A comparison of epidermal growth factor receptor (EGFR) and c-erbB-2 oncogene expression in head and neck squamous cell carcinomas

Epidermal growth factor receptor overexpression is common and not correlated to gene copy number in ependymoma

PURPOSE

The aim of this study was to investigate the epidermal growth factor receptor (EGFR) status in ependymoma specimens, as there is a need for new prognostic and druggable targets in this disease.

METHODS

Ependymomas (WHO grade II, n = 40; WHO grade III, n = 15) located spinal (n = 35), infratentorial (n = 14), and supratentorial (n = 6) of 53 patients with a median age of 40 (range, 2-79) years were analyzed for Ki-67, p53, and EGFR expression by immunohistochemistry using a tissue microarray and for EGFR gene copy number alterations/mutations. Results were correlated to clinical data.

RESULTS

EGFR overexpression was found in 30/60% of ependymomas depending on the antibody used and was more pronounced in WHO grade III. High EGFR gene copy number gains were found in 6 (11%) ependymomas with half of them being amplifications. EGFR amplified ependymomas displayed an EGFR overexpression with both antibodies in two of three cases. A missense mutation in exon 20 of EGFR (S768I) was detected in one amplified case.

CONCLUSIONS

EGFR is frequently overexpressed in ependymomas. Other mechanisms than amplification of the EGFR gene appear to contribute to EGFR overexpression in most cases. EGFR mutations may be present in a small subset of ependymomas.

Impact of epidermal growth factor receptor protein and gene alteration on Taiwanese hepatocellular carcinomas

BACKGROUND AND AIM

Epidermal growth factor receptor (EGFR) overexpression is associated with disease progression and poor survival in a variety of solid tumors. The role of EGFR in hepatocellular carcinoma (HCC) remains controversial.

METHODS

One hundred thirty-eight HCCs were analyzed for total EGFR (t-EGFR) and phospho-EGFR (p-EGFR) expression and gene amplification using immunohistochemistry and fluorescence in situ hybridization. The role of EGFR was analyzed in relation to the clinicopathological features.

RESULTS

Weak to strong p-EGFR immunostaining was noted in 42 of the 138 HCCs. p-EGFR expression correlated with alcoholism (P = 0.03) and chronic hepatitis B infection (P = 0.041). There was no correlation between t-EGFR expression and any of the clinicopathological features. Amplification of the EGFR gene was not identified in the 138 HCCs, but 39.1% of the HCCs showed balanced polysomy of both the EGFR gene and centromere 7. Moreover, 65 tumors showed > 2.2 copies per tumor cell. EGFR copy number gain (CNG) was significantly correlated with gender (P = 0.0491), tumor grade (P = 0.006), and vascular invasion (P = 0.005). HCCs with EGFR CNG also had a poor recurrence-free survival (RFS), as compared with HCCs without EGFR CNG (P = 0.031). When exploring the impact of gender, a significant association of EGFR CNG was found with tumor grade (P = 0.044) and cirrhosis (P = 0.015) exclusively in the male group only; however, the OS and RFS analysis show no significant difference between male and female groups.

CONCLUSIONS

EGFR CNG was related to crucial clinicopathological features and early recurrence, indicating that EGFR CNG might be a poor prognosis factor for Taiwanese HCC.

Assessment and prognostic analysis of EGFR, HER2, and HER3 protein expression in surgically resected gastric adenocarcinomas

Aim

To investigate the significance of epidermal growth factor receptor (EGFR), human epidermal growth factor receptor (HER)2, and HER3 expression on survival outcomes in Chinese gastric cancer patients.

Materials and methods

Formalin-fixed, paraffin-embedded specimens from 121 patients who underwent gastrectomy at Shanghai Renji Hospital from 2007–2010 were retrospectively examined. Fluorescence in situ hybridization and immunohistochemistry techniques were used to identify gene amplification and protein overexpression. Correlations between the expression or amplification of HER family genes and clinicopathological parameters were then determined using statistical analysis.

Results

EGFR protein overexpression, an increase in HER2 copy number and gene amplification, and HER3 protein overexpression were identified in 33.1%, 17.4%, and 62.0% of samples, respectively. Statistical analysis showed a significant association between EGFR expression and tumor invasion depth or tumor stage. HER2 was also shown to be significantly associated with the tumor grade. In addition, EGFR protein overexpression was found to be significantly associated with worse overall survival (P=0.03).

Conclusion

The HER family members showed a high expression in gastric cancer. EGFR protein expression was associated with overall survival.

Membranous expression of Her3 is associated with a decreased survival in head and neck squamous cell carcinoma

Background

Head and neck squamous cell carcinoma (HNSCC) still remains a lethal malignancy benefiting from the identification of the new target for early detection and/or development of new therapeutic regimens based on a better understanding of the biological mechanism for treatment. The overexpression of Her2 and Her3 receptors have been identified in various solid tumors, but its prognostic relevance in HNSCC remains controversial.

Methods

Three hundred eighty-seven primary HNSCCs, 20 matching metasis and 17 recurrent HNSCCs were arrayed into tissue microarrays. The relationships between Her2 and Her3 protein expression and clinicopathological parameters/survival of HNSCC patients were analyzed with immunohistochemistry.

Results

Her3 is detected as either a cytoplasmic or a membranous dominant expression pattern whereas Her2 expression showed uniform membranous form. In primary tumor tissues, high membranous Her2 expression level was found in 104 (26.9%) cases while positive membranous and cytoplasmic Her3 expression was observed in 34 (8.8%) and 300 (77.5%) samples, respectively. Membranous Her2 expression was significantly associated with histological grade (P = 0.021), as grade 2 tumors showed the highest positive expression. Membranous Her3 over-expression was significantly prevalent in metastatic tissues compared to primary tumors (P = 0.003). Survival analysis indicates that membranous Her3 expression is significantly associated with worse overall survival (P = 0.027) and is an independent prognostic factor in multivariate analysis (hazard ratio, 1.51; 95% confidence interval, 1.01-2.23; P = 0.040).

Conclusions

These results suggest that membranous Her3 expression is strongly associated with poor prognosis of patients with HNSCC and is a potential candidate molecule for targeted therapy.

