Tailored Second Line Treatment by Epidermal Growth Factor Receptor (EGFR) Mutation in Patients With Advanced Lung Adenocarcinoma

On the other hand, EGFR TKI (gefitinib or erlotinib) both produced somewhat similar higher response rate (around 25%) in general Taiwan adenocarcinoma NSCLC patients, while the median overall survival time didn't longer than chemotherapy treated patients. A recent prospective study of gefitinib in chemonaive adenocarcinoma NSCLC patients showed that the objective response rate was lower to be only 1.1% among EGFR mutation negative patients. Since typical EGFR gene mutations (i.e., the deletion of typically five amino acids at codons 746-750 (ELREA) in exon 19 and a leucine-to-arginine mutation at codon 858 (L858R)) are a good predictor for tumor response to tyrosine kinase inhibitor, this present study is to tailor the patient's treatment according to his/her EGFR gene mutation status. Receptor tyrosine kinase inhibitor (erlotinib in this study) will be the suggested second-line drug of recommendation for typical EGFR gene mutation patients, and chemotherapy (pemetrexed in this study) will be the suggested second-line drug of recommendation for EGFR wild type patients. The aim of this study is to increase the overall tumor response rate to 40% from current treatment outcome (around 25%) by this tailored second line treatment. The further interests of this study include prospectively evaluate the predictivity of EGFR gene mutation to tumor response. The primary objective of this study is to determine the overall tumor response rate of tailored second line treatment determined by typical EGFR gene mutation in patients with advanced lung adenocarcinoma.