Clinical Significance of Thyroid Transcription Factor-1 in Advanced Lung Adenocarcinoma Under Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Treatment

TTF-1 shows independent prognostic significance in advanced lung adenocarcinoma. Patients with TTF-1-negative lung adenocarcinoma have not only shorter OS, but also shorter PFS under EGFR TKI treatment, despite the existence of mutant EGFR. Further studies are needed to investigate the optimal treatment of patients with TTF-1-negative lung adenocarcinoma.