Detection of K-ras gene mutation in tumour tissue in metastatic colorectal carcinomas by RT-PCR And DNA sequence analysis and its association with clinical parameters

The predictive factor in determining the patients who will respond to Anti-EGFR (epidermal growth factor receptor) treatments is K-ras gene mutation. This mutation is of great importance in terms of showing its existence, prognosis of patients and respond of molecular targeted therapies. This study aimed to detect mutations by RT-PCR and DNA sequence analysis, and to assess associations with clinicopathological parameters.40 Metastatic Colorectal Cancer patients were included in the study. With DNA sequence analysis, K-ras gene mutation was detected in codon 12 and codon 13 in 11 and 2 patients, respectively. Also, with RT-PCR method, this mutation was detected in codon 12 in 8 patients. When the cases with or without mutation were compared with RT-PCR and DNA sequence analysis, there was not a statistically significant correlation between them (p=0.505, p=0.906). It was seen that the existence of K-ras gene mutation did not statistically influence general survival (p=0.564, p=0.536). The association between cases in which mutation was detected and various clinicopathological parameters was assessed and a significant association was not detected.In conclusion, that the detected mutations are the most frequently encountered ones, and there?s a congruence of 72% between the results obtained by RT-PCR and DNA sequence analysis (which are mutation scanning methods) reveal the precision of the study. In order to introduce the existence of K-ras gene mutation, researches in broader study groups should be carried out on clinicopathological parameters.