Prognostic factors including the expression of thyroid transcription factor 1 (TTF1) in patients irradiated for limited-disease small cell lung cancer

Aim: To investigate the impact of tumor-cell expression of thyroid transcription factor 1 (TTF1) on outcomes after irradiation of limited-disease small cell lung cancer (LD-SCLC). Patients and Methods: TTF1 expression plus eight factors were evaluated in 32 patients for locoregional recurrence-free survival (LRFS), metastasesfree survival (MFS) and overall survival (OS). These factors included age, gender, Karnofsky performance score (KPS), T-and N-category, respiratory insufficiency, smoking during radiotherapy and hemoglobin levels. Results: On univariate analysis of LRFS, no factor achieved significance. Improved MFS was associated with KPS >70 (p=0.029), N0-2 (p=0.003), no respiratory insufficiency (p=0.029) and nonsmoking states (p<0.001) on univariate analysis, and Ncategory (p=0.015) and non-smoking (p<0.001) on multivariate analysis. On univariate analysis, OS was associated with KPS >70 (p<0.001), N0-2 (p=0.002), no respiratory insufficiency (p=0.008) and non-smoking (p=0.022). On multivariate analysis, KPS (p=0.008) and Ncategory (p=0.018) remained significant. Conclusion: In contrast to other factors, TTF1-expression had no significant impact on outcomes after irradiation of LD-SCLC.