HER-2/neu oncogene amplification by fluorescence in situ hybridization in epithelial tumors of the ovary

HER-2/neu gene amplification and protein overexpression have been associated with prognosis in breast, lung and prostate cancers but have not been extensively studied in ovarian carcinoma. For the study, we selected 5-micron-thick, formalin-fixed, paraffin-embedded tissue sections from 74 cases of ovarian epithelial tumors of low malignant potential and ovarian carcinoma. Tumors were graded and staged and evaluated for amplification of the HER-2/neu gene by fluorescence in situ hybridization. HER-2/neu amplifications was present in 3 of 13 serous, mucinous, and endometrioid epithelial tumors of low malignant potential and in 40 of 61 epithelial carcinomas. In the carcinoma group, amplification did not correlate with stage, grade, or tumor type. Mean follow-up was 31 months; 1 patient with a low malignant potential tumor and 32 patients with carcinomas died of disease. On univariate and multivariate analysis, survival correlated with stage of disease but not with HER-2/neu amplification. HER-2/neu amplification by fluorescence in situ hybridization can be performed on tissue sections of ovarian neoplasms; amplification is uncommon in ovarian tumors of low malignant potential, but is present in 66% of ovarian epithelial carcinomas. HER-2/neu amplification did not predict outcome in ovarian epithelial neoplasia but may have an important role in tumor development.     

HER-2 gene amplification in Paget disease of the nipple and extramammary site: a chromogenic in situ hybridization study.

Patients with human epidermal growth factor receptor 2 (HER-2) overexpressing breast carcinomas have a more aggressive clinical behavior and their tumors are often hormone receptor negative. However, the recently introduced anti-HER-2 antibody trastuzumab has been proven to improve the survival and controls the disease in a significant proportion of these patients. Therefore, the analysis of HER-2 in patients with breast cancer has become an important and routine test to select those who may benefit from the gene-based targeted therapy trastuzumab (herceptin). There is good correlation between HER-2/neu protein overexpression and HER-2 gene amplification in breast cancer. However, inconsistent results have been reported in the rate of HER-2/neu protein overexpression in other malignant neoplasms. Furthermore, only rare studies have investigated the correlation between the HER-2/neu protein overexpression and the status of HER-2 gene in these tumors. We investigated the HER-2 gene and protein status in several cases of Paget disease of the nipple and vulva by using a chromogenic in situ hybridization assay and immunohistochemistry. We find that the majority of the Paget disease of the breast demonstrate HER-2 gene amplification, whereas most of the extramammary Paget disease lack HER-2 gene amplification. In addition, our results show a good correlation between HER-2/neu protein overexpression and HER-2 gene amplification in Paget disease of the nipple, but we were unable to confirm this correlation in HER-2/neu protein overexpressing Paget disease of the vulva.     

Prognostic significance of p34cdc2 cyclin-dependent kinase and MIB1 overexpression, and HER-2/neu gene amplification detected by fluorescence in situ hybridization in breast cancer.

The HER-2/neu oncogene, localized to chromosome 17q, shares substantial homology with the epidermal growth factor receptor. HER-2/neu gene amplification and protein overexpression have been associated with poor prognosis in breast cancer. Formalin-fixed paraffin-embedded primary invasive breast cancer tissues from 135 women were tested for HER-2/neu gene amplification by automated fluorescence in situ hybridization (FISH) using a sequence probe. The tumors also were evaluated by immunohistochemistry for proliferation markers Ki 67 (MIB1) and p34cdc2 cyclin-dependent kinase. Patients were followed up for a mean of 61 months. There were 70 node-negative and 65 node-positive cases. Ki 67 and p34cdc2 proliferation marker overexpression, HER-2/neu oncogene amplification, large tumor size, high tumor grade, advanced tumor stage, positive lymph node status, and distant metastasis at the time of diagnosis predicted disease-related death in combined node-negative and node-positive breast cancer. HER-2/neu gene amplification, tumor stage, lymph node metastasis, tumor grade, and distant metastasis at the time of diagnosis independently predicted disease outcome. HER-2/neu amplification detected by FISH also predicted disease-related death independent of lymph node status, tumor grade, and distant metastasis in breast cancer patients who received adjuvant therapy.     