Epidermal growth factor receptor and HER-2/neu status by immunohistochemistry and fluorescence in situ hybridization in adenocarcinomas of the biliary tree and gallbladder

Adenocarcinomas of the biliary tract and gallbladder are aggressive tumors with a poor prognosis. Standard chemotherapy often offers minimal benefit. Because epidermal growth factor receptor and HER-2/neu antagonists have been successfully used in adenocarcinomas from other sites, their use in cholangiocarcinoma can be potentially beneficial. This study examines the epidermal growth factor receptor and HER-2/neu expression and the epidermal growth factor receptor gene copy number in biliary tract adenocarcinomas. Fifty-one formalin-fixed, paraffin-embedded cases of adenocarcinomas (26 intrahepatic, 19 extrahepatic, 6 gallbladder) were stained with monoclonal antibodies against epidermal growth factor receptor and HER-2/neu. Fluorescence in situ hybridization analysis was performed in 37 cases using probes directed against epidermal growth factor receptor and centromeric region of chromosome 7. Epidermal growth factor receptor expression was present in 41 (80%) cases, with moderate or strong epidermal growth factor receptor staining in 30 (59%) cases. HER-2/neu was positive in 2 (4%) cases. Fluorescence in situ hybridization analysis showed gain in epidermal growth factor receptor gene copy number in 17 (46%) tumors. Of the latter, 1 showed gene amplification, whereas all others showed gain in chromosome 7, indicating balanced polysomy. Epidermal growth factor receptor overexpression by immunohistochemistry correlated significantly with epidermal growth factor receptor copy number by fluorescence in situ hybridization (P = .02). HER2/neu expression is uncommon in these tumors.

Her-2 immunohistochemical expression in oral squamous cell carcinomas is associated with polysomy of chromosome 17, not Her-2 amplification

Based on the prognostic role of Her-2 amplification and protein overexpression in breast cancer, various studies have been performed in oral squamous cell carcinomas (OSCC) with inconsistent results. As in invasive breast carcinomas Her-2 overexpression has been related to an increased number of chromosome 17 copies, a common chromosomal alteration in OSCC, we evaluated the association between polysomy 17 and Her-2 protein expression in a series of primary OSCC. Forty-one incisional biopsies of primary OSCC were included in the study. Protein expression was evaluated immunochistochemically with CB11 mouse monoclonal anti-human antibody. The reaction was arbitrarily characterized as absent, faint, moderate, and strong, and staining pattern as cytoplasmic and membranous. Positive cases were analyzed by chromogenic in situ hybridisation (CISH) to access Her-2 status. The association between polysomy 17 and Her-2 expression was checked by Fisher's exact test. Four cases were negative and 37 cases were positive for Her-2. Staining was faint in 15 cases and moderate in 22 cases. CISH showed that all cases with faint staining were diploid, while from the cases with moderate staining 10 were diploid and 12 polysomic for chromosome 17. Thirteen cases showed purely cytoplasmic staining, while in 24 there were areas of both cytoplasmic and membranous staining. There was a statistically significant correlation between intensity of the reaction and polysomy 17 (P = 0.0036), in particular for cases with both cytoplasmic and membranous staining (P = 0.0128). In some OSCC Her-2 immunohistochemical expression may be associated with chromosome 17 polysomy and not Her-2 amplification.

Targeting EGFR resistance networks in head and neck cancer

A core set of oncoproteins is overexpressed or functionally activated in many types of cancer, and members of this group have attracted significant interest as subjects for development of targeted therapeutics. For some oncoproteins such as EGFR/ErbB1, both small molecule and antibody agents have been developed and applied in the clinic for over a decade. Analysis of clinical outcomes has revealed an initially unexpected complexity in the response of patients to these agents. Diverse factors, including developmental lineage of the tumor progenitor cell, co-mutation or epigenetic modulation of genes encoding proteins in an extended EGFR signaling network or regulating core survival responses in individual tumors, and environmental factors including inflammatory agents and viral infection, all have been identified as modulating response to treatment with EGFR-targeted drugs. Second and third generation therapeutic strategies increasingly incorporate knowledge of cancer type-specific signaling environments, in a more personalized treatment approach. This review takes squamous cell carcinoma of the head and neck (SCCHN) as a specific example of an EGFR-involved cancer with idiosyncratic biological features that influence design of treatment modalities, with particular emphasis on commonalities and differences with other cancer types.

Epidermal growth factor receptor expression and gene copy number in conventional hepatocellular carcinoma

Epidermal growth factor receptor (EGFR) is frequently overexpressed in hepatocellular carcinoma, but its relationship with EGFR gene copy number has not been studied. This study examined EGFR expression and gene copy number in hepatocellular carcinoma and evaluated their relationship to clinicopathologic features in 76 tumors. Moderate to strong expression of EGFR was observed by immunohistochemical analysis in 50 (66%) of 76 hepatocellular carcinomas. Fluorescence in situ hybridization (FISH) showed extra EGFR gene copies in 17 (45%) of 38 tumors. This was accompanied by gains of chromosome 7, indicating that this was the result of balanced polysomy rather than gene amplification. There was no correlation between EGFR expression by immunohistochemical analysis and gene copy number by FISH. EGFR expression showed borderline association with cirrhosis but not with other clinicopathologic parameters examined. EGFR overexpression is present in a majority of hepatocellular carcinomas, suggesting a role for EGFR antagonists in therapy. The increased expression does not correlate with an increase in the EGFR gene copy number.

An investigation of the differential expression of Her2/neu gene expression in normal oral mucosa, epithelial dysplasia, and oral squamous cell carcinoma in Taiwan

BACKGROUND

Her2/neu was thought to be a proto-oncogene with sequence homology to epidermal growth factor receptor (EGFR). Its overexpression was seen in many cancers and referred to regimens of anticancer therapy. The aim of this study was to investigate whether the abnormal expression existed in oral carcinogenesis.

METHODS

Immunohistochemistry (IHC) was used to detect Her2/neu expression in normal oral mucosa (NOM) (n = 20), oral precancerous lesions of epithelial dysplasia (ED) (n = 20), and oral squamous cell carcinoma (OSCC) (n = 30). The association of clinicopathologic covariates of areca use, tumor size, neck lymph node metastasis, differentiation and stages of cancer with the expression of Her2/neu was examined. The significance of Neu immunoreactivity in different groups or with different covariates was investigated using Fisher's exact test.

