Pretreatment systemic immune-inflammatory index (SII) for a prognostic impact in patients with locally advanced cervical cancer treated with concurrent chemoradiotherapy

OBJECTIVE: This study evaluates the predictive value of the systemic immune-inflammatory index (SII) in locally advanced cervical cancer treated with chemoradiotherapy and aims to develop a nomogram based on inflammatory and clinical-pathological factors to predict survival. MATERIALS AND METHODS: We retrospectively analyzed 421 stage IIB-IVA cervical cancer patients treated with chemoradiotherapy between 2012 and 2021. We analyzed the association between SII, other factors with overall survival (OS) and progression-free survival (PFS). And combined the variables to create a nomogram. RESULTS: Using SII cutoff value of 957, a high SII (>957) was associated with larger tumor size (P < 0.001), BMI (P = 0.005), FIGO stage (P = 0.008), ECOG performance status (P = 0.001) and lymph node metastasis (P = 0.003). Univariate Cox regression analysis indicated that higher SII was associated with worse PFS and OS. In the training cohort, multivariate analysis identified factors affecting OS, including SII ≥ 957 (hazard ratio [HR]: 1.65, 95% confidence interval [CI]: 1.02-2.66), larger tumor size (HR: 1.71, 95% CI: 1.08-2.7), poor ECOG (HR: 2.31, 95% CI: 1.29-4.12), and metastatic lymph nodes (HR: 1.91, 95% CI: 1.1-3.33). A high SII was also linked to poorer survival outcomes in the validation cohort and correlated with shorter PFS in both cohorts. The nomogram, including SII, accurately predicted 3- and 5-year survival rates with good discriminatory ability (concordance probability, 0.7), which was consistent across validation cohorts. CONCLUSION: Elevated SII was linked to poorer OS and PFS, which can help clinicians better assess and predict survival for these patients.