HER-2/neu gene amplification in ovarian tumours: a comprehensive immunohistochemical and FISH analysis on tissue microarrays

Aims : Data on HER-2/ neu overexpression, its correlation to prognosis and the success of treatment with Herceptin^® in ovarian carcinomas are scarce and contradictory. Therefore we assessed HER-2/ neu expression and amplification in a large series of ovarian tumours by using tissue microarrays (TMAs).
Methods and results : Two TMAs containing 173 invasive carcinomas, 36 borderline tumours, 20 granulosa cell tumours, 14 carcinosarcomas, 11 benign cystadenoms and eight other pelvic tumours were constructed to assess HER-2/ neu gene amplification by fluorescence in-situ hybridization (FISH) and immunohistochemistry. Immunohistochemistry was successful in 94.3%; 81.8% were HercepTest^TM negative, 11.3% were scored as 1+, 4.1% as 2+ and 2.8% as 3+, including 3.1% of invasive carcinomas, 2.8% of borderline tumours and 7.7% of carcinosarcomas; 83.6% could be analysed successfully by FISH revealing no aberration in 75.8%, low amplification in 2.7% and high amplification in 3.7% of the cases. In 17.8% monosomy, trisomy, polysomy or deletion could be detected. All cases with high-level amplification had 2+ or 3+ scores on immunohistochemistry.
Conclusions : TMA is a feasible tool to study a large number of ovarian cases. Correlation between immunohistochemistry and FISH was excellent. HER-2/ neu overexpression or gene amplification does not correlate with histological tumour type, stage, grade or prognosis.     

Bcl-2 in ovarian carcinoma: a clinicopathologic, immunohistochemical and molecular study

We investigated the immunohistochemical espression of bcl-2 and the genetic assessment of the bcl-2 gene in relation to responsiveness to first line chemotherapy and to the clinical outcome in advanced ovarian carcinoma patients. We have compared 17 patients, with FIGO stage III C, ovarian serous carcinomas, G3, living with no evident disease five years after primary surgical treatment; to 19 patients who had died of progression of disease no later than two years after primary surgical treatment. The correlation of bcl-2 expression with the survival and the clinical responsiveness to chemotherapy, were analysed with the logistic regression. We observed a bcl-2 expression in tumor cells in 25% of the cases. Molecular genetic analysis of the bcl-2 gene was performed for all the bcl-2 immunohistochimical positive cases. No traslocation t(14;18)(q32;q21) of the gene bcl-2 were found. The bcl-2 over-expression was found to be a significant independent predictor of responsiveness to chemotherapy (p = 0.04), but it was not correlated with the overall survival of the ovarian cancer patients. The prognostic value of bcl-2 espression may help in the management of ovarian cancer patients permitting the selection of more aggressive first line chemotherapy. In addition, the knowledge of the molecular mechanism, which is responsible of the over-expression of bcl-2, may help in the understanding of mechanisms responsible for chemoresistance. Further studies in this area will help clarify this therapeutic possibility.     

Fluorescence in situ hybridization and immunohistochemical assays for HER-2/neu status determination: application to node-negative breast cancer