RESULTS

Her2/neu immunoreactivity was very low with Her2/neu(+) in 10% (2/20) of NOM cases and in 25% (5/20) of ED cases, respectively. The Her2/neu expression was high in OSCC cases, with 40% (12/30) of Her2/neu(+) and 10% (3/30) of Her2/neu(++). Significant difference was observed between NOM/ED and OSCC cases (p < 0.05). All clinicopathologic covariates showed no significant relation to the expression of Her2/neu in OSCC cases.

CONCLUSION

These findings suggested a dynamic change in Her2/neu expression during the development of OSCC. The overexpression of Her2/neu can be used as a marker in distinguishing NOM/ED from OSCC.

The Biology of Epidermal Growth Factor Receptor and its Value as a Prognostic/predictive Factor

Receptor tyrosine kinases play a major role in human carcinogenesis. Overexpression of the epidermal growth factor receptor (EGFR) has been associated with poor clinical outcome in several types of cancer. In principle, as with HER2, the EGFR status of a tumor should predict the likelihood of response to EGFR-targeted therapy. However, clinical data have failed to demonstrate a relationship between EGFR expression and response to the EGFR-targeted compounds cetuximab, gefitinib and erlotinib. Recently, patients reported to be EGFR negative have been shown to respond to cetuximab. Possible explanations include methodological failures or most likely heterogeneity and complexity of the mechanisms of EGFR-mediated molecular carcinogenesis. Immunohistochemistry is the most widely used method for measuring EGFR expression; however, its value is limited by lack of methodological standardization. Other approaches to measuring EGFR such as amplification assays are currently being introduced but need further testing before they can enter clinical practice. Mutational analysis seems also fruitful in predicting response to anti-EGFR small molecules. Further work is needed to identify how EGFR contributes to the carcinogenic and metastatic processes.

Prognostic impact ofHER-2/neu expression on squamous head and neck carcinomas

BACKGROUND

HER-2/neu gene amplification and protein overexpression have been identified in various solid tumors, but its prognostic relevance in head and neck squamous cell carcinoma (HNSCC) is still controversial.

METHODS

The study investigated the expression of HER-2/neu oncoprotein in HNSCC and sought possible correlations to various clinicopathologic parameters. Expression of HER-2/neu oncoprotein was assessed in archival tumor tissues from 87 untreated HNSCC patients by immunohistochemical technique. Data were correlated with both the clinicopathologic parameters and patient survival.

RESULTS

A high membranous HER-2/neu protein expression level was found in 39% of patients. Multivariate analysis indicated that HER-2/neu protein expression and pN lymph-node status were independent prognostic factors for disease-free survival.

CONCLUSIONS

HER2/neu overexpression and its relationship with survival suggest that new therapeutic approaches targeting epidermal growth factor receptor (EGFR) family receptors could provide a new way of treating HNSCC patients with HER2/neu-positive neoplastic lesions.

Expression of epidermal growth factor receptor in squamous cell carcinomas of the anal canal is independent of gene amplification

Immunohistochemical detection of expression of the epidermal growth factor receptor (EGFR) has been utilized to identify eligible patients with solid malignant tumors, including colorectal adenocarcinoma, for monoclonal antibody therapy (eg, cetuximab). The EGFR status in squamous cell carcinoma of the anal canal, an uncommon malignancy traditionally treated with chemoradiation, has not been well investigated. In this study, 38 primary squamous cell carcinomas of the anal canal were immunohistochemically examined for EGFR expression and analyzed by fluorescence in situ hybridization (FISH) for EGFR gene copy numbers. The results showed a variable degree of EGFR expression in 21 (55%) tumors, among which 13 (62%) cases exhibited a 2+ to 3+ staining pattern according to the Dako EGFR phamDx interpretation guide. There were no significant differences among tumors stratified by stage, degree of keratinization, or tissue block storage times. FISH analysis showed that none of the 34 cases with interpretable results had EGFR gene amplification. Increased gene copy numbers due to polysomy 7 were seen in seven of 18 (39%) cases that expressed EGFR protein and four of 16 (25%) cases that did not (P=0.3876). Ten (56%) tumors with positive EGFR staining showed a balanced disomy 7 pattern and one case with monosomy 7 exhibited strong EGFR expression (3+). These results demonstrate that EGFR is overexpressed in more than one-half of the squamous cell carcinomas of the anal canal through mechanisms other than gene amplification. These observations may have important therapeutic implications since EGFR-based targeted therapies have shown promise for other malignant neoplasms.

Immunohistochemical expression of EGFR and p-EGFR in oral squamous cell carcinomas

Epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor of the ErbB family, which is expressed or highly expressed in a variety of solid tumors, including oral cancers. High EGFR expression has been correlated with tumor size, metastasis and survival. In recent years, EGFR has been considered a promising target for monoclonal antibody therapy. A total of 52 patients with oral squamous cell carcinoma (OSCC) were selected for EGFR and phosphorylated EGFR (p-EGFR) detection. Immunohistochemical staining was performed to evaluate EGFR and p-EGFR expression. Positive EGFR and p-EGFR staining was present in 92.3% (48/52) and 98.0% (51/52) of all cases, respectively. High EGFR and p-EGFR expression was present in 63.4% (33/52) and 69.2% (36/52) of all cases, respectively. EGFR and p-EGFR expression did not correlate with the clinical factors tumor stage, regional lymph node metastasis, or distant metastasis. However, a statistically significant correlation was identified between high EGFR expression and the pathologic factor tumor invasion. As a conclusion, the majority of OSCCs highly express EGFR and p-EGFR, indicating the importance of studying the efficacy of anticancer therapy targeting these signal factors.

Role of Epidermal Growth Factor Receptor Pathway–Targeted Therapy in Patients With Recurrent and/or Metastatic Squamous Cell Carcinoma of the Head and Neck

The development of epidermal growth factor receptor (EGFR) inhibitors was greeted with tremendous enthusiasm in the therapy of squamous cell carcinoma of the head and neck (SCCHN) based on the nearly universal expression of this protein, the negative prognostic associations with expression, and robust preclinical data. Clinical trials to date have demonstrated modest activity of these drugs as single agents with reproducible major response rates of 5% to 15% in SCCHN depending on agent, dose, and schedule. The biology of responsiveness to these agents remains unclear, although an association of development of cutaneous toxicity with positive outcome has been reported repeatedly. Nevertheless, molecular markers of response or resistance have yet to be fully delineated. In the near future, phase III clinical trials will elucidate the role of these agents in second-line recurrent and/or metastatic (R/M) disease, the combination of EGFR inhibitors with other therapeutic strategies will be broadly advanced, and a set of molecular predictors of benefit will begin to emerge. This article will review the progress in utilization of EGFR inhibitors in R/M SCCHN.

