KRAS and cancer: Our analysis showed that KRAS mutation detected by cfDNA was associated with a poorer survival in cancer patients for OS and PFS (HR = 2.02, 95% CI 1.63–2.51, P<0.01 and HR = 1.64, 95% CI 1.27–2.13, P<0.01, respectively) (Figs 2 and 3).