Systemic Immune-Inflammation Index as a Prognostic Marker of Late Recurrence in Operable Gastric Cancer: a Dual-Center Study

Abstract

Aim To evaluate the prognostic role of the systemic immune-inflammation index (SII) in patients with operable gastric cancer. Methods We assessed 354 patients with operable gastric cancer from tertiary centers in Turkey. SII was calculated by following formula: [neutrophil (cells x 10(9)/L) x platelet (cells x 10(9)/L)]/lymphocyte (cells x 10(9)/L). The best cut-off value for SII was determined by using "receiver operating characteristics (ROC)" analysis. We used log-rank and Cox-regression analysis for survival analyses. Results One hundred twenty patients were in the late recurrence group (recurrences have developed 36 months after the surgery). SII was not a prognostic factor in the early recurrence group. However, relapse-free survival (RFS) was longer in SII-low patients than SII-high patients in the late recurrence group. In multivariable analysis, SII was the only independent prognostic factor for RFS in the late recurrence group (hazard ratio (HR): 5.42, 95% CI: 1.18-24.82, p = 0.03). Conclusion SII was an independent prognostic factor for RFS in GC patients with late recurrence. Late recurrence risk was higher in SII-high patients than SII-low patients. Inflammation contributes to tumor progression, invasion, and metastasis. Prolonged exposure to chronic inflammation could explain the results of this study.