BACKGROUND: HER-2/neu (ERBB2) gene amplification and/or overexpression is a major event in human breast tumorigenesis. HER-2/neu gene alterations have been the most frequently assessed prognostic factors during the last 10 years in breast cancer and have recently emerged as a management decision tool and a therapeutic target. There is still controversy over the best method to determine whether a tumor is HER-2/neu positive. Because of the increasing demand for HER-2/neu gene status determination in clinical practice, we compared HER-2/neu gene alterations at the DNA level (gene amplification) and the protein level (overexpression) in a panel of patients with lymph node-negative breast cancer who had received local radiotherapy alone, with no adjuvant therapy. METHODS: We tested 100 excised lymph node-negative breast tumors, using fluorescence in situ hybridization (FISH) with a biotinylated HER-2/neu DNA probe and immunohistochemical assays (IHC) with 2 different antibodies. RESULTS: The FISH frequency of HER-2/neu gene amplification was 15%, and the IHC frequency of overexpression was 21%. CONCLUSION: Although HER-2/neu amplification by FISH and HER-2/neu overexpression by IHC correlated well in this panel of lymph node-negative breast carcinomas, there were a number of discordant cases, pointing to the important need for determining HER-2/neu alteration for the future management of HER-2/neu-based clinical applications.     

Prognostic value of immunohistochemical expressions of p53, HER-2/neu, and bcl-2 in stage I non-small-cell lung cancer

The outcomes of patients with stage I non-small-cell lung cancer (NSCLC) vary greatly, with a 5-year survival rate of approximately 60%. This study evaluated a number of molecular markers that may aid in predicting prognosis in stage I NSCLC after surgical resection. Immunohistochemical (IHC) staining of p53, HER-2/neu, bcl-2 proteins was performed on paraffin-embedded sections from 85 stage I NSCLC patients who underwent surgery and were followed up for 32 to 44 (median, 39.0; mean, 37.1) months postoperatively. Differences in survival rates were evaluated by log rank test. The prevalence of p53, HER-2/neu, and bcl-2 expression in stage I NSCLC is 59%, 29%, and 46%, respectively. HER-2/neu expression is seen more frequently in adenocarcinomas, and bcl-2 is seen more frequently in squamous carcinomas. p53 and HER-2/neu expression in stage I NSCLC is associated with significantly short survival. Patients whose tumors were both p53 and HER-2/neu positive had the worst outcome, with a survival rate of only 20%, compared with 80% in those whose tumors were both p53 and HER-2/neu negative (P = .0003). The survival rates were 54% in patients who were p53 positive but HER-2/neu negative and 50% in those who were in p53 negative, HER-2/neu positive. The differences among these 4 groups were statistically significant (P =.001). Bcl-2 does not seem to be a prognostic factor for survival. Multivariate analysis showed that overexpression of p53 and HER-2/neu, presence of angiolymphatic invasion, and tumor size > 3.0 cm were independent factors predicting poor survival. p53 and HER-2/neu by IHC staining appear to be valuable prognostic markers in stage I NSCLC patients after surgery. The worst outcome was seen in patients who expressed both p53 and HER-2/neu, suggesting that these patients might benefit from additional adjuvant therapy.     

AQUA and FISH analysis of HER-2/neu expression and amplification in a small cell lung carcinoma tissue microarray

AIMS: Most small cell lung carcinoma (SCLC) patients have metastatic disease at the time of diagnosis and are faced with poor prognosis and limited treatment options. Reports of HER-2/neu gene amplification and overexpression in this malignancy have raised the possibility of applying targeted immunotherapy with trastuzumab, the monoclonal antibody used to treat metastatic breast cancer. However, a review of the studies measuring HER-2/neu gene amplification and protein expression in SCLC reveals discordant results. The aim of the present study was to re-examine HER-2/neu expression in SCLC in relation to gene copy number using the new, highly sensitive, immunofluorescence automated quantitative analysis (AQUA) technology. METHODS AND RESULTS: Fluorescence in situ hybridization (FISH) was used to measure HER-2/neu gene copy number and amplification status and AQUA was used to measure protein expression in a series of 23 SCLC tumours on a tissue microarray. None of the 17 SCLC specimens assessable by FISH exhibited HER-2/neu gene amplification as defined by a HER-2/neu/chromosome 17 ratio = or > 2. Twelve of 17 (70.1%) SCLC samples were polysomic for chromosome 17 with corresponding increases in HER-2/neu gene copy numbers. Intermediate levels of protein expression corresponding to AQUA scores in the range of 4-24 were detected in all 23 specimens. High protein expression levels corresponding to AQUA scores up to 83, observed previously in association with gene amplification and poor prognosis in breast cancer cases, were not detected in the present study. No statistically significant association was observed between absolute chromosome 17 or HER-2/neu gene copy numbers and protein expression levels in tumour cells (P > 0.45). CONCLUSIONS: The lack of gene amplification and robust HER-2/neu protein expression in SCLC tumour cells in this series does not suggest a prominent role for the HER-2/neu gene in SCLC tumour progression and does not support the general applicability of targeted immunotherapy with trastuzumab to this malignancy.     

