Prognostic value and clinicopathological significance of pre-and post-treatment systemic immune-inflammation index in colorectal cancer patients: a meta-analysis

World J Surg Oncol. 2025 Jan 13;23(1):11. doi: 10.1186/s12957-025-03662-z.

Abstract

Background: In recent years, the association between systemic immune-inflammation index (SII) and the prognosis of patients with colorectal cancer (CRC) has remained a topic of considerable debate. To address this, the present study was carried out to investigate the prognostic significance of SII in CRC.

Methods: Databases including PubMed, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science were scrutinized up to March 27, 2024. The relationship between pre- and post-treatment SII levels and the prognosis of CRC was evaluated. Following literature screening, quality assessment, and extraction of outcome measures, a meta-analysis was conducted using Stata. Publication bias was assessed by funnel plots and Egger's test.

Results: A total of 27 studies were included in the analysis. Pooled results demonstrated that a high SII level was associated with poor overall survival (OS, HR = 1.78, 95% CI = 1.40-2.26), progression-free survival (PFS, HR = 1.80, 95% CI = 1.26-2.56), disease-free survival (DFS, HR = 1.91, 95% CI = 1.43-2.56), and recurrence-free survival (RFS, HR = 3.29, 95% CI = 1.58-6.88). Notably, the association between pre-treatment SII and OS, PFS, and DFS was stronger than that observed for post-treatment SII, indicating that treatment may attenuate the predictive valueof SII for survival outcomes. Additionally, elevated SII was correlated with poor tumor differentiation, tumor location in the rectum, and larger tumor size ≥ 5 cm.

Conclusion: Our meta-analysis suggested that a high SII is a predictor of poor prognosis in CRC patients. High SII levels were strongly correlated with inferior OS, PFS, DFS, and RFS. The relationship between SII and survival outcomes was attenuated post-treatment compared to pre-treatment. Additionally, elevated SII was correlated with clinicopathological factors in CRC patients. These findings suggest that SII can serve as an independent prognostic indicator for CRC.

Keywords: Colorectal cancer; Meta-analysis; Prognosis; Risk factors; Systemic immune-inflammation index.

Publication types

  • Meta-Analysis
  • Review

MeSH terms

  • Colorectal Neoplasms* / immunology
  • Colorectal Neoplasms* / mortality
  • Colorectal Neoplasms* / pathology
  • Colorectal Neoplasms* / therapy
  • Humans
  • Inflammation* / immunology
  • Inflammation* / pathology
  • Prognosis
  • Survival Rate