ObjectiveTo explore the correlation between expression of thyroid transcription factor-1 (TTF-1) and gene mutation of epidermal growth factor receptor (EGFR) in patients with resectable lung adenocarcinoma (LAC). Method Sixty-seven LAC patients who underwent surgical resection in the Department of Cardiothoracic Surgery of Shanghai No.6 Hospital and Department of Thoracic Surgery, Renji Hospital, School of Medicine of Shanghai Jiaotong University from June 2009 to December 2012 were enrolled in this study. There were 40 male and 27 female patients with their age of 37-79 (56.7±1.8) years. TTF-1 expression was detected by immunohistochemistry. EGFR gene mutation was examined with mutant-enriched polymerase chain reaction. The correlation between TTF-1 expression and EGFR gene mutation was analyzed with corrected chi-square test. ResultsAmong the 67 LAC samples, 57 samples were TTF-1 positive and 10 samples were TTF-1 negative. There was EGFR gene mutation in 44 samples. EGFR gene mutation rate was 73.7% (42/57) in TTF-1 positive patients and 20.0% (2/10) in TTF-1 negative patients. The sensitivity of TTF-1 expression to predict EGFR mutation was 95.5%, and the specificity was 34.8%. ConclusionEGFR gene mutation rate is higher in LAC patients with positive TTF-1 expression. Positive TTF-1 expression can be used to predict EGFR gene mutation in LAC patients.