Thyroid Transcription Factor 1 (Ttf-1) And Overall Survival In Wild Type Egfr Patients Treated With Erlotinib.

e19113 Background: TTF-1 is a transcription factor involved in regulating epithelial to mesenchymal transition. TTF-1 has a favorable prognosis in early stage lung adenocarcinoma, although it’s prognostic value in erlotinib treated patients remains unknown (Somaiah ASCO 2011). The goal of this study was to validate the relationship between TTF-1 expression and clinical outcomes in wild-type (WT) stage IV non-small cell lung cancer (NSCLC) patients (pts) treated with erlotinib. Methods: Pts that received erlotinib were retrospectively analyzed by IHC for TTF-1 expression (positive = greater than 5% of tumor cells with moderate (2+) or strong (3+) nuclear staining). Pts’ tumors were considered WT if no mutations were detected in Exon 19 or L858R (Exon 21) using single-strand conformation polymorphism and sequence-specific polymerase chain reaction (PCR). Log Rank was used to correlate TTF-1 positivity with outcomes. Results: 216 pts were analyzed. EGFR activating gene mutations were found in 11.6% of cases....