PIK3CA mutations in head and neck squamous cell carcinoma

PURPOSE

Recent studies have reported high frequencies of somatic mutations in the phosphoinositide-3-kinase catalytic alpha (PIK3CA) gene in several human solid tumors. Although gene amplifications of PIK3CA have been reported in head and neck squamous cell carcinoma (HNSCC), small mutation of the gene has not been evaluated in HNSCC previously. In this study, we examined the mutation frequency of PIK3CA in HNSCC.

EXPERIMENTAL DESIGN

More than 75% of the somatic mutations of PIK3CA are clustered in the helical (exon 9) and kinase domains (exon 20). To investigate the possible role of PIK3CA in HNSCC tumorigenesis, exons 1, 4, 5, 6, 7, 9, and 20 of the gene were analyzed by direct genomic DNA sequencing in 38 HNSCC specimens.

RESULTS

We identified four missense mutations in the seven exons of PIK3CA from 38 HNSCC specimens (11%). Three of the four mutations (i.e., H1047R, E542K, and E545K) have been previously reported as hotspot mutations. The remaining novel mutation, Y343C, is identified at exon 4 nucleotide 1028 A --> G. Three of the four mutations were shown to be somatic, whereas the fourth mutation (H1047R) was identified in a cell line. Interestingly, three of the four mutations identified were in pharyngeal cancer samples.

CONCLUSIONS

These data provide evidence that oncogenic properties of PIK3CA contribute to the carcinogenesis of human head and neck cancers, especially in pharyngeal cancer. A specific kinase inhibitor to PIK3CA may potentially be an effective therapeutic reagent against HNSCC or pharyngeal cancer in particular.

Epidermal growth factor receptor directed therapy in head and neck cancer

Squamous cell head and neck cancer (SCCHN) is the seventh most common cause of cancer death worldwide and its incidence is rising rapidly in developing countries. Despite recent advances in managing locally advanced SCCHN, patients with recurrent and metastatic SCCHN have a poor prognosis and little progress has been made its management. Epidermal growth factor receptor (EGFR) has been implicated in the pathogenesis of SCCHN and is a marker of poor prognosis. Recent advances in targeted therapeutics against EGFR are being investigated clinically. In this article, we review the different modalities utilized to inhibit EGFR signaling in SCCHN, including small molecule tyrosine kinase inhibitors, monoclonal antibodies, anti-sense therapy and immunotoxin conjugates. Monotherapy with EGFR inhibitors has demonstrated response rates between 5 and 15% in advanced SCCHN. However, combining EGFR inhibitors with cytotoxic chemotherapy or radiation therapy appears to augment response rates and survival. With the foundation for the use of EGFR inhibitors laid in these studies, future studies will need to optimize the delivery of these agents in combination with conventional therapies.

Assessing epidermal growth factor receptor expression in tumours: What is the value of current test methods?

Over-expression of the epidermal growth factor receptor (EGFR) in tumours is associated with aggressive disease and poor clinical prognosis. In theory, the EGFR status of a tumour provides an indication of the likelihood of response to EGFR-targeted therapy. However, the clinical data do not support a relationship between EGFR expression and response to EGFR-targeted therapies cetuximab, gefitinib and erlotinib. Recently, patients who appear to lack EGFR expression have been shown to respond to cetuximab. Possible causes for this paradox include false negative results due to a lack of sensitivity in the detection system, heterogeneity of EGFR expression within the tumour and specific mutations that mediate response to the tyrosine kinase inhibitors. Immunohistochemistry is the most reliable assay for EGFR expression but its interpretation is confounded by the lack of non-standard techniques. Other approaches for measuring EGFR expression can be considered at best exploratory at this point. Further work is needed to identify how EGFR contributes to carcinogenic and metastatic processes. As tumours that appear to be EGFR negative can respond to cetuximab, there is some doubt as to the usefulness of immunohistochemistry as a screen to select patients for treatment. Histopathology will continue to be essential for unravelling the role of this enigmatic molecule and refining its status as a legitimate target in cancer therapy.

MUC4 and ErbB2 expression in squamous cell carcinoma of the upper aerodigestive tract: correlation with clinical outcomes

OBJECTIVES/HYPOTHESIS

Expression of the membrane mucin MUC4 has been associated with a variety of malignancies, including squamous cell carcinoma of the upper aerodigestive tract. MUC4 modulates cell signaling pathways as an intramembrane ligand of ErbB2. The hypotheses of the study were that MUC4 expression would correlate with ErbB2 expression and that MUC4 expression would correlate with clinical outcomes in squamous cell carcinoma of the upper aerodigestive tract.

STUDY DESIGN

Retrospective chart review was combined with immunohistochemical analysis of paraffin-embedded tumor specimens from patients treated with initial definitive surgical resection at an academic tertiary care medical center.

METHODS

MUC4 and ErbB2 receptor expression was localized by immunohistochemical studies using archival formalin-fixed and paraffin-embedded tissue. A limited number of fresh-frozen tissues were further analyzed by Western blot. Clinical outcomes and histopathological parameters were determined by retrospective chart review and correlated with immunohistochemical findings.

RESULTS

One hundred fifty-four patients were analyzed with a median follow-up of 12 months among 54 patients who died and 49 months among 100 surviving patients. Membrane expression of MUC4 and ErbB2 was seen in 12% and 13% of tumors, respectively. MUC4 expression was not correlated with pathological grade. A significant correlation was found between MUC4 expression and ErbB2 expression. Multivariate survival analyses revealed that patients whose tumors exhibited MUC4 membrane expression had statistically significant improvement in survival and longer time to recurrence compared with patients whose tumors did not express MUC4 as defined by immunohistochemical staining patterns. No correlations between ErbB2 expression and survival or recurrence were observed.