HER-2/neu protein expression and gene alteration in stage I-IIIA non-small-cell lung cancer: a study of 140 cases using a combination of high throughput tissue microarray, immunohistochemistry, and fluorescent in situ hybridization.

Regarding HER-2/neu expression (gene or protein level) in lung cancer, several studies with inconsistent results have been recently reported, partially due to variable techniques used and/or heterogeneous populations examined. The objective of this study was to examine HER-2/neu expression in a well-defined cohort of non-small-cell lung cancers (NSCLC) and in nonneoplastic lung tissue utilizing a combination of high-density tissue microarray, immunohistochemistry (IHC), and fluorescent in situ hybridization (FISH) under uniform test conditions. One hundred forty stage I-IIIA primary NSCLCs and 38 non-neoplastic lung samples were examined. IHC, using an FDA-approved Hercept monoclonal antibody kit, was performed and HER-2/neu gene alteration was assessed by FISH. The association of expression of HER-2/neu with clinicopathologic parameters was analyzed. Ninety-four percent of tumor samples (131/140) were fully interpretable after tissue processing. Twenty-five of them (19%) overexpressed (2+, 3+) HER-2/neu, while 106 (81%) had no or weak expression. All thirty-four interpretable non-neoplastic lung samples were negative for HER-2/neu alteration at protein and gene level. HER-2/neu protein overexpression correlated well with HER-2/neu gene amplification (r =.83, P < 0.001). HER-2/neu overexpression was significantly associated with histologic subtype: 19 adenocarcinomas (19/82, 23%) versus 4 squamous cell carcinomas (4/44, 9%) overexpressed Her-2/neu (P = 0.04). Statistical significance was observed between HER-2/neu expression and tumor differentiation, with strong positive (3+) expression observed more frequently in poorly differentiated tumors (P = 0.01). Patients with HER-2/neu abnormalities, particularly HER-2/neu gene amplification, exhibited a shorter survival (P = 0.043). The statistically significant difference (P < 0.005) between HER-2/neu alteration in tumor samples(25/131, 19%) and in the nonneoplastic tissue (0/34, 0%) implies that HER-2/neu may have a role in the carcinogenesis of NSCLC. The findings provide evidence supporting the hypothesis that the HER-2/neu receptor may represent a useful molecular target in the treatment of NSCLC. The significant association of HER-2/neu expression and gene amplification with poorly differentiated carcinoma compared with well differentiated carcinoma suggests that HER-2/neu may be involved in NSCLC tumor evolution. Patients with HER-2/neu gene amplification and strong positive expression of HER-2/neu protein showed a strong tendency toward shorter survival.     

HER-2/neu oncogene amplification in stage I and stage III ovarian papillary serous carcinoma.

