Association of thyroid transcription factor-1 with the efficacy of immune-checkpoint inhibitors in patients with advanced lung adenocarcinoma.

Background: We aimed to identify the relationship between thyroid transcription factor-1 (TTF-1) expression of lung adenocarcinoma and the efficacy of immune-checkpoint inhibitor (ICI) therapy.

Methods: This retrospective multicenter study comprised patients with advanced lung adenocarcinoma treated with ICI monotherapy. We collected clinical medical records including data on TTF-1 expression and analyzed the relationship between TTF-1 expression and programmed death-ligand 1 tumor proportion score (PD-L1 TPS), objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).

Results: In total, 108 patients with lung adenocarcinoma were analyzed. The rate of TPS ≥1% and ≥50% in patients with positive TTF-1 expression was significantly higher than that in patients with negative TTF-1 expression (88% vs. 60%, p < 0.001; 65% vs. 24%, p < 0.001). The ORR was significantly higher in TTF-1 positive patients than in TTF-1-negative patients (38% vs. 8%, p = 0.003). Among patients with TPS ≥50% and 1%-49%, the ORR in TTF-1 positive and negative patients was 48% (26/54) versus 17% (1/6) (p = 0.21), and 32% (6/19) versus 11% (1/9) (p = 0.37), respectively. The ORR for patients with TPS <1% was 0% in both the TTF-1 negative and positive cases. The median PFS and OS was significantly longer in TTF-1-positive patients than in TTF-1-negative patients (5.4 vs. 1.6 months, p < 0.001; 18.2 vs. 8.0 months, p = 0.041). Multivariate analysis revealed that TTF-1-negative status was an independent unfavorable prognostic factor for PFS.

Conclusion: Patients with TTF-1-positive status receiving ICI monotherapy showed better outcomes than those with TTF-1-negative lung adenocarcinoma.