KRAS and neoplasm: The univariate analysis showed that K-ras mutations and treatment choice were associated with poor prognosis in CRC patients (p = 0.017 and, p = 0.047, respectively), while the multivariate analysis showed that, K-ras mutation, treatment choice, and poor tumor differentiation were independent factors for survival of patients with mCRC (p = 0.004, p = 0.006 and p = 0.015, respectively; Table 4).