Associations of positive epidermal growth factor receptor expression and K-RAS gene mutations with various clinicopathological parameters and survival of colorectal carcinoma patients

Abstract

Epidermal growth factor receptor (EGFR) is a member of the transmembrane receptor tyrosine kinase family. In normal and malignant cells, activation of the EGFR cascade is involved in the regulation of various cellular activities. The objective of this study was to identify and assess associations of positive EGFR expression and K-RAS mutations with various clinicopathological parameters and survival of colorectal carcinoma patients. EGFR of colorectal cancer (CRC) tissue specimens was subjected to immunohistochemical analysis, polymerase chain reaction, and DNA sequencing. Immunohistochemical staining was performed using monoclonal antibodies against EGFR antigens and examination of mutations was performed to detect mutations in codons 12 and 13 of the K-RAS. Statistical analysis was performed using SPSS version 16.0. The results of this study showed that of the 40 study participants, 62.5% (25/40) showed positive EGFR overexpression. Of the patients showing positive EGFR expressions, 52% had mutations in the K-RAS. Mutations were spread in codon 12 (64.3%) and codon 13 (35.7%) and there was one sample with mutations in codons 12 and 13 at the same time. A statistically significant association was found between the presence of metastasis and EGFR overexpression and survival of CRC patients. In addition, a significant association was found between K-RAS mutations and metastasis and survival of CRC patients. In conclusion, EGFR overexpression and K-RAS mutations were found in CRC patients. Both factors are known to be associated with poor prognosis of cancer patients in terms of patient survival. Early detection of K-RAS mutations in CRC patients is a crucial component in the determination of the type of therapy and treatment for the patient.