Prognostic and predictive value ofTTF-1 expression in patients with recurrent or advanced lung adenocarcinoma without sensitizing EGFR mutations or ALK translocation treated with platinum-based chemotherapy

Abstract

Abstract Background Pemetrexed (PEM) is an effective treatment for adenocarcinoma of the lung. Thyroid transcription factor-1 (TTF-1) has been proposed as a predictive biomarker of cancer sensitivity to PEM. Methods We retrospectively screened 197 cases of recurrent or advanced lung adenocarcinoma without sensitizing epidermal growth factor receptor (EGFR) mutations or anaplastic lymphoma kinase (ALK) translocation who underwent first-line platinum-based chemotherapy with or without PEM, and investigated the relationship between TTF-1 expression and treatment outcomes using propensity score matching. Results Univariate and multivariate analyses revealed that TTF-1 expression was an independent prognostic marker of progression-free survival (PFS) in all patients. After propensity score matching, 136 patients (102 TTF-1-positive patients and 34 TTF-1-negative patients) were selected. Among the 102 TTF-1-positive patients, the median PFS was 239 vs. 124 days in patients treated with PEM vs. non-PEM combination therapy (hazard ratio: 0.53; 95% CI: 0.35–0.79; p = 0.002). The median overall survival (OS) was 496 vs. 404 days in the patients treated with PEM vs. non-PEM combination therapy (hazard ratio: 0.74; 95% CI: 0.47–1.15; p = 0.1763). On the other hand, in the TTF-1-negative patients, the median PFS and OS were not significantly different between the PEM and non-PEM combination therapy groups. Conclusions Our results suggest that TTF-1 expression is a prognostic factor in patients with recurrent or advanced lung adenocarcinoma without EGFR or ALK alterations. In addition, PEM combination therapy prolonged PFS in these TTF-1-positive patients.