliferation rate. To examine whether amplification of HER-2/neu contributes to the aggressive biology of BRCA1-associated tumors, we have performed fluorescence in situ hybridization on formalin-fixed paraffin-embedded breast tumor tissue sections from 53 BRCA1 mutation carriers and 41 randomly selected, age-matched sporadic breast cancer cases. Although BRCA1-associated and sporadic tumors were equally likely (19% versus 22%) to exhibit HER-2/neu amplification [defined as a ratio of HER-2/neu copies to chromosome 17 centromere (CEP17) copies > or = 2], 6 (15%) of the sporadic tumors were highly amplified (defined as a ratio greater-than-or-equal 5) versus none of the BRCA1-associated tumors (P = 0.048). HER-2 protein overexpression as measured by immunohistochemical analysis was not observed among the BRCA1-associated cases (P = 0.042). Four of 21 (19%) sporadic tumors exhibited strong membranous staining of HER-2 (intensity level of 3+) as compared with 0 of 39 BRCA1-associated tumors. Our data suggest that a germ-line mutation in the BRCA1 tumor suppressor gene is associated with a significantly lower level of HER-2/neu amplification. Thus, it is possible that BRCA1-associated and HER-2/neu-highly amplified tumors progress through distinct molecular pathways, and the aggressive pathological features of BRCA1-associated tumors appear unrelated to amplification of the adjacent HER-2/neu oncogene.     

Quantification of Her-2/Neu Gene in Breast Cancer Patientsusing Real Time-Polymerase Chain Reaction (Q-PCR) andCorrelation with Immunohistochemistry Findings

Background: HER-2/neu is a proto-oncogene that encodes a transmembrane tyrosine kinase growth factorwhich is crucial for stimulating growth and cellular motility. Overexpression of HER-2/neu is observed in 10-35%of human breast cancers and is associated with pathogenesis, prognosis as well as response to therapy. Giventhe imperative role of HER-2/neu overexpression in breast cancer, it is important to determine the magnitudeof amplification which may facilitate a better prognosis as well as personalized therapy in affected patients. Inthis study, we determined HER-2/neu protein expression by immunohistochemistry (IHC) concurrently withHER-2/neu DNA amplification by quantitative real time-polymerase chain reaction (Q-PCR). Materials andMethods: A total of 53 paired tissue samples from breast cancer patients were frozen-sectioned to characterizethe tumour and normal tissues. Only tissues with 80% tumour cells were used in this study. For confirmation,Q-PCR was used to determine the HER-2/neu DNA amplification. Results: We found 20/53 (37.7%) of thetumour tissues to be positive for HER-2/neu protein overexpression using IHC. Out of these twenty, only 9/53(17%) cases were in agreement with the Q-PCR results. The concordance rate between IHC and Q-PCR was79.3%. Approximately 20.7% of positive IHC cases showed no HER-2/neu gene amplification using Q-PCR.Conclusion: In conclusion, IHC can be used as an initial screening method for detection of the HER-2/neu proteinoverexpression. Techniques such as Q-PCR should be employed to verify the IHC results for uncertain cases aswell as determination of HER-2/neu gene amplification     

HER2/neu gene amplification and protein overexpression in G3 pT2 transitional cell carcinoma of the bladder: a role for anti-HER2 therapy?

HER2/neu is an oncogene encoding a type 1 tyrosine kinase growth factor receptor. Polysomy 17, gene amplification and HER2/neu protein overexpression are associated with a poor prognosis in transitional cell carcinomas (TCC) of the bladder. Due to the application of different laboratory techniques, the exact incidence of HER/neu abnormalities remains uncertain in TCC. Standardised laboratory techniques are therefore important in the determination of the HER2/neu status if an assessment of the potential value of anti-HER2/neu treatments in the clinical management of patients with TCC is to be made. In this study, 75 TCCs with evidence of detrusor muscle invasion at first clinical presentation were included. Gene amplification, polysomy 17 and HER2 copy number were assessed using fluorescence in situ hybridisation (FISH), with separate probes for chromosome 17 and HER2/neu. Protein overexpression was assessed using immunohistochemistry (IHC), with the CB11 antibody and a scoring system evaluating only membranous staining as positive. The mean patient age was 69.5 years (range 42-93 years) and the median survival was 15 months (range 1-156 months). Polysomy 17 occurred in 97%, increased HER/neu copy number in 92% and HER2/neu gene amplification in 7%. Protein overexpression occurred in 57% of cases. Polysomy 17 and HER2/neu protein overexpression are common in G3 pT2 TCCs of the bladder. However, gene amplification is uncommon. Mechanisms other than gene amplification may be responsible for protein overexpression in this tumour type. Evidence from breast cancer suggests that only tumours with HER2/neu gene amplification respond to the anti-HER2/neu therapy trastuzumab (Herceptin). If this were true for bladder cancer, only 4/75 (5%) of G3 pT2 TCCs would be suitable for treatment. The role of trastuzumab in these tumours remains untested at present.     

Gene amplification and protein overexpression of HER-2/neu in human extrahepatic cholangiocarcinoma as detected by chromogenic in situ hybridization and immunohistochemistry: its prognostic implication in node-positive patients.

BACKGROUND: In cholangiocarcinoma (CC), HER-2/neu protein overexpression has rarely been reported and the results are conflicting. The present study aimed to clarify the rates of HER-2/neu protein overexpression and gene amplification in human extrahepatic CC and to evaluate the correlation between HER-2/neu and several clinicopathologic features. PATIENTS AND METHODS: We investigated HER-2 gene amplification by chromogenic in situ hybridization (CISH) and HER-2/neu protein overexpression by immunohistochemistry in 55 extrahepatic CC patients who underwent curative surgery at our institution. RESULTS: Overexpression of HER-2/neu protein (staining intensity score > or = 2) was found in 16 out of 55 patients (29.1%). CISH revealed that HER-2 gene signals were increased in 10 out of 55 patients (18.1%). There was a positive and significant correlation between HER-2 gene amplification and HER-2/neu protein overexpression (Spearman's rho = 0.718, P < 0.01). In subgroup with lymph node metastases, HER-2 gene amplification by CISH was significant prognostic factor for survival (OR 43.6, 95% confidence interval 1.6-1219.6). CONCLUSIONS: HER-2/neu protein overexpression by HER-2 gene amplification may occur in human extrahepatic CC and constitute an independent prognostic factor in patients with lymph node metastases. In subgroup with lymph node metastases who exhibit HER-2/neu overexpression might constitute potential candidates for new adjuvant therapy, such as humanized monoclonal antibodies.