Preoperative Serum Axl/Gas6 Allow Stratification of Oncological Outcome in Patients Undergoing Liver Resection for Hepatocellular Carcinoma

Abstract

Introduction: Liver resection is routinely performed in patients suffering from primary liver malignancies. Still, this group of neoplastic entities is known to have an unfavourable prognosis. Thus, preoperative risk assessment is vital for clinical decision making. Recently, Axl and its ligand Gas6 were found to be associated to unfavourable tumor characteristics in hepatocellular carcinoma (HCC). Further, a negative correlation with overall survival (OS) and disease-free survival (DFS) were observed, which suggests its potential use as a prognostic marker in HCC patients. Method: Serum was collected in 27 patients prior to liver resection for HCC. Levels of Axl/Gas6 were measured via ELISA and evaluated as markers for OS and DFS. Results: Indeed, Axl and Gas6 were elevated in patients with an OS of less than one year and showed a high predictive potential for death within this period as assessed via receiver operating characteristics (p=0.033,AUC=0.809, respectively). Using the Youden index, optimal cut-offs were identified at 45.00 ng/mL for Axl and at 50.00 ng/mL for Gas6. Interestingly, patients above the cut-off for Axl showed significantly reduced OS in Kaplan-Meier analysis (p=0.045), and a tendency towards earlier tumor recurrence (p=0.067). Similarly, patients with increased Gas6 levels tended to display reduced OS (p=0.072), while there was no association to DFS. Conclusion: The present data underlines a potential benefit of incorporation of Axl/Gas6 in clinical routine. Especially combination with other biological markers could further increase validity. Accordingly, clinical decision making and treatment evaluation could be adapted in concordance with these markers.