EGFR and lung adenocarcinoma: Our study demonstrates that the 1st-line chemotherapy followed by EGFR-TKIs in patients with EGFR mutation advanced lung adenocarcinoma had a better OS than that of the 1st-line TKIs followed by 2nd-line chemotherapy in these patients (median: 662 versus 390 days, p < 0.0001; Figure 1(b) and Table 2).