Prognostic and clinicopathological role of pretreatment systemic inflammation response index (SIRI) in gastric cancer: a systematic review and meta-analysis

BACKGROUND: The systemic inflammatory response index (SIRI) is calculated via the following formula: SIRI = monocyte count × neutrophil count/lymphocyte count. The value of the SIRI in predicting the prognosis of gastric cancer (GC) remains controversial. This study revealed the precise effect of the SIRI in predicting GC prognosis through a meta-analysis. METHODS: The ability of the SIRI to predict GC prognosis was evaluated by calculating combined hazard ratios (HRs) and 95% confidence intervals (CIs). Furthermore, the combined odds ratios (ORs) and 95% CIs were determined to analyze the associations between the SIRI and the clinicopathological characteristics of patients with GC. RESULTS: Seven publications on a total of 1763 cases were included in this study. The SIRI threshold was between 0.58 and 1.35, and the median value was 0.85. Our pooled findings revealed that a higher SIRI was significantly linked with poor overall survival (OS) (HR = 1.87, 95% CI = 1.59-2.20, p < 0.001) and disease-free survival (DFS; HR = 1.88, 95% CI = 1.50-2.36, p < 0.001) in GC patients. However, the SIRI did not exhibit a significant association with sex (OR = 1.98, 95% CI = 0.82-4.75, p = 0.126), surgery type (OR = 0.96, 95% CI = 0.61-1.51, p = 0.847), tumor differentiation (OR = 0.75, 95% CI = 0.54-1.06, p = 0.099), or TNM stage (OR = 1.25, 95% CI = 0.34-4.62, p = 0.743) in patients with GC. CONCLUSIONS: An elevated SIRI was significantly associated with unfavorable OS and DFS in patients with GC. Thus, the SIRI is a reliable biomarker for predicting GC prognosis in clinical practice.