The Predictive Effect of the Systemic Immune-Inflammation Index for Patients with Small-Cell Lung Cancer

Aim: The purpose of this study was to investigate the predictive power of the systemic immune inflammation index (SII) based on neutrophil (N), platelet (P) and lymphocyte (L) on the clinical outcomes of patients with SCLC. Patients & methods: Blood samples of 228 patients were obtained 1 week before treatment to measure the SII (SII = P × N/L). Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan–Meier curves and Cox regression models. Results: Higher SII was associated with poorer OS (p < 0.001) and poorer PFS (p < 0.001). Multivariable analyses further revealed SII as an independent prognostic factor for OS (p < 0.001) and PFS (p < 0.001). Conclusion: Pretreatment SII was a valuable prognostic factor for PFS and OS in SCLC patients.