Abstract
BACKGROUND: The prognostic significance of the systemic inflammatory response index (SIRI) in patients with cancer receiving programmed cell death 1 (PD-1)/PD-1 ligand 1 (PD-L1) immune checkpoint inhibitors (ICIs) has been widely investigated; however, the results have been conflicting. As such, the present meta-analysis aimed to analyze the precise significance of the SIRI in predicting prognosis in patients with cancer undergoing ICI therapy. METHODS: A comprehensive literature search of the Web of Science, PubMed, Embase, and Cochrane Library databases for relevant studies, published from inception to April 25, 2024, was performed. The SIRI was analyzed for its prognostic utility in patients undergoing ICI therapy by calculating combined hazard ratios (HRs) and corresponding 95% confidence intervals (CIs). RESULTS: Six studies comprising 1133 patients were included in the analysis. Pooled data revealed that a higher SIRI was significantly associated with poor overall survival (OS) (HR 1.96 [95% CI 1.55-2.47]; p < 0.001) and progression-free survival (PFS) (HR 1.41 [95% CI 1.19-1.67]; p < 0.001) for patients who underwent PD-1/PD-L1 ICI treatment. Subgroup analysis revealed that SIRI was markedly associated with dismal OS and PFS, independent of sample size, cut-off value, and survival analysis (p < 0.05). The findings were verified to be robust against publication bias and sensitivity analyses. CONCLUSION: In summary, an elevated SIRI was significantly associated with OS and PFS in patients with cancer undergoing PD-1/PD-L1 ICI treatment. SIRI may a candidate indicator for predicting the prognosis of patients undergoing ICI therapy.