Oncogene amplification has been implicated in the genesis and progression of many cancers. Overexpression of the HER-2/neu proto-oncogene occurs in 20-30% of ovarian epithelial cancers, in which it may be of prognostic significance. Oncogene overexpression is traditionally studied using immunohistochemistry. In this study we used fluorescent in situ hybridization (FISH) to determine HER-2/neu amplification in ovarian papillary serous carcinoma and compared the frequency of amplification in two stages of the disease. Archival tissues from 23 cases of papillary serous ovarian carcinoma (9 cases of stage I and 14 cases of stage III) were analyzed by FISH using a HER-2/neu probe and a chromosome 17 centromere control probe. Determination of the level of amplification was performed according to the standard protocols of the Cytogenetics Laboratory at Rhode Island Hospital. Of the 23 cases successfully analyzed, the frequency of amplification among stage I tumors was 22% (2/9) and the frequency of amplification among stage III tumors was 71% (10/14). These results are significant (P = 0.036). The frequency of stage I tumors among amplified cases was 17% (27/12) and the frequency of stage III tumors among amplified cases was 83% (10/12). This study not only confirms the presence of a subset of ovarian papillary serous carcinoma with HER-2/neu gene amplification, but it also indicates that HER-2/neu oncogene amplification is more likely to be associated with a more advanced stage. Thus, the present data are consistent with the hypothesis that HER-2/neu amplification, similar to HER-2/neu protein over expression, is a prognostic marker of poor outcome.     

Change of HER-2/neu status in a subset of distant metastases from breast carcinomas

It is assumed that HER-2/neu status remains consistent in breast carcinoma during metastatic spread, but in most previous studies primary tumours were compared with concurrent regional lymph node metastases. The present study investigated 31 breast carcinomas and their corresponding lymph node and distant metastases for HER-2/neu status by immunohistochemistry (HercepTest) and fluorescence in situ hybridization (FISH) (PathVysion). In 14 cases, serum HER-2/neu (SHER-2) was measured sequentially using the Bayer Immuno 1 HER-2/neu assay. Comparing HER-2/neu immunohistochemistry of primary tumours and distant metastases case by case, increased HER-2/neu expression was found in the distant metastases in 15 cases (48.4%), three (9.7%) of which showed an increase from score 0 to score 3+. In contrast, lymph node metastases showed the same HER-2/neu expression as the primary tumours, confirmed by FISH. Two cases, which showed HER-2/neu score 3+ and HER-2/neu amplification in the primary tumours, revealed increased SHER-2 levels above 50 ng/ml at the first measurement. Five of the 14 cases (36%) showed an increase of SHER-2 above 50 ng/ml towards the end of the patients' life. On the basis of these results, there is evidence that in a subset of breast carcinomas, HER-2/neu amplification and overexpression occur de novo in distant metastases at a late disease stage.     

Assessment of HER‐2/neu overexpression and/or gene amplification in breast carcinomas: should in situ hybridization be the method of choice?

AIMS: Since the release of Herceptin, pathology laboratories have been requested to test breast carcinomas for HER-2/neu overexpression and/or gene amplification. Standardized IHC and FISH are mandatory in order to get reliable results, but there are problems even with standardized procedures. We decided to evaluate the two methods to determine which, or possibly if both, should be the primary investigation method(s). METHODS AND RESULTS: The material consisted of 215 primary invasive breast carcinomas with complete clinical follow-up of 15 years. HER-2/neu protein expression was determined for all specimens, whereas FISH for assessing HER-2/neu gene signal number was done in 165 cases. IHC was double-checked with two or three different antibodies in 35 tumours, including all cases with discrepancies between IHC and FISH. Among these, there were discrepancies in a third. IHC overexpression of HER-2/neu was found in 13% and gene amplification in 18%. Discordance between IHC and FISH was found in 11 cases (8%). Five tumours were IHC+/FISH- and six were IHC-/FISH+. IHC and FISH positive cases as well as FISH only positive tumours had the same prognosis respecting survival. Tumours with >2 but 4 gene signals per nucleus. In contrast, cases with IHC overexpression without gene amplification had a prognosis similar to that of IHC-/FISH- tumours. CONCLUSIONS: From our data, it seems to be more important to assess HER-2/neu gene amplification than IHC overexpression. Failure to detect FISH-amplified (IHC-negative) cases would have an adverse effect on the survival of these patients. On the other hand, IHC overexpression tumours without gene amplification appear to belong to a better prognostic group, and failure to detect them would probably not have a negative effect on the survival of these women. Even though FISH is a more complex and expensive procedure, it should be considered the method of choice for primary assessment of HER-2/neu status in breast cancer patients.     

