Abstract 991
Aim/Background
Immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) are reliable ways to identify overexpression of c-Met protein or amplification of the c-Met gene, but each technique requires a high-quality tissue sample, which may not be available. The aim of this study is to investigate whether plasma soluble c-Met level can be used to predict tissue c-Met status in patients with advanced non-small cell lung cancer (NSCLC).
Methods
In 198 patients with advanced NSCLC, we determined c-Met expression by IHC analysis on tumors. The expression was scored according to MetMAb scoring criteria. Plasma concentration of soluble c-Met protein was measured with a human soluble c-Met quantitative enzyme-linked immunosorbent assay (ELISA) kit, and the predictive values were determined based on the receiver-operating characteristic (ROC) curves analysis.
Results
Of the total 198 patients, 103 (52%) patients were tissue c-Met negative, 95(48%) were tissue c-Met positive. The average plasma c-Met concentration was 682.8 ± 155.2 ng/mL in the tissue c-Met-negative group, significantly lower than 886.5 ± 307.4 ng/mL in tissue c-Met- positive group (P < 0.001). ROC curve analysis showed 66.9% specificity and 64.2% sensitivity for predicting tissue c-Met positivity at 755ng/mL of plasma c-Met. AUC for plasma c-Met was 0.724 (95% confidence interval; 0.654–0.794, P < 0.001).
Conclusions
We suggest 755 ng/mL in the plasma as a cutoff for predicting tissue c-Met status with moderate specificity and sensitivity. This information may be useful when the tumour tissue is not available.
Clinical trial identification
Disclosure
All authors have declared no conflicts of interest.