Gefitinib Efficacy Associated with Multiple Expression of HER Family in Non-small Cell Lung Cancer

Abstract

The aim of this study was to compare the relationship between HER family expression and clinical response to gefitinib. Patients and Methods: Tissues from thirty-one non-small cell lung cancer (NSCLC) patients treated with a monotherapy of gefitinib were analyzed. Expressions of HER family in 31 tumors were examined by immunohistochemistry. Results: The total expressions were 21 for EGFR (68%), 24 for HER2 (77%), 17 for HER3 (55%) and 4 for HER4 (13%). Fourteen out of 31 (45%) demonstrated triple expression of EGFR and HER2, as well as HER3 or HER4. A significantly better response rate (RR) and time to progression (TTP) were observed for the group with the triple expression than for the other groups (RR 50 vs. 11%; p<0.05, median TTP 4.29 vs. 1.2 months; p<0.05). Conclusion: Mutliple expression of the HER family might be related with the clinical response to gefitinib and EGFR mutation status.