The influence of KRAS and BRAF mutations on the efficacy of cetuximab-based first-line therapy of metastatic colorectal cancer: an analysis of the AIO KRK-0104-trial

Abstract

Our study investigated the impact of specific KRAS mutations and BRAF mutation on progression-free survival (PFS) and overall survival (OS) in patients with metastatic colorectal cancer (mCRC) treated within the AIO KRK-0104-trial as first-line therapy. In total, 146 (of 185) patients were included in this analysis. Seventy-nine patients presented with KRAS/BRAF wild-type (wt), 41 patients with a KRAS codon 12 and nine patients with a KRAS codon 13 mutation. Seventeen patients presented a BRAF-mutated tumor. The patients of our study were treated with CAPIRI/CAPOX plus cetuximab. Major differences regarding PFS and OS were observed depending on the mutation of the tumor. PFS was 8 months in patients with wt-tumors, 5.8 months with codon 12-mutated, 9.9 months with codon 13-mutated and 4.2 months with BRAF-mutated tumors. OS was 23.5 months in patients with wt-tumors, 18.9 months with codon 12-mutated, 26.2 months with codon 13-mutated and 13.0 months with BRAF-mutated tumors. Although the conventional separation of patients with KRAS wild-type versus KRAS mutant tumors did not have a significant impact on outcome parameters in the AIO KRK 0104-trial, this analysis demonstrates that markedly differing results are obtained when subtypes of KRAS and BRAF mutation are taken into account.