Thyroid transcription factor-1 level is associated with epidermal growth factor receptor mutation status in patients with advanced lung adenocarcinoma

Abstract

Epidermal growth factor receptor (EGFR) mutation status plays an important role in individual treatment of non-small cell lung cancer.However clinical tissue samples for mutation detection are not always available in advanced NSCLC. Thus an alternative method of EGFR mutation detection is required in NSCLC treatment.Recent studies have associated thyroid transcription factor 1 (TTF-1) with EGFR mutations in lung cancer.In this study, we detected expression of TTF-1 and EGFR mutations in 102 patients with advanced NSCLC and investigated the possibility of TTF-1 as a potential indicator of EGFR status. Serum and tissue samples were collected from 102 patients with advanced NSCLC including 28 cases of EGFR mutation in 19 exon, 23 cases of EGFR mutation in 21 exon and 51 cases of WT EGFR. Protein levels of TTF-1 in serum were quantified by enzyme-linked immunosorbent assay (ELISA).Levels of TTF-1 in tissues were detected by immunohistochemistry (IHC). SPSS 17 statistical software was used to analyze the data. In the serum the expression of TTF-1 in EGFR 19 and 21 exon MT groups both was higher than that in the WT group(19MT vs 21MT vs WT: 0.092 vs 0.083 vs 0.045; F = 27.653, P < 0.01), and the result of the tissues was the same (19MT vs 21MT vs WT: 0.682 vs 0.644 vs 0.441; F = 47.665, P < 0.01), but no differences between two MT groups were observed (P > 0.05). The ELISA results and the IHC results were consistent (r = 0.87, P < 0.01). The expression of TTF-1 in serum showed a relationship with smoking history (χ² = 4.639, P < 0.05), but not with sex, age, TNM stage and metastasis (P > 0.05). These results indicated that TTF-1 expression was upregulated in EGFR mutated NSCLC compared to EGFR WT NSCLC. The level of TTF-1 maybe used as a potential marker of EGFR mutation status.