Abstract
Objective: In recent years, studies have demonstrated the prognostic importance of the systemic immune inflammation index (SII) and the systemic inflammation response index (SIRI) in gastric cancer. We aimed to determine the prognostic significance of SII and SIRI in patients with locally advanced gastric cancer who underwent perioperative fluorouracil, leucovorin, oxaliplatin, and docetaxel therapy at our center.
Material and Methods: Our study was a retrospective, single-center study that included 167 patients with locally advanced gastric cancer between June 2019 and December 2023.
Results: The SII parameter demonstrated very high discriminatory power [area under the curve (AUC)=0.963; 95% confidence interval (CI): 0.938-0.988]. For a cut-off value of ≥664.00, the sensitivity was 87.1% and, the specificity was 87.8%, and the result was statistically significant (p<0.001). Similarly, the SIRI value exhibited high predictive performance (AUC=0.952; 95% CI: 0.922-0.982). For a cut-off value of ≥1.27, the sensitivity was 88.2%, and the specificity was 89.2%, establishing this parameter as a strong predictor of mortality (p<0.001). In patients with SII <664.00, the 2-year and 5-year overall survival (OS) rates were 94.7% and 83.7%, respectively, while in the SII ≥664.00 group, the 2-year OS dropped to 13.9%, and the 5-year OS could not be calculated (p<0.001). A similar trend was observed in terms of SIRI; In patients with SIRI <1.27, the 2-year OS was 88.1% and the 5-year OS was 85.3%, while in the SIRI ≥1.27 group, the 2-year OS decreased to 19.4% (p<0.001). According to the multivariate Cox regression analysis results, having an SII ≥664.00 increased the risk of death 8.49 times [Hazard ratio (HR): 8.49; 95% CI: 4.35-16.57; p<0.001], and having a SIRI ≥1.27 increased the risk of death 7.88 times (HR: 7.88; 95% CI: 3.99-15.60; p<0.001). Similarly, having an SII ≥664.00 increased the risk of progression 5.13 times (HR: 5.13; 95% CI: 3.14-8.39; p<0.001) and having a SIRI ≥1.27 increased the risk of progression 3.89 times (HR: 3.89; 95% CI: 2.39-6.31; p<0.001).
Conclusion: There is a need for biomarkers that can be used clinically for prognostic and predictive purposes in gastric cancer patients. Lower SII and SIRI levels are significantly associated with improved OS and disease-free survival in patients with gastric cancer. More comprehensive analyses that combine it with other markers have been and continue to be conducted.