Not All Kirsten Rat Sarcoma Viral Oncogene Homolog Mutations Predict Poor Survival in Patients With Unresectable Colorectal Liver Metastasis.

Objective: To assess the characteristics of Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations and investigated whether all KRAS mutations predict poor prognosis in patients with unresectable colorectal liver metastasis (CRLM).

Methods: Correlations between KRAS-mutation status and clinicopathological characteristics of 93 patients with unresectable CRLM at our institution between 2010 and 2018 were retrospectively analyzed. Kaplan-Meier and Cox proportional hazard models were used to evaluate the prognostic significance of KRAS mutations.

Results: KRAS were primarily single-point mutations, identified in 41.9% of patients. There were no significant differences in clinicopathological characteristics between wild-type KRAS and mutant KRAS. Patients with mutant KRAS had significantly worse overall survival (OS) and progression-free survival (PFS) than those with wild-type KRAS. Moreover, patients with codon 12 mutations had worse OS and PFS than those with wild-type KRAS, whereas mutations in codon 13 were not associated with a worse prognosis. Among the 5 most common mutations in codons 12, G12V, and G12D were associated with worse OS, furthermore, G12C mutation seemed to associated with worse PFS than patients with wild-type KRAS.

Conclusion: KRAS codon 12 mutations were predictive for a poor prognosis in patients with unresectable CRLM. G12D and G12V mutations were associated with worse OS, whereas G12C mutation seemed to be associated with decreased PFS.