EGFR and lung adenocarcinoma: For lung adenocarcinoma with the EGFR 19Del mutation, the Observation group showed a better ORR (81.8% vs 54.3%), and mPFS (14.5 vs 11.0 months) than the Control group, and the differences were statistically significant (P < .05), but DCR (95.5% vs 91.4%), 1-year survival (90.9% vs 85.7%), and 2-year survival (72.7% vs 60.0%) were not significantly different (P > .05).