CONCLUSION

Patients with tumors that retain MUC4 expression exhibit improved survival and decreased recurrence in squamous cell carcinoma of the upper aerodigestive tract. Correlations between MUC4 expression patterns and ErbB2 expression are also observed, suggesting that MUC4-ErbB2 mediated cell signaling pathways may provide insights into this clinical result.

Immunohistochemical detection of EGFR in paraffin-embedded tumor tissues: variation in staining intensity due to choice of fixative and storage time of tissue sections

The epidermal growth factor receptor (EGFR) is highly expressed in a variety of solid malignant tumors and its expression has been correlated with disease progression and poor survival. With the advent of targeted therapies, especially IMC-C225 (Cetuximab), a monoclonal antibody (MAb) directed against the EGFR, there is an increasing interest in immunohistochemistry (IHC)-based EGFR screening methods using paraffin-embedded tumor specimens to select cancer patients eligible for treatment with Cetuximab. With the EGFRpharmDX kit, a complete assay for demonstration of EGFR is now available. Because no information about the preservation of the EGFR under various conditions of fixation is available, we performed a prospective study on a panel of commonly used fixatives to determine optimal tissue preservation protocols. The stability of the epitope on cut tissue sections stored for a period up to 24 month was also tested using material originating from patients with head and neck cancer, non-small-cell lung carcinomas, and colorectal adenocarcinomas. Depending on the fixative used and the time of storage of cut tissue sections, a variation in the determined level of EGFR expression was demonstrated compared with the most optimal fixation procedure.

Prognostic value of epidermal growth factor receptor expression in patients with advanced stage nasopharyngeal carcinoma treated with induction chemotherapy and radiotherapy

PURPOSE

A retrospective study was performed to correlate the expression of epidermal growth factor receptor (EGFR) with treatment outcome in advanced stage nasopharyngeal carcinoma (NPC).

METHODS AND MATERIALS

The study population comprised 54 of 92 patients with American Joint Committee on Cancer Stage III-IV NPC with sufficient pretreatment tumor biopsy specimens for study. Immunohistochemical staining was performed to evaluate the extent and intensity of EGFR expression. All patients were treated by induction chemotherapy with two to three cycles of cisplatin 60 mg/m(2) and epirubicin 110 mg/m(2) every 3 weeks followed by radiotherapy. The median follow-up time was 52 months for all patients and 99 months for surviving patients.

RESULTS

EGFR expression was present in 89% of cases. EGFR intensity was negative in 11%, weak in 43%, moderate in 13%, and strong in 33%. The EGFR extent was <5% in 15%, > or =5% but <25% in 13%, and > or =25% in 72%. No correlation was found between EGFR expression and T stage, N stage, stage group, nodal size, gender, and age. No statistically significant differences in chemotherapy response rates were found in patients with different EGFR intensity and extent. EGFR extent > or =25% was associated with a significantly poorer treatment outcome. The 5-year disease-specific survival, relapse-free survival, locoregional relapse-free, and distant metastasis-free rate in patients with EGFR extent > or =25% was 48%, 36%, 60%, and 55%, respectively. The corresponding rates in patients with EGFR extent <25% were 86%, 80%, 93%, and 86%. The differences were all statistically significant, except for distant metastasis. No statistically significant differences in relapse-free and disease-specific survival rates were found among patients with differing EGFR intensity. In multivariate analysis, EGFR extent was the only independent factor that predicted for disease relapse, locoregional failure, and cancer death.

CONCLUSION

Our study results showed that EGFR expression was common in advanced stage NPC, and the expression did not correlate with tumor or nodal stage. Correlative analysis showed that EGFR extent was a strong, independent prognostic factor that determined locoregional control, relapse-free survival, and disease-specific survival in Stage III-IV NPC treated with induction chemotherapy and radiotherapy. Our findings suggest that EGFR expression status can identify a subgroup of patients within advanced stage disease that will have a poor outcome after induction chemotherapy and radiotherapy. Whether this patient subgroup will benefit from an alternate treatment strategy and anti-EGFR-targeted treatment requires additional studies.

Amplificación del gen del receptor del factor de crecimiento epidérmico y expresión de la e-cadherina en los carcinomas de cabeza y cuello

INTRODUCTION

The E-cadherin adhesion molecule is fundamentally involved in the maintenance of normal epithelial morphology and differentiation. The scattering and invasion of cancer cells induced by epidermal growth factor receptor (EGFR) activation has been suggested to be probably by affecting E-cadherin function. The aim of this study is to confirm whether EGFR amplification is related to E-cadherin expression in head and neck squamous cell carcinomas.

MATERIAL AND METHODS

Fifty patients with head and neck squamous cell carcinoma were studied. EGFR amplification was analyzed by semiquantitative PCR. E-cadherin expressión was determined by immunohistochemistry.

RESULTS

EGFR amplification was found in 9 cases (18%). E-cadherin expression was generally weaker in tumors than in adjacent normal epithelium. No relationship was found between EGFR amplification and E-cadherin expression.

CONCLUSION

EGFR amplification did not affect the level of E-cadherin expression, suggesting a complementary role of both of these molecules in reduction of cellular adhesion in head and neck squamous cell carcinomas.

Prognostic significance of tumor angiogenesis, Ki 67, p53 oncoprotein, epidermal growth factor receptor and HER2 receptor protein expression in undifferentiated nasopharyngeal carcinoma--a prospective study

BACKGROUND

This study prospectively examines the prognostic role of p53 oncoprotein (p53), Ki67-antigen (Ki67), tumor angiogenesis (MVD), epidermal growth factor receptor (EGFR), and HER2 receptor protein (HER2) expression in Chinese with undifferentiated nasopharyngeal carcinoma (NPC).

METHODS

Seventy-eight Chinese were recruited from October 1995 to July 1997 at the Prince of Wales Hospital, Hong Kong. Pretreatment immunohistochemical preparations of the primary tumor were made, and clinical data were collected prospectively until October 30, 2000. The markers were correlated with overall survival (OS), disease-free survival (DFS), time to progression (TTP), and UICC stage.

