Molecular Biomarker KRAS as Superior Predictor of Overall Survival in Patient with Resectable Colorectal Liver Metastases

Introduction: This study pursues to investigate the prognostic value of different risk factors associated with the primary colorectal tumor in patients with resected colorectal liver metastases (CRLM). Methods: All patients who underwent resection of CRLM with curative intent from January 2010 to August 2018 were included. The relationship between overall survival (OS) and six clinicopathologic variables related to the primary colorectal tumor, such as tumor location, T4 status, lymph node positiveness, lymphovascular invasion (LVI), perineural invasion (PNI), extrahepatic disease, and KRAS status (mutated vs wild type) were analyzed. Univariate analysis was performed with Kaplan-Meier and the log-rank test. For multivariate analysis, Cox proportional hazard regression model was used. Results: Data were available for 129 patients. Univariate analysis identified extrahepatic disease, mt-Kras, and lymph node positiveness of the primary colorectal tumor as adverse prognostic factors for OS after hepatic resection. In multivariate analysis, extrahepatic disease [HR of 3.89 95% IC 1.33-11.37(p=0.013)] and mt-Kras [HR of 2.59 95%IC 1.46-4.58 (p=0.001)] were independently associated with significantly shorter OS. Conclusions: In the last years, a bunch of risk scores with different clinicopathologic characteristics have been evaluated as survival prognostic factors, but their feasibility is not totally widespread. Our study shows how a molecular biomarker as mt-Kras, is an indicator of a worse outcome for patients with resectable colorectal liver metastases.