The value of AXL expression in squamous cell carcinoma of the lung: relationship with clinicopathological parameters

Introduction: The AXL receptor tyrosine kinase (AXL) plays a central role in tumor proliferation, carcinogenesis and progression. The aim of the present study was to evaluate the expression of AXL in cell block specimens from 40 surgically resected squamous cell carcinomas of the lung (SCCL). Methods: Expression of AXL in cancer specimens was examined by immunocytochemical method and the results correlated with clinicopathologic features. Results: The immunoreactivity of AXL was low in normal epithelium and increased positive percentage was noted from normal hyperplastic epithelium (9,2%) to cancer (55,6%). AXL expression correlated with lymphnode status (p=0,01), differentiation (p<0,001) and clinical stage (p=0,016) of SCCL. Patients with high expression of AXL showed poor prognosis compared with those with low AXL expression patients (p<0,001). In multivariable analysis (cox regression model) AXL expression remained as an independent prognostic factor (p=0,035). Conclusions: Our results indicated that AXL promotes the carcinogenesis and progression of SCCL and is a valuable marker for aggressiveness of SCCL.