Overexpression/amplification of HER-2/neu is uncommon in hepatocellular carcinoma

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most prevalent fatal cancers in the world. Despite advances in early diagnosis and improvements in surgical techniques, the survival of patients with HCC even after resection is poor because of the high incidence of recurrences. Therefore, the identification of prognostic factors may be helpful in the development of new treatment protocols. AIMS: To investigate HER-2/neu status in HCC by immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH), and to explore the possibility of using trastuzumab in the treatment of HCC. METHODS: Eight hundred and sixty eight surgical samples from patients with primary HCC were examined for their HER-2/neu status. IHC for HER-2/neu was performed with the HercepTest kit; FISH analysis was performed with the PathVysion HER-2 DNA probe kit. The correlations between HER-2/neu overexpression and clinicopathological characteristics were analysed statistically. RESULTS: HER-2/neu overexpression was detected in 21 (2.42%) of the 868 primary HCCs. Only one specimen showed HER-2/neu gene amplification by FISH. No significant associations were found between HER-2/neu overexpression and the clinicopathological parameters. CONCLUSIONS: There is a low frequency of HER-2/neu overexpression/amplification in HCC. There appears to be no role for HER-2/neu as a prognostic marker and no benefit of anti-HER-2/neu trastuzumab treatment in patients with HCC.     

Correlation of Mammographic Calcifications with HER-2/neu Overexpression in Primary Breast Carcinomas

HER-2/neu is a valuable therapeutic and prognostic marker in primary breast carcinomas. The aim of this study was to evaluate the association between mammographic calcifications and HER-2/neu overexpression in primary breast carcinomas and assess its clinical perspective. A retrospective study of 152 preoperative mammograms in patients with breast carcinoma was performed. Expression of HER-2/neu was determined by immunohistochemical staining on 152 tissues that comprised specimens of 11 ductal carcinoma in situ (DCIS) and 141 primary invasive carcinomas. Mammographic calcifications were evaluated according to the Breast Imaging Reporting and Data System (BI-RADS), fourth edition. Calcifications were found in 73 (48.0%) out of 152 patients by mammography finding. Calcifications were more common in carcinomas with HER-2/neu overexpression (45:73, 61.6%) than in those without HER-2/neu overexpression (28:79, 35.4%; P = 0.001). Of the 73 carcinomas with calcifications on mammography, mass with spiculated margin as an associated finding of calcifications was more significantly frequent in carcinomas with HER-2/neu overexpression (15 of 45, 33.3%) than in those without HER-2/neu overexpression (2 of 28, 7.1%; P = 0.036). Fine linear morphology was more common in carcinomas with HER-2/neu overexpression (15:45, 33.3%) when compared with those without HER-2/neu overexpression (2:28, 7.1%; P = 0.036). Clustered distribution of calcifications was more common in carcinomas with HER-2/neu overexpression (26:45, 57.8%) compared with carcinomas without HER-2/neu overexpression (6:28, 21.4%; P = 0.048). Mammographic calcifications are correlated with HER-2/neu overexpression in primary breast carcinomas. Calcifications detected during screening mammography are not only of diagnostic value but of use in determining therapeutic options and prognosis.     

