Purpose: It has been suggested that hepatocyte growth factor (HGF) and insulin-like growth factor binding protein (IGFBP)-3 are associated with gefitinib resistance in non-small cell lung cancer (NSCLC). We investigated the predictive and prognostic roles of these proteins in NSCLC patients treated with gefitinib.
Patients and methods: Of 106 patients enrolled in a randomized phase II study of gefitinib, 97 had plasma samples available for ELISA testing. Of these samples, seven and eight, respectively, had HGF and IGFBP-3 values that could not be measured. Therefore, the correlations between clinical outcomes and plasma levels of HGF and IGFBP-3 were evaluated in 90 and 89 patients, respectively.
Results: Plasma HGF levels were significantly higher in older patients, male patients, patients with squamous cell carcinoma, current smokers, and patients with epidermal growth factor receptor (EGFR) wild-type tumors. Low HGF levels were significantly associated with higher response rate, and longer progression-free survival (PFS) and overall survival (OS) irrespective of EGFR mutation status. In a multivariate analysis, the presence of EGFR mutations (P=0.002) and low HGF levels (P=0.031) were independently predictive of longer PFS, and an ECOG PS of 0 (P=0.001) and low HGF levels (P=0.002) were independently predictive of longer OS. No statistically significant differences were found for IGFBP-3.
Conclusion: High HGF levels are significantly associated with resistance to gefitinib and can be used as a predictive marker for the differential outcome of gefitinib treatment in NSCLC irrespective of EGFR mutation status.
Trial registration: ClinicalTrials.gov NCT00452244.
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