Role of cMET expression in non-small cell lung cancer patients treated with EGFR tyrosine kinase inhibitors.

Abstract

e18092 Background: We performed this study to investigate whether activation of cMET is associated with sensitivity to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) in non-small-cell lung cancer (NSCLC) patients. Methods: This retrospective study included 69 NSCLC patients with available tumor tissue, treatment response and survival data. cMET and hepatocyte growth factor (HGF) status was evaluated by immunohistochemistry. Results: A positive cMET, cMET[pY1003], cMET[pY1234/1235] and HGF were identified in 89%, 44%, 20% and 89% of cases, respectively. Positive cMET[pY1003] expression was associated with better objective response rate (OR) and clinical benefit rate (CBR) (OR, P = 0.033 and CBR, P = 0.039). Positive cMET[pY1234/1235] was significantly associated with a longer overall survival (OS) (P = 0.012) and time-to progression (TTP) (P = 0.031). Multivariable model confirmed that cMET[pY1234/235]-positive patients had a significant reduction in the risk of death and disease progression than cMET[pY1234/1235] –negative patients [OS; hazard ratio(HR)=0.29, P = 0.008 and TTP; HR=0.43; P=0.024] Conclusions: cMET expression in tumor tissue could be useful for predicting the clinical outcome of EGFR-TKIs treatment. Our results suggest that cMET expression in tumor tissue could be used to refine the selection of NSCLC patients expected to benefit from EGFR-TKIs treatment.