631 clinical application value of the systemic-immune-inflammation-index for predicting survival in patients with esophageal squamous cell carcinoma undergoing chemoradiotherapy or radiotherapy

Abstract The systemic immune-inflammation index(SII), a prognostic index integrating neutrophils, platelets and lymphocytes, has been shown to have predictive value for several common cancers. The study aim was to explore the clinical application value of the SII for prognosis of patients with esophageal squamous-cell carcinoma (ESCC) treated with radical chemoradiotherapy (CRT) or radiotherapy (RT). Methods Overall, 180 patients with ESCC who received radiotherapy with or without chemotherapy, from March 20, 2012 to December 25, 2017 were retrospectively analyzed. Based on serum measurements before/after/during treatment, the SII at ESCC was calculated by multiplying the sera absolute neutrophil and platelet counts, and then, divided by the absolute lymphocyte count. The Kaplan–Meier method and Cox proportional regression models were used to analyze the relationship between SII at different time points, the ratio of before and after radiotherapy and overall survival (OS). Results The area under ROC-curve of Ratio of SII before and after radiotherapy(RT-pre/Post-SII) was 0.635. The AUC of SII-values before, during and after radiotherapy was 0.618, 0.624 and 0.453, respectively. The cutoff-value of RT-pre/Post-SII was 0.498, and the patients were divided into low RT-pre/Post-SII group(<0.498) and high RT-pre/Post-SII group(≥0.498). RT-pre/Post-SII was related to tumor-length, KPS and severe thrombocytopenia in ESCC patients(P < 0.05). The median-OS in the high and low RT-pre/Post-SII group were 909 days, and 466 days, respectively. Multivariate analysis showed that KPS(P = 0.045), lymphatic-metastasis(P = 0.032), Mid-RT SII(P < 0.001) and RT-pre/Post-SII(P = 0.003) was independent prognostic factors affecting the prognosis of patients in ESCC treated with RT/CRT. Conclusion The calculation of SII value is simple, reliable and repeatable and can improve the accuracy of a patient’s prognosis. ESCC patients treated with RT or CRT with high SII before, and during radiotherapy are most likely to benefit from early anti-inflammatory or immunotherapy before and during radiotherapy, while immunological intervention for SII after radiotherapy is of little significance. Confirmation of these results by a large-sample prospective study is desirable.