Intratumoral heterogeneity of her-2/neu in invasive mammary carcinomas using fluorescence in-situ hybridization and tissue microarray

Fluorescence in-situ hybridization is increasingly being used to determine HER-2/neu status in patients with breast carcinoma. The possibility that intratumoral heterogeneity of HER-2/neu gene amplification may potentially contribute to inaccurate assessment of HER-2/neu status was investigated in routine cases of invasive mammary carcinomas. From 169 representative formalin-fixed, paraffin-embedded blocks of invasive duct mammary carcinomas with grade 3 architecture, 48 cases were analyzed by fluorescence in-situ hybridization and 59 analyses were performed. Intratumoral heterogeneity for HER-2/neu gene amplification was demonstrated in only 5 (16%) of 31 cases where morphologically similar areas of a single tumor were analyzed. We conclude from this study that intratumoral heterogeneity of HER-2/neu gene amplification is a demonstrable but relatively uncommon occurrence. For invasive mammary carcinomas, the accurate assessment of HER-2/neu status by fluorescence in-situ hybridization analysis is not significantly confounded by intratumoral heterogeneity of HER-2/neu gene amplification in individual tumors.     

Analysis of HER-2/neu amplification in endometrial carcinoma by chromogenic in situ hybridization. Correlation with fluorescence in situ hybridization, HER-2/neu, p53 and Ki-67 protein expression, and outcome.

Fluorescence in situ hybridization (FISH) is the most widely used technique to detect HER-2/neu gene amplification; however, it is only available in some institutions. In contrast, chromogenic in situ hybridization (CISH) can be evaluated by routine light microscopy. In endometrial carcinoma there are few data concerning HER-2/neu status and prognosis. Therefore, we determined HER-2/neu gene status by CISH using a digoxigenin-labelled probe on 60 formalin-fixed paraffin-embedded endometrial carcinomas. The data were compared with the immunohistochemistry of HER-2/neu (A0485, TAB250), p53, Ki-67, clinicopathological factors, and survival. By conventional light microscopy, HER-2/neu amplification (>/=6 copies >50% cancer cells) was detected in 14% (8/59) tumours, HER-2/neu overexpression (>10% cells moderate/strong complete membrane staining) in 22% (13/60) for A0485, and 18% (11/60) for TAB250, p53 (>10% +cells) in 61% (36/59), and Ki-67 (>50% +cells) in 50% (30/60). Discordant cases for CISH and immunohistochemistry, as well as all (2+) were further analysed by FISH (Vysis). Among 10 cases (2+) and not amplified by CISH, two showed low-level amplification by FISH. Significant correlation was found between amplification and protein overexpression (P相似文献   

Expression of apoptosis-related markers and HER-2/neu in thymic epithelial tumours

AIMS: To correlate the expression of a series of apoptotic and oncogene markers (including p53, Bcl-2, BAX, Bcl-XL, p21WAF,1/CIP1, cyclin D1, HER-2/neu) in thymic epithelial tumours with histological type, stage and resectability and to determine whether the information on HER-2/neu would be valuable in identifying patients who are eligible for anti-HER-2/neu treatment. METHODS AND RESULTS: Immunohistochemical stains were performed on 16 cases of non-neoplastic thymus, 63 thymomas and 17 thymic carcinomas. Fluorescence in-situ hybridization (FISH) for HER2 was performed to validate the gene amplification. Eighteen thymomas were positive for p53 and 14 of them were low-expressors, with positive cells below 10%. All thymic carcinomas revealed over-expression of p53 with positive cells either between 10% and 50% or >50%. The expression of p53 correlated with histological type and stage in thymoma. In both thymoma and thymic carcinoma, there was a statistically significant correlation between p53 status and resectability, with low expressors having a higher likelihood of being resectable. Thymic carcinomas, regardless of the histological subtypes, uniformly expressed Bcl-2, while thymomas showed no or only weak cytoplasmic immunoreactivity. Most thymomas and thymic carcinomas were negative for Bcl-XL, p21WAF,1/CIP1 and cyclin D1. The expression of BAX was inconsistent among different histological types. Nine thymic carcinomas revealed membranous positivity for HER-2/neu, but no HER2 gene amplification could be demonstrated by FISH in any of the cases. CONCLUSIONS: p53 and Bcl-2 are more implicated in the development of thymic carcinoma than thymoma. The higher level of p53 expression and the strong immunopositive pattern of Bcl-2 in thymic carcinomas have potential value in the differential diagnosis and prediction of aggressiveness and resectability. On account of the absence of HER2 amplification, patients would probably not benefit from anti-HER-2/neu treatment.     

