RELATIONSHIP BETWEEN EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) MUTATION, THYROID TRANSCRIPTION FACTOR 1 (TTF-1), AND PROGNOSIS OF PATIENTS WITH NON-SMALL-CELL LUNG CANCER

Objective: This study aimed to explore the relationship between thyroid transcription factor 1 (TTF-1) expression, epidermal growth factor receptor (EGFR) mutations, and prognosis of patients with non-small-cell lung cancer (NSCLC). Materials and methods: A total of 240 tissue samples were collected, and TTF-1 expression was assessed via immunohistochemistry, while EGFR mutations were assessed via direct sequencing. The survival curve was mapped using Kaplan-Meier analysis, and P<0.05 was considered to be statistically significant. Results: The overall rate of positive TTF-1 expression (TTF-1(+)) was 92.75%. Specifically, the rate of TTF-1(+) expression was approximately 88.41% and 47.37% in female and male patients, respectively. Non-smokers with early stage (I) NSCLC had a high positive expression rate. Meanwhile, the rate of TTF-1(+) expression was 92.68% and 83.78% in patients with EGFR mutation-positive lung cancer and in those with mutation-negative malignancy who had a performance status score of 0, respectively. Further analysis of the survival curves showed that EGFR patients with mutation-positive malignancy had longer survival than those with mutation-negative malignancy. Furthermore, patients with EGFR mutations in exon 21 had a statistically significantly better survival (P<0.001) compared to those with exon 21 mutation-negative lung cancer. Conclusions: Positive TTF-1 expression is correlated with EGFR mutations in patients with lung cancer, and the prognosis of patients with TTF1-positive tumors is better than those with TTF1-negative tumors.