RESULTS

On univariate analysis, EGFR expression correlated with poorer OS (p =.0001), DFS (p =.01), shorter TTP (p =.0001), and advanced T stage (p =.036). Strong EGFR expression, when compared with weak or moderate, was associated with poorer OS (p =.04) and shorter TTP in a subgroup of patients with UICC stage III-IV disease. HER2 expression was associated with advanced UICC stage (p =.006). The presence of p53 expression correlated with poorer DFS (p =.01) and a trend toward shorter TTP (p =.06). No correlation was found with Ki67-antigen or MVD. On multivariate analysis, only EGFR expression was significantly linked to shorter OS and TTP.

CONCLUSIONS

EGFR expression in undifferentiated NPC is associated with a poor clinical outcome. A prognostic role of p53 and HER2 expression is suggestive but not consistently defined in this study. The relatively high prevalence of positive staining for EGFR supports the use of molecular targeted therapy in this disease.

Pharmacological evaluation of humanized anti-epidermal growth factor receptor, monoclonal antibody h-R3, in patients with advanced epithelial-derived cancer

Epidermal growth factor receptor (EGFR) overexpression has been detected in many tumors of epithelial origin, and it is often associated with tumor growth advantages and poor prognosis. h-R3 is a genetically engineered humanized antibody (mAb) that recognizes an epitope located in the extracellular domain of human EGFR. The antibody exhibited potent in vitro and in vivo antitumor effect on EGFR overexpressing cell lines. To study safety, pharmacokinetics, and biodistribution, 12 patients with advanced epithelial-derived tumors received single intravenous infusion of h-R3 at four dose levels. Safety evaluation was made according to World Health Organization toxicity criteria. For biodistribution, 3 mg of the total dose were labeled with Technetium and then pooled with the rest of the dose. Anterior and posterior whole-body images were acquired using a gamma camera. Blood samples were taken for pharmacokinetics, antiidiotypic response, and for soluble EGFR detection. After hR3 administration, no evidence of severe toxicity was observed. Secondary reactions were mild and moderate and mainly consisted of tremors, fever, and vomiting. No anaphylactic or skin reactions were detected. Qualitative analysis of whole-body images showed that the liver had the highest mAb uptake. Pharmacokinetic analysis revealed that elimination half-lives and the AUC increased linearly with dose, while total body clearance decreased when increasing doses of h-R3. No relation between shed EGFR and mAb clearance was found. No antiidiotypic response against h-R3 was detected. Several phase II trials are now underway to evaluate the efficacy of h-R3 in the treatment of advanced cancer patients.

Expression of epidermal growth factor receptor in head and neck cancers correlates with clinical progression: a multicentre immunohistochemical study in the Asia-Pacific region

AIMS

With ongoing efforts to target the epidermal growth factor receptor (EGFR)-mediated tumour growth in the treatment of selected human malignancies, there is a need to determine the expression levels of EGFR and to evaluate its prognostic value in various malignancies in the Asia-Pacific region.

METHODS AND RESULTS

A total of 172 patients with head and neck squamous cell carcinomas from Australia, Hong Kong, Singapore, and Taiwan were selected for EGFR detection. Immunohistochemical staining was performed to evaluate EGFR expression. EGFR expression was present in 88.4% (152/172) of all cases tested. Specifically, EGFR expression was found in 91.3% (42/46), 84.6% (22/26), 84.1% (37/44), 96.0% (24/25), and 87.1% (27/31) cases of head and neck squamous cell carcinomas from the oral cavity, oropharynx, nasopharynx, hypopharynx, and larynx, respectively. The results demonstrate a stronger EGFR expression in T4 tumours (P=0.017) and later clinical stages (P=0.016). No significant correlation was seen with risk factors, primary tumour site and ethnicity.

CONCLUSIONS

The majority of head and neck squamous cell carcinomas express EGFR, indicating the importance of studying the efficacy of anti-cancer therapy through this pathway. The results also show similar rates of receptor expression in head and neck squamous cell carcinoma patients from our region compared with other parts of the world.

Absence of evidence for HER2 amplification in nasopharyngeal carcinoma

HER2 (c-erbB-2) has been suggested to be a prognostic factor in a variety of human cancers including breast, gastric and ovarian cancers. This study is therefore designed to identify changes of HER2 in nasopharyngeal carcinoma (NPC), an epithelia-derived malignancy with strong racial and geographic distribution. Interphase FISH and immunohistochemical (IHC) staining were used to analyze the gene copy number and protein expression of HER2 in 45 cases of NPC from Guangzhou, Southern China, an area with the highest incidence of NPC in the world. Our results, however, found no significant alterations in gene copy number for HER2, although IHC staining detected expression of HER2 oncoprotein in 33% of the 45 NPC tumors. No correlation was observed between HER2 expression and sex, age and clinical outcome of the patients, T stage, lymph node status, site and histopathological grading of the tumors. These results cast doubt on the value of HER2 as a prognostic factor for NPC.

Serum level and tissue expression of c-erbB-1 and c-erbB-2 proto-oncogene products in patients with squamous cell carcinoma of the head and neck

The proto-oncogene products erbB-l (EGF-Receptor) and erbB-2 (HER-2/neu), distinct members of the epidermal growth factor receptor family, are frequently overexpressed in squamous cell carcinoma of the head and neck (SCCHN). The accumulation of these transmembrane proteins may lead to significant amounts of the respective extracellular receptor domains (ECD) that are shed from the tumour cell surface and enter blood circulation, thus representing potential serum tumour markers. For erbB-l and erbB-2, we determined the ECD serum levels with enzyme-linked immunosorbent assays and evaluated the protein expression in tumour tissue by immunohistochemistry. The present study included 49 patients (37 untreated, 12 recurrences) and the same number of age- and sex-matched healthy controls. In 24 patients ECD serum levels were determined before and 6 weeks after surgery. Mean ECD serum levels for erbB-1 and erbB-2 were 54.8+/-1.6 and 153.7+/-6.1 fmol/ml in cancer patients, and 54+/-1.5 and 147.9+/-4.5 fmol/ml in healthy controls, respectively. There was no significant difference between untreated and recurrent disease. Serum ECD follow-ups 6 weeks after surgery revealed a significant 12.3% decline of erbB-1 but no change of erbB-2 values. Immunohistochemistry showed strong staining for erbB-1 in 78% and erbB-2 in 47% of the SCCHN specimens. No correlation was detectable between receptor ECD serum levels and receptor tissue expression, tumour stage, and tumour differentiation. Hence, ECD serum levels of erbB-1 and erbB-2 are not considered to be valuable tumour markers in SCCHN.

