Home›Oncology› Elevated pretreatment SII linked to worse survival in gastric cancer across 31,608 patients
Elevated pretreatment SII linked to worse survival in gastric cancer across 31,608 patientsHigh Immune Inflammation Levels May Predict Poorer Outcomes for Gastric Cancer Patients
Frontiers in MedicinePublished October 31, 2026DOI ↗Editorial oversight: Dr. Julia Lee, PhD · Oncology, Genomics & Drug Development
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Key Takeaway
Consider elevated pretreatment SII as a potential prognostic marker in gastric cancer, pending prospective validation.
This systematic review and meta-analysis pooled data from 61 studies (66 cohorts, 31,608 patients) to examine the association between elevated pretreatment systemic immune-inflammation index (SII) and survival outcomes in gastric cancer. Nearly all included studies were retrospective, with only one prospective study.
Elevated pretreatment SII was significantly correlated with inferior overall survival (HR 1.48, 95% CI 1.36-1.62), progression-free survival (HR 1.43, 95% CI 1.30-1.58), and recurrence-free survival (HR 1.38, 95% CI 1.09-1.76). These associations were consistent across the pooled analyses.
The authors note that the evidence base is limited by the predominance of retrospective designs and state that prospective validation is required before routine clinical implementation. No data on adverse events or tolerability were reported, as expected for a prognostic biomarker review.
The findings suggest that pretreatment SII may serve as a potential biomarker for adverse prognosis in gastric cancer, but the observational nature of the included studies means no causal relationship is established. The pooled hazard ratios should not be interpreted as absolute survival differences.
How this fits prior evidence
This meta-analysis extends prior coverage of prognostic and treatment-related factors in gastric cancer, including findings that older adults achieve comparable survival despite higher toxicity and that neoadjuvant apatinib-based regimens yield high R0 resection rates. Unlike those reports, which focus on treatment outcomes or age-related differences, this review addresses a readily available pretreatment inflammatory index. It also aligns with the broader theme of identifying biomarkers in gastrointestinal cancers, as seen with fungal dysbiosis and AI tongue image analysis, but the predominantly retrospective evidence base limits immediate clinical application.
Researchers looked at a large group of over 31,000 people with gastric cancer. They studied a specific marker called the systemic immune-inflammation index, or SII. This marker looks at how the body's immune system and inflammation levels interact before treatment begins.
The study found that patients with a high SII score had a much lower chance of surviving for a long time. Specifically, these patients were more likely to see their cancer progress or return more quickly compared to those with lower scores. This suggests the marker could help doctors identify who might need more intensive care.
While these results are very consistent across many studies, most of the data came from looking back at old medical records. Because of this, doctors cannot use this test as a standard tool just yet. More forward-looking studies are needed to prove exactly how this marker can help in daily hospital care.
What this means for you:
High immune-inflammation scores are linked to shorter survival times in patients with gastric cancer.
Common questions
What is the systemic immune-inflammation index (SII)?
SII is a number calculated from routine blood test results, combining counts of certain immune and inflammatory cells. In this review, it was measured before treatment in people with gastric cancer. Researchers looked at whether higher SII values were linked to survival. It is not yet a standard test used to guide cancer treatment.
Does a high SII mean my cancer is worse?
Not necessarily for any one person. This review found that, across groups of patients, higher pretreatment SII was linked to poorer survival on average. That is a group-level link, not a prediction for an individual. Only your care team can interpret your blood results in the context of your full health picture.
How strong is the evidence behind this finding?
The evidence is limited. The review included 61 studies and 31,608 patients, but nearly all were retrospective, meaning they looked back at existing records. Only one study was prospective. The authors say prospective validation is needed before this marker could be used in routine clinical practice.
Could SII be used to guide my treatment now?
No. The authors describe SII as a potential biomarker for poorer prognosis, not a validated or actionable one. They state that prospective validation is required before routine clinical implementation. Treatment decisions should be based on your care team's assessment, not on this early research finding.
ObjectiveTo comprehensively assess the association of pretreatment systemic immune-inflammation index (SII) with the prognosis of gastric cancer patients.MethodsPubMed, Web of Science, Embase, and the Cochrane Library were searched to select studies exploring the association of SII with the overall survival (OS), progression-free survival (PFS) or recurrence-free survival (RFS) of gastric cancer. We pooled the hazard ratios (HRs) with 95% confidence intervals (CIs) using a random-effects model. Robustness was assessed by sensitivity analyses, and publication bias was evaluated using funnel plots and Egger’s regression test.ResultsA total of 61 studies involving 66 cohorts and 31,608 patients were included in this meta-analysis, with most studies adopting a retrospective design and only one prospective study enrolled. Elevated pretreatment SII was significantly correlated with inferior OS (HR = 1.48, 95% CI: 1.36–1.62), PFS (HR = 1.43, 95% CI: 1.30–1.58), and RFS (HR = 1.38, 95% CI: 1.09–1.76). Subgroup analyses demonstrated that the magnitude of the prognostic association varied across treatment modalities and geographic regions.ConclusionIn conclusion, we found that elevated pretreatment SII is a potential biomarker for adverse prognosis in gastric cancer patients. However, since nearly all included studies were retrospective and only one was a prospective study, our findings support the prognostic value of SII, but prospective validation is required before routine clinical implementation.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/, identifier CRD420261321880.
