P-225 KRAS codon 12 and 13 mutations in metastatic colorectal cancer: Predictive marker in first-line bevacizumab-based chemotherapy

Abstract

The three human RAS genes (KRAS, NRAS, and HRAS) are the most frequently mutated oncogenes and present in 45% of patients with colorectal cancer, being known as an early event in tumorigenesis. Most KRAS mutations (90%) occur in codons 12 and 13 of exon 2. However, the role of different KRAS mutations and its prognostic value remains controversial, with few studies showing a worse progression-free survival and overall survival with codon 12 KRAS mutation. The aim of our study was to evaluate KRAS codon mutation (codon 12 and 13) as a predictive marker of first-line bevacizumab-based chemotherapy response.