Prognostic and predictive importance of EGFR expression and K-ras mutations in gastric cancer

Epidermal growth factor receptor (EGFR), a member of the tyrosine kinase family in general, is thought to be responsible for cell proliferation and for carcinogenesis. Signal transitions in the regulation of plasma membrane serves as a member of the RAS gene family of K-ras proto-oncogenes play an important role carcinogenesis through point mutations. K-ras mutations in pancreatic, lung, colon and stomach cancer is common. K-ras mutations at codon 12 and 13 mostly, rarely occurs at codon 61.In this study, EGFR expression in gastric cancer patients and their prognostic and predictive importance of K-ras mutations were investigated. Working group between the years 1995 to 2008 Çağlayan Florence Nightingale Hospital Medical Oncology and Istanbul University Faculty of Medicine, Department of Pathology and treated in the follow-up, paraffin blocks and slides may have consisted of 62 gastric cancer patients. 62 patients were included in paraffin embedded sections from gastric tissue of patients with EGFR expression and the immunohistochemistry method (-) and (+) those determined. EGFR positive patients, DNA obtained from paraffin embedded tissue samples and K-ras oncogenes were isolated mutations in codons 12 and 13 points to the existence of the mutagenic polymerase chain reaction (mutagenic PCR) and restriction fragment length polymorphism (RFLP) method was evaluated.EGFR expression in 62 gastric cancer patients (+) the 48 (77.42%) patients of the K-ras gene codon 12 GG, GC and CC genotype frequencies were: 93.62%, 6.38% and 0% K -ras gene codon 13 of the CC, CG, GG genotype frequencies were: 74.07%, 25.93% and 0% respectively.Cetuximab is a monoclonal antibody, K-ras wild type first-line treatment of colorectal cancer patients has become a new treatment option. In previous studies, K-ras polymorphism in patients with the wild type allele of the drug Cetuximab and respond well to prevent proliferation are aware that our patients in our group are also higher on these genotypes. This type of polymorphism studies in cancer drug therapy, especially in individuals believe would benefit.