EGFR and lung adenocarcinoma: In a previous study, we evaluated the efficacy of RT-PCR testing on liquid-based cytology specimens in lung adenocarcinoma patients and found that the disease control rate (DCR) and median PFS (89.0% and 13.8 months, respectively) in patients with EGFR gene mutation were higher than those in patients without EGFR gene mutation (30.8% and 1.4 months, respectively) [23].