Baseline Tumor Size as a Predictive and Prognostic Factor of Immune Checkpoint Inhibitor Therapy for Non-small Cell Lung Cancer

BACKGROUND/AIM: Immune checkpoint inhibitors (ICI) are a novel medication for non-small cell lung cancer (NSCLC). Recent reports indicated that baseline tumor size (BTS) relates to the efficacy of ICI therapy for melanoma, but no study exists for NSCLC. This study aimed to evaluate the utility of BTS for ICI therapy. PATIENTS AND METHODS: Data from 58 patients diagnosed with NSCLC who underwent ICI monotherapy, were retrospectively analyzed. Patients were divided into two groups according to BTS (below 101 mm, above 101 mm). The primary endpoint was progression-free survival (PFS) and the secondary endpoint was overall survival (OS). RESULTS: PFS of patients with a large BTS was significantly shorter than that of those with a small BTS (median; 2.07 95% confidence interval [CI=0.99-6.77] months versus 6.39 95%CI=4.17-11.50 months) (p=0.044). OS of patients with large BTS was also significantly shorter (p<0.01). CONCLUSION: BTS is a predictive and prognostic negative factor of ICI therapy for NSCLC.