Clinical utility of the systemic immune-inflammation index for predicting survival in esophageal squamous cell carcinoma after radical radiotherapy.

Aim: To explore the clinical utility of the systemic immune-inflammation index (SII) for predicting the prognosis of esophageal squamous cell carcinoma (ESCC). Patients & methods: After calculating the SII in 180 patients with ESCC, the relationship between SII values and the pre-/post-radiotherapy SII ratio and overall survival was determined. Results: The median overall survival was 649 days for the entire group and 909 and 466 days for the high and low pre-/post-radiotherapy SII ratio groups, respectively. Multivariate analysis identified Karnofsky performance status (p = 0.045), lymphatic metastasis (p = 0.032), mid-radiotherapy SII (p < 0.001) and pre-/post-radiotherapy SII ratio (p = 0.003) as independent prognostic factors. Conclusion: The pre-/post-radiotherapy SII ratio and mid-radiotherapy SII are potentially effective markers for predicting ESCC prognosis.