Differential modulation of proliferation, matrix metalloproteinase expression and invasion of human head and neck squamous carcinoma cells by c-erbB ligands

Evidence suggests that there is an association between the abnormal expression of members of the c-erbB receptor tyrosine kinase family and poor prognosis in head and neck squamous cell carcinomas (HNSCC). Until now, the relative contributions of different c-erbB ligands to HNSCC progression have not been clearly defined. In this paper we examined the effects of ligands with different c-erbB receptor specificities in terms of their stimulation of HNSCC proliferation, expression of matrix metalloproteinases (MMPs) and invasion. Heregulin-beta1 (HRG-beta1; selective c-erbB3/B4 ligand) was found to stimulate proliferation in the majority of cell lines, whereas epidermal growth factor (EGF; EGFR ligand) and betacellulin (BTC; EGFR/B4 ligand) induced variable responses. All three ligands up-regulated multiple MMPs including collagenases, stromelysins, matrilysin and gelatinase B (MMP-9) but had minimal or no effects on gelatinase A (MMP-2), MT1-MMP and tissue inhibitors of MMPs (TIMPs). MMP-9 mRNA was induced to a higher level than other MMPs, although with slower kinetics. HRG-beta1 was less active than EGF and BTC at the optimal concentration (relative potency of EGF:BTC:HRG = 3:4:1). In vitro invasion through Matrigel was also increased by all three ligands in proportion to their MMP up-regulation. A specific anti-EGFR monoclonal antibody (mAb ICR62) inhibited MMP up-regulation, migration and invasion induced by all three ligands, whereas an anti-c-erbB-2 mAb ICR12 inhibited mitogenic and motogenic responses following ligand stimulation but had no effect on MMP expression. These results suggest that c-erbB ligands may differentially potentiate the invasive phenotype of HNSCC via co-operative induction of cell proliferation, migration and proteolysis. The EGFR signalling pathway appears to be the dominant component controlling the proteolytic and invasive phenotype in HNSCC, whereas the c-erbB-2 signalling pathway is responsible, in part, for the mitogenic and motogenic effects of ligands.

c-erbB-2 gene amplification in nasopharyngeal carcinoma

Amplification of the c-erbB-2 gene has been associated with poor prognosis in different types of cancer. However, there are no data on the c-erbB-2 expression levels in nasopharyngeal cancer. In this study, amplification of the gene has been investigated in the tumor tissue of patients with nasopharyngeal cancer by competitive polymerase chain reaction c-erbB-2 amplification was observed in 43.3% of the patients. The increase in the gene copy number correlated with the T stage. No correlation was found with lymph node involvement, histologic grade, differentiation, presence of metastases, or age and sex. We conclude that c-erbB-2 amplification may contribute to the pathogenesis of nasopharyngeal cancer. Our report is the first study investigating the expression of the c-erbB-2 gene in nasopharyngeal cancer at the DNA level.

Prognostic implications of epidermal growth factor receptor immunoreactivity in squamous cell carcinoma of the oral mucosa

To evaluate the clinical significance of the expression of epidermal growth factor receptor (EGFr) in oral squamous cell carcinoma (SCC), 100 formalin-fixed, paraffin-embedded cases of this tumour and ten samples of normal oral mucosa were immunostained with a monoclonal anti-EGFr antibody using an immunoalkaline phosphatase (APAAP) technique. EGFr immunoreactivity was detected in 36 of 100 tumours and in all samples of normal mucosa. Tumour cells demonstrated distinct membrane staining in 14 cases and predominantly cytoplasmic staining in 22 additional cases. EGFr was exclusively localized on the cell membrane of normal epithelial cells. Kaplan-Meyer survival curves and Cox proportional hazard regression models were used to assess overall survival and disease-free survival. A significant positive correlation was shown between EGFr membranous immunoreactivity and prolonged survival, in both univariate and multivariate analyses. Accordingly, patients with oral SCC showing down-regulated expression of membranous EGFr, who are more likely to suffer recurrence and death, should be strictly followed up and possibly treated with more aggressive therapeutic regimens.

Epidermal growth factor receptor, c-erbB-2 and p53 overexpressions in epithelial hyperplastic lesions of the larynx

An immunohistochemical analysis of overexpression of epidermal growth factor receptor (EGFR), c-erbB-2, and p53 proteins was performed on 43 biopsies of laryngeal epithelial hyperplastic lesions (EHLL), classified according to the Kambic-Lenart classification, and in 11 cases of laryngeal carcinoma (SCCL). The aim of the present study was to determine whether there is a correlation between the staining patterns of these proteins and different grades of EHLL, and to reveal their possible prognostic value. We compared the staining patterns of atypical hyperplasia adjacent to cancer with the same type of lesions which have not turned malignant. p53 and EGFR overexpressions were detected in 28/54 (52%) and 33/54 cases (61%), respectively, and tend to increase with the degree of epithelial changes. The intensity of staining in various grades of EHLL adjacent to cancer was more pronounced than the same type of lesions which have not progressed to cancer. c-erbB-2 was weakly positive in the majority of cases, and changed from predominantly membranous in simple hyperplasia to cytoplasmic staining in abnormal and atypical hyperplasias. There was no significant statistic correlation between the amount of positive cells for all proteins and the grade of epithelial abnormalities. We conclude that the overexpression of each biomarker itself adds little predictive value over routine histomorphology, and cannot be regarded as a reliable prognostic factor for EHLL. However, the histologic characteristics of atypical hyperplasia together with the immunostaining patterns of EGFR and p53 up to two-thirds or more of the epithelial thickness could be considered a reliable pattern which correlates with the progression to cancer.

Amplification of ERBB oncogenes in squamous cell carcinomas of the head and neck

The activation of ERBB oncogenes has been described in various human tumours, including squamous cell carcinomas of the head and neck (SCCHN), and, in some of them, it has been correlated with a poor prognosis. Tissue samples from 59 patients with SCCHN were studied. After DNA extraction, the ERBB1, ERBB2 and ERBB3 copy number in tumour samples was estimated with the polymerase chain reaction (PCR) method. The PCR products were analysed by agarose gel electrophoresis and quantified by image analysis techniques. 9 (15%) cases presented with ERBB1 amplification, which was correlated with lymph node involvement (P = 0.04), poorly differentiated tumours (P = 0.03) and a hypopharyngeal primary site (P = 0.035). No correlation among amplification status, recurrence, metastases and survival was observed, although this may be due to the small number of patients in the amplified group. None of the 59 cases presented amplification of ERBB2 and ERBB3 oncogenes.

