Survival outcomes in TTF-1 negative non-squamous non-small cell lung cancer (H-LINK 001).

BACKGROUND: The impact of TTF-1 expression on outcomes in patients with non-squamous non-small cell lung cancer (NSCLC) has increasingly been reported. However, information on the characteristics and outcomes of patients with non-squamous NSCLC in whom TTF-1-negativity was confirmed using different antibody clones remains scarce. METHODS: We conducted a multicenter retrospective study and analyzed the data of patients with non-squamous NSCLC in which TTF-1-negativity was confirmed in each participating institution. Patients were eligible if they had an EGFR/ALK-wild type tumor and received first-line treatment with an immune checkpoint-containing regimen. Clinical information, including the TTF-1-antibody used in each institution, was collected. RESULTS: Data of 70 patients with non-squamous NSCLC and negative TTF-1 expression were analyzed. The patients were subdivided into SPT24- and 8G7G3/1-confirmed groups according to the TTF-1-antibody clone used to confirm TTF-1-negativity. Multivariate analysis using the Cox proportional hazard model revealed that the SPT24-confirmed group had a significantly increased risk of death (hazard ratio: 3.20, 95% confidence interval: 1.23 − 8.29), but not a significant association with the risk of disease progression. Meanwhile, the neutrophil/lymphocyte ratio was significantly associated with both the risk of disease progression and death. CONCLUSION: TTF-1-negative non-squamous NSCLC patients who were diagnosed using the SPT24 antibody clone exhibited significantly shorter overall survival than those who were diagnosed using the 8G7G3/1 antibody clone, and NLR may be a useful predictor for the prognosis of patients with TTF-1-negative non-squamous cell NSCLC.