Prognostic value of systemic immune-inflammation index in patients with pancreatic cancer: a meta-analysis

The systemic immune-inflammation index (SII) is a significant prognostic factor in some cancer types. However, the prognostic value of SII in patients with pancreatic cancer (PC) remains controversial. This study aimed to evaluate the prognostic impact of SII in patients with PC through a meta-analysis. This meta-analysis is aimed to investigate the prognostic significance of SII in patients with PC. Relevant articles were obtained through a systematic search. Hazard ratios (HRs) and 95% confidence intervals (CIs) were used to estimate the association between SII and survival outcomes, including overall survival (OS), cancer-specific survival (CSS), disease-free survival (DFS), and progression-free survival (PFS). Seven studies with 2132 patients were included in the meta-analysis. The results revealed that elevated pretreatment SII was associated with poor OS (HR = 1.55, 95% CI: 1.34–1.78, p < 0.001) and inferior CSS/DFS/PFS (HR = 1.51, 95% CI: 1.27–1.80, p < 0.001). The prognostic role was reliable in a subgroup analysis conducted according to regions, disease status, survival analysis, and cutoff value. High SII was associated with poor OS in patients with PC. Therefore, SII is suggested to be a cost-effective biological marker for monitoring survival in patients with PC.