EGFR gene copy number alteration is a better prognostic indicator than protein overexpression in oral tongue squamous cell carcinomas

Maxillofacial Surgery, Maxillofacial Reconstruction and Function, Division of Maxillofacial and Neck Reconstruction, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
European journal of cancer (Oxford, England: 1990) (Impact Factor: 5.42). 08/2011; 47(15):2364-72. DOI: 10.1016/j.ejca.2011.07.006
Source: PubMed


Although epidermal growth factor receptor (EGFR) is particularly important in the pathogenesis of head and neck squamous cell carcinomas (HNSCCs), conflicting data have been reported on the correlation between EGFR copy number and survival and the association between EGFR copy number and protein expression. Anatomical site of the tumour in HNSCCs may likely contribute to the discordance of the above points as EGFR expression may differ between the sub-sites of HNSCCs. Thus, in this study, we focused on oral tongue squamous cell carcinomas (OTSCCs). To investigate the association between EGFR copy number alteration and overexpression and to determine which is the more reliable prognostic indicator, Fluorescence in situ hybridisation (FISH) and immunohistochemical staining (IHC) were performed at a single institution on samples from 89 patients with OTSCCs undergoing surgery as the primary treatment modality. Thirty-two (36%) of 89 cases demonstrated an EGFR copy number alteration. EGFR protein expression was found in all 89 cases, of which 82.0% showed overexpression. No significant correlation was found between gene copy number and protein overexpression. Gene copy number alteration was significantly associated with reduced disease-free survival (P=0.048) and overall survival (P=0.001). Multivariate Cox proportional hazards analysis demonstrated that EGFR copy number increase was significantly correlated with overall survival (P=0.001). EGFR copy number status is a more reliable indicator than protein overexpression of the survival rate in OTSCCs. FISH analysis of the EGFR status is useful in predicting poor prognosis in OTSCCs.

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    • "Using the criteria described in the Methods section, 49.1% of these specimens were negative for PTEN expression, and 86.9% were positive for pAKT expression. With regard to EGFRwt, 63.9% of the samples were positive for the membranous expression of the wild-type protein [25]. Conversely, moderate to strong levels of EGFRvIII staining were present in the cytoplasm of 75% of the samples. "
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    ABSTRACT: Dysregulated epidermal growth factor receptor (EGFR)-phosphoinositide-3-kinase (PI3K)-AKT signaling is considered pivotal for oral cancer, and the pathway is a potential candidate for therapeutic targeting. A total of 108 archival samples which were from surgically resected oral cancer were examined. Immunohistochemical staining showed the protein expression of membranous wild-type EGFR and cytoplasmic phosphorylated AKT was detected in 63.9% and 86.9% of the specimens, respectively. In 49.1% of the samples, no phosphatase and tensin homolog (PTEN) expression was detected. With regard to the EGFR variant III (EGFRvIII), 75.0% of the samples showed positive expression for moderate to severe staining, 31.5% of which had high expression levels. Real-time polymerase chain reaction assays for gene copy number assessment of PIK3CA revealed that 24.8% of the samples had alterations, and of EGFR showed that 49.0% had amplification. Direct sequencing of PIK3CA gene showed 2.3% of the samples had a hotspot point mutation. Statistical assessment showed the expression of the EGFRvIII correlated with the T classification and TNM stage. The Kaplan-Meier analyses for patient survival showed that the individual status of phosphorylated AKT and EGFRvIII led to significant differences in survival outcome. The multivariate analysis indicated that phosphorylated AKT, EGFRvIII expression and disease stage were patient survival determinants. Aberrations in the EGFR-PI3K-AKT pathway were frequently found in oral cancers. EGFRvIII and phosphorylated AKT were predictors for the patient survival and clinical outcome.
    Full-text · Article · Jun 2013 · Journal of Biomedical Science
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    ABSTRACT: Head and Neck Squamous Cell Carcinomas (HNSCC) are the 6th most common cancers worldwide. While incidence rates for cancer of the hypopharynx and larynx are decreasing, a significant increase in cancer of the oropharynx (OSCC) is observed. Classical risk factors for HNSCC are smoking and alcohol. It has been shown for 25 to 60% of OSCC to be associated with an infection by oncogenic human papilloma viruses (HPV). The development of “common” cancer of the head and neck is substantially enhanced by an accumulation of genetic changes, which lead to an inactivation of tumor suppressor genes or activation of proto-oncogenes. A more or less uniform sequence of different DNA-damages leads to genetic instability. In this context, an early and frequent event is deletion on the short arm of chromosome 9, which results in inactivation of the p16-gene. In contrast, for HPV-induced carcinogenesis, expression of the viral proteins E6 and E7 is most important, since they lead to inactivation of the cellular tumor-suppressor-proteins p53 and Rb. The natural route of transoral infection is a matter of debate; peroral HPV-infections might be frequent and disappear uneventfully in most cases. Smoking seems to increase the probability for developing an HPV-associated OSCC. The association of HNSCC with HPV can be proven with established methods in clinical diagnostics. In addition to classical prognostic factors, diagnosis of HPV-association may become important for selection of future therapies. Prognostic relevance of HPV probably surmounts many known risk-factors, for example regional metastasis. Until now, no other molecular markers are established in clinical routine. Future therapy concepts may vary for the two subgroups of patients, particularly patients with HPV-associated OSCC may take advantage of less aggressive treatments. Finally, an outlook will be given on possible targeted therapies.
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    ABSTRACT: The aim of this study was to evaluate the impact of expression of epidermal growth factor receptor (EGFR), mesenchymal-epithelial transition factor (c-Met), and insulin-like growth factor receptor 1 (IGF-1R) protein on response to treatment and survival in patients with oral and oropharyngeal squamous cell carcinoma (SCC). EGFR, c-Met, and IGF-1R immunohistochemical (IHC) scores were generated based on the incidence and intensity of expression of the biomarkers evaluated in paraffin-embedded sections of biopsy specimens taken before treatment from 113 patients given neoadjuvant chemoradiotherapy followed by resection for primary locally advanced oral and oropharyngeal SCC. Correlations were assessed between the IHC of the biomarkers and the patients' clinicopathological variables using Spearman's rank test. Cox's regression models were used to evaluate the impact of EGFR, c-Met, and IGF-1R, expression on survival. Almost all the patients showed expression of EGFR, c-Met, and IGF-1R (99%, 100%, and 100%, respectively). None of the biomarkers examined predicted response to neoadjuvant chemoradiotherapy or were associated with survival. In multivariate analysis, age (p=0.05), alcohol consumption (p=0.03), and pathological size/extent of the primary tumour after neoadjuvant treatment (ypT) status (p=0.009) were significantly associated with recurrence-free survival. Age (p=0.02) and alcohol consumption (p=0.02) were independently associated with overall survival. Although none of the biomarkers evaluated could be used as prognostic indicators, their common expression suggested a strong rationale for targeting EGFR, c-Met, and IGF-1R in the treatment of oral and oropharyngeal SCC.
    No preview · Article · Aug 2012 · British Journal of Oral and Maxillofacial Surgery
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