Alterations in epidermal growth factor receptors 1 and 2 in esophageal squamous cell carcinomas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Background: Esophageal squamous cell carcinoma (ESCC) shows a 5-year survival rate below 10%, demonstrating the urgency in improving its treatment. Alterations in epidermal growth factor receptors are closely related to malignancy transformation in a number of tumors and recent successful targeted therapies have been directed to these molecules. Therefore, in this study, we analyzed the expression of EGFR and HER2 and evaluated EGFR mutation profile as well as the presence of mutations in hotspots of KRAS and BRAF in ESCC patients. Methods: We performed RT-qPCR, immunohistochemistry and Fluorescent in situ hybridization to determine EGFR and HER2 expression in ESCC patients, and direct sequencing and PCR-RFLP for mutations and polymorphism analysis. Results: Our results showed an increased EGFR mRNA expression in tumors compared to surrounding tissue (p T) in 2.1% of the patients, and at codon 787 (G>A) in 79.2% of the cases. This last polymorphism was also evaluated in 304 healthy controls, which presented a similar frequency (73.7%) in comparison with ESCC patients. The absence of mutations of EGFR, KRAS and BRAF as well as the overexpression of EGFR and HER2 in less than 10% of the patients suggest that this signaling pathway is altered in only a small proportion of patients with ESCC. Conclusion: HER receptors target therapies may have the potential to be effective in only a minor fraction of patients with ESCC.12Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq