Patel N, et al. – The efficacy and toxicity of gefitinib were compared as first–line therapy and second–line therapy for advanced lung adenocarcinoma patients with positive exon 21 (L858R) or exon 19 deletion of epidermal growth factor receptor (EGFR) mutation. In investigations, advanced lung adenocarcinoma patients treated with gefitinib therapy had significantly longer median progression–free survival (mPFS) in the first–line therapy than that in the second–line therapy. Findings suggested that EGFR mutation types probably influence the response to gefitinib therapy.