KRAS and neoplasm: In patients with synchronous metastases, the OS of patients with wild-type KRAS was significantly better than those with mutant KRAS. Multivariate analyses indicated shorter OS to be independently associated with positive primary lymph node, and large tumor size and R1 resection in patients with metachronous metastasis, whereas to be independently associated with mutant KRAS status in patients with synchronous metastasis.