Prognostic significance of systemic immune-inflammation index in hepatocellular carcinoma: a meta-analysis.

Purpose: Emerging evidence suggests an association between the systemic immune-inflammation index (SII) and the survival outcomes of individuals with hepatocellular carcinoma (HCC). However, existing research findings are inconsistent, and no definitive conclusions have been reached. This research aimed to explore the predictive accuracy of the SII in patients with HCC.

Methods: Numerous databases, encompassing PubMed, Embase, Web of Science, and Cochrane Library, were thoroughly retrieved from the database inception until January 14, 2025, to identify studies on the correlation between SII and survival outcomes in HCC. Studies were screened according to pre-established eligibility criteria. The primary endpoints included overall survival (OS), recurrence-free survival (RFS), and progression-free survival (PFS), which were appraised via hazard ratios (HRs) with corresponding 95% confidence intervals (CIs).

Results: 39 high-quality cohort studies involving 47 comparison groups were included in this analysis. As proven by the aggregated data, increased SII was significantly linked to shorter OS (HR = 1.64, 95% CI: 1.45-1.85; p < 0.00001), RFS (HR = 1.68, 95% CI: 1.44-1.96; p < 0.00001), and PFS (HR = 1.48, 95% CI: 1.20-1.82; p = 0.0002) in individuals with HCC. Furthermore, subgroup analyses revealed that age, region, intervention strategy, and SII thresholds affected the validity of SII for predicting the prognosis of HCC.

Conclusion: In HCC patients treated with monotherapy or combination therapy, a higher SII before treatment is significantly associated with shorter OS, RFS, and PFS. SII may serve as an important biological indicator for assessing the prognosis of HCC, providing a critical reference for the scientific and systematic treatment of HCC.