A sensitive enzyme-linked immunosorbent assay used for quantitation of epidermal growth factor receptor protein in head and neck carcinomas: evaluation, interpretations and limitations

The EGF receptor is a transmembrane glycoprotein exerting mitogenic effects on epithelial cells. The purpose of the present study was to develop a sensitive enzyme-linked immunosorbent assay (ELISA) for determination of the epidermal growth factor receptor (EGFR) protein to examine whether the receptor was overexpressed in head and neck squamous cell carcinomas compared with the normal counterpart, and to establish whether clinicopathological correlations were present by investigating a broad spectrum of parameters (tumour size, clinical stage, positive lymph nodes, tumour site, histological grade, keratinisation, preoperative irradiation and clinical outcome). The assay employs two commercially available monoclonal antibodies, both detecting protein epitopes. The material comprises 60 head and neck carcinomas, corresponding normal tissue and normal oral mucosa from healthy individuals. The study demonstrates significantly higher receptor levels in tumours compared with normal tissue (P < 0.002) and a range in tumours and normal tissues of 0.4-10.5 and 0.1-4.3 nmol g-1 membrane protein respectively. Quantitation of receptors in normal mucosa emphasises the importance of using the patients' corresponding normal tissue, because using the patients' mucosa resulted in 83% overexpression, while using normal mucosa from healthy individuals only demonstrated overexpression in 50% of cases. No significant clinicopathological correlations could be established, although the mean values for EGFR increased with tumour size and advanced clinical stage. Furthermore, the prognostic value concerning disease-free survival, recurrence and the time interval for recurrence were investigated but no significance could be demonstrated. In conclusion, the investigation supports the theory of overexpression of EGFR protein as a common motif for malignant epithelial tumours, but limitations in interpretations are demonstrated and discussed further.

Tyrosine phosphorylation as a marker for aberrantly regulated growth-promoting pathways in cell lines derived from head and neck malignancies

We have utilized a broad approach to address whether tyrosine kinases and the growth pathways they regulate might be functionally aberrant in squamous cell carcinomas (SCC) of the upper aerodigestive tract. This strategy involved assaying for evidence of tyrosine kinase action in lysates of cell lines representing SCC. Our findings revealed a spectrum of elevated tyrosine phosphorylation in SCC lines ranging from less than 2-fold to more than 10-fold above that of control human epidermal keratinocytes. Thus the ability to regulate growth and other pathways controlled by tyrosine phosphorylation was impaired in all the 19 lines examined. Assessment of the receptor for epidermal growth factor (EGF) revealed that its activity was elevated above normal in 14 of the 19 cell lines examined, suggesting that at least a portion of the increased tyrosine phosphorylation observed could be attributed to excessive EGF receptor activity. Our findings provide functional evidence that growth pathways are aberrantly regulated in cell lines representing SCC of the upper aerodigestive tract.

Prognostic utility of epidermal growth factor receptor overexpression in endometrial adenocarcinoma

BACKGROUND

Overexpression of epidermal growth factor receptor (EGFR) has been reported in endometrial adenocarcinoma.

METHODS

A retrospective analytic study was designed to investigate its prognostic utility. Sixty-nine patients were studied with cell types that included endometrioid (n = 45), papillary serous (n = 16), and clear cell (n = 8). Patients' medical charts and survival data were reviewed. Assessment of EGFR overexpression was done at the protein level by the use of an anti-EGFR polyclonal antibody that reacts with the cytoplasmic membrane glycoprotein receptor in paraffin-embedded tissues.

RESULTS

EGFR was overexpressed in 34 (49%) patients in whom immunoreactivity was limited to neoplastic cells. Initial bivariate analysis revealed significant correlations between EGFR immunoreactivity and histologic grade (r = 0.44, P < 0.001), metastasis (r = 0.38, P < 0.001), cell type (r = 0.30, P < 0.01), myometrial invasion (r = 0.30, P < 0.01), and patient age (r = 0.30, P < 0.01). Multiple logistic regression analyses showed that EGFR overexpression and nonendometrioid cell types are two independent statistically significant markers for the presence of metastases. EGFR immunoreactivity can significantly predict myometrial invasion, but after controlling for the histologic grade, its ability of significantly predict invasion was lost. EGFR overexpression was shown to be a statistically significant predictor of survival, even after controlling for patient age, histologic grade, and cell type.

CONCLUSIONS

Expression of this oncoprotein may serve as an independent prognostic indicator and a guide to therapy in patients with endometrial cancer.

Molecular lesions in human oral cancer: the Indian scene

Carcinogenesis is a multi-step process including aberrant expression of two interacting classes of genes--oncogenes and tumour suppressor genes. With recent technological advances, it is feasible to identify the various molecular lesions underlying the different stages of neoplasia. Squamous cell carcinomas of the head and neck, although representing 2-4% of the malignancies in the West, comprise a large fraction (40%) of total cancers in India, posing a major health problem. Further, epidemiological and experimental evidence unequivocally confirms a causal association between tobacco chewing habit, highly prevalent in India, and oral cancers. Thus, the oral cancers offer an excellent in vivo system for the study of the environmental tobacco-carcinogen induced molecular alterations in the malignancy, and associated premalignant lesions such as leukoplakia. With a view to elucidating the molecular lesions involving oncogenes in oral carcinogenesis, we have investigated myc/ras/EGF-R activation by amplification, point mutation, gene rearrangement and allelic losses. Further, a functionally activated potent transforming gene was detected in a NIH3T3 transfection/tumorigenicity assay, unrelated to myc/ras/EGF-R. Studies on the involvement of p53 gene in oral cancer, indicates p53 allelic loss as an event observed in leukoplakia and tumour tissues. Advanced oral cancer stages demonstrate cumulative molecular aberrations, with greater than 95% samples showing oncogene involvement, thus indicating a multi-step process of oral carcinogenesis. The review presents a comparative picture of the oral malignancies seen in Western countries and India, significance of molecular lesions and future perspectives of oncogenes and tumour suppressor gene involvement in oral cancer.