Overexpression of focal adhesion kinase correlates with increased lymph node metastasis and poor prognosis in non-small-cell lung cancer

The aim of this study was to investigate whether focal adhesion kinase (FAK) overexpression correlates with lymph node metastases and prognosis. The protein expression of FAK was investigated in 153 paraffin-embedded tissues by immunohistochemical analysis and then correlated with various clinicopathologic parameters. FAK mRNA level was detected with quantitative RT-PCR in 57 NSCLC frozen tissues and 20 normal matched tissues. Immunohistochemistry showed FAK overexpression was significantly associated with positive lymph node metastasis and more advanced disease stage of NSCLCs and adenocarcinoma subtype; real-time PCR also indicated a statistically significant correlation between increased FAK mRNA level and the presence of nodal metastases. Moreover, in survival analysis, FAK overexpression was significantly associated with worse overall survival. FAK overexpression is a promising pathological factor to predict aggressive behavior and prognosis in patients with NSCLC, particularly in the adenocarcinoma subtype.