Preoperative serum LMTK3 as a novel biomarker in non-small cell lung cancer.

The lemur tyrosine kinase-3 (LMTK3) has been reported to be involved in tumor progression. The aim of this study was to determine the diagnostic and prognostic significances of preoperative serum LMTK3 in non-small cell lung cancer (NSCLC) patients. Sera were collected from 100 healthy volunteers (HV), 280 benign lung diseases (BLD) patients, and 524 NSCLC patients prior to operation. The serum LMTK3 level was detected by ELISA. We found that serum LMTK3 level was markedly elevated in NSCLC patients compared with controls. The receiver operating characteristic (ROC) curve suggests that serum LMTK3 is a good diagnostic and differential marker for discriminating NSCLC patients from BLD. NSCLC patients with LMTK3 level ≥6.85 ng/ml had significantly worse survival than patients with LMTK3 <6.85 ng/ml. In multivariate analysis, LMTK3 level ≥6.85 ng/ml was an independent factor of poor prognosis [hazard ratio (HR) = 2.95; p = 0.011] after adjusting for age, sex, smoking behavior, stage, and histology. The Kaplan-Meier survival curves showed the consistent trend. Preoperative serum LMTK3 is a novel diagnostic and independent prognostic biomarker in patients with NSCLC.