Tyrosine kinase activation in breast carcinoma with correlation to HER-2/neu gene amplification and receptor overexpression.

The HER-2/neu oncogene encodes a transmembrane receptor with intrinsic tyrosine kinase activity. A pilot study was performed to investigate downstream effects of HER-2/neu (or related growth factor receptor) activation by identifying phosphorylated tyrosine. Fifty-four breast carcinomas were evaluated for HER-2/neu overexpression by the HercepTest (Dako, Carpinteria, CA) and the monoclonal CB11 antibody (Ventana, Tucson, AZ). Phosphotyrosine (an indication of tyrosine kinase activity) was detected by an antiphosphotyrosine mouse monoclonal antibody (Upstate Biotechnology, Lake Placid, NY). The gene amplification status was evaluated in 50 of the 54 cases by fluorescence in situ hybridization (FISH) using the Ventana gene probe. The HER-2/neu oncogene amplification was detected in 28% (14 of 50) of cases. Of the 14 cases showing oncogene amplification, tyrosine kinase activity was detected in 9 (64.2%) cases. There was moderate agreement between HER-2/neu gene amplification and tyrosine kinase activity (kappa = 0.43). Immunohistochemical staining of 3+ (with both HercepTest and CB11) showed better agreement with HER-2/neu oncogene amplification and increased tyrosine kinase activity than 2+ immunohistochemical staining. Overall, oncogene amplification and overexpression correlated with increased tyrosine kinase activity, supporting the mechanism of tyrosine kinase activation by HER-2/neu amplification and overexpression. However, 7 cases showing increased tyrosine kinase activity did not show gene amplification or 3+ receptor expression (by either HercepTest or CB11), raising the possibility of other growth factor receptors operating via the tyrosine kinase pathway. There was no apparent correlation between tyrosine kinase activity and hormone receptor status (estrogen or progesterone). Increased tyrosine kinase activity is more commonly associated with higher-grade tumors and thus may correlate with aggressive biologic behavior in breast carcinoma. The results of this pilot study suggest that a larger-scale investigation into downstream activation of tyrosine kinase and correlation to clinical outcome or response to Herceptin therapy may identify subsets of patients whose clinical response or outcome may be predicted by tyrosine kinase activation.     

Comparison of chromogenic in situ hybridisation with fluorescence in situ hybridisation and immunohistochemistry for the assessment of her-2/neu oncogene in archival material of breast carcinoma

The successful treatment of breast cancer is dependent upon a number of complex factors. Her-2/neu gene amplification is known to be one of the most common genetic alterations associated with breast cancer and its accurate determination has become necessary for the selection of patients for trastuzumab therapy.The aim of this study was to prove the consistency of chromogenic in situ hybridisation (CISH) technique after analyzing the overexpression of the Her-2/neu proto-oncogene in 100 invasive breast carcinomas and by comparing CISH results with immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH). Moreover, it was done to evaluate the possible correlation of estrogen (ERs) and progesterone receptors (PRs), the proliferation marker Ki67 and the tumour suppressor gene p53 with HER-2/neu status of these breast carcinomas.Of the 100 breast carcinomas that were analysed, 22 cases showed HER-2/neu amplification, 66 cases showed no amplification, whereas 12 cases were non-interpretable in both assays (FISH and CISH). Consequently, the overall concordance between FISH and CISH was 100%. Additionally, it was observed that when HER-2/neu gene was overexpressed, there was an association with negative PRs and ERs status, negative p53 protein expression and high Ki67 labelling index.It is concluded that patients with tumours scoring 2+ with the CBE356 antibody (borderline immunohistochemistry-tested cases) would also benefit from CISH as it is shown to be highly accurate, practical and can be easily integrated into routine testing in any histopathology laboratory. Finally, CISH represents an important addition to the HER2 testing algorithm.