Prognostic factors of survival in stage IV colorectal cancer with synchronous liver metastasis: Negative effect of the KRAS mutation

The aim of the present study was to identify predictive parameters of survival in patients affected by stage IV colorectal cancer with synchronous and bilateral liver metastases. A retrospective cohort study was performed. Patients diagnosed between January 2013 and December 2018 were included in the present study. Data on the histopathological, clinical and treatment factors (chemotherapy as the first measure or resection of the primary tumor) were collected. The effect of each variable on survival was evaluated using Cox regression analysis. A total of 104 patients were included [43 women (41.3%) and 61 men (58.7%); mean age, 63 years]. The long-term survival rate at 36 months was 29% (median, 25 months). Kaplan-Meier analysis was used to estimate that survival was higher in patients with wild-type KRAS tumors (42%) than in patients with mutated KRAS tumors (9%; P=0.001). In the multivariate analysis, KRAS mutation (HR, 2.484; 95% CI, 1.472-4.192), T4 tumors (HR, 1.795; 95% CI, 1.045-3.084), resection/local treatment of hepatic metastases (HR, 0.447; 95% CI, 0.222-0.901), Eastern Cooperative Oncology Group performance status (HR, 1.632; 95% CI, 1.182-2.254), were revealed to have independent predictive value. The type of treatment (chemotherapy or resection of the primary tumor) did not influence the survival. The results indicated that mutation of the KRAS gene was an important prognostic factor and associated with survival.