Abstract
BACKGROUND AND OBJECTIVE: It has been proven that Kelch-like ECH-associated protein 1 (Keap1) expression was correlated with the chemoresistance of platinum drugs. The aim of this study is to investigate the protein expression levels of Keap1 in non-small cell lung cancer (NSCLC) patients as well as to correlate its expression with the response rate (RR), progression-free survival (PFS), and overall survival (OS) of patients treated with platinum-based first-line chemotherapy. METHODS: The immunohistochemical analysis of Keap1 expression was performed using tumor samples from 50 patients with stage III or IV NSCLC. RESULTS: The high expression ratio of Keap1 was 26.0%. The Keap1 expression was significantly correlated with the RR and PFS after platinum-based chemotherapy (P<0.05) but not with the gender, age, smoking, pathology type, differentiation, metastasis, and OS (P>0.05). The PFS was significantly longer in patients with high Keap1 expression than in those with low/negative expression (P=0.002). Furthermore, the level of Keap1 expression was an independent predictive factor of PFS after platinum-based first-line chemotherapy (P=0.007). CONCLUSIONS: The expression of Keap1 was significantly correlated with the RR and PFS of platinum-based first-line chemotherapy. Therefore, Keap1 may be a useful biomarker for predicting the chemosensitivity of patients with advanced-stage NSCLC.