Predictive value of systemic immune-inflammation index combined with clinical staging for prognosis of esophