SMAD4 and neoplasm: Through multivariable analysis (Table 4), high mutation abundances of KRAS in both tumor (P = 0.007) and blood (P < 0.001), and high mutation abundance of TP53 (P = 0.033) and SMAD4 (P = 0.015) in ctDNA were significantly and independently associated with poorer OS, and high mutation abundance of CDKN2A (P = 0.018) and SMAD4 (P = 0.020) in ctDNA were significantly and independently associated with poorer PFS.