In the subset of patients with EGFR mutant lung adenocarcinoma, no significant survival difference was found between patients with tumors carrying exon 19 deletions and patients harboring exon 21 p.L858R point mutation (mOS 47.0 vs. 58.7 mo, HR 1.02, 95% CI 0.34–3.08, p = 0.977). This evidence concerns the gene EGFR and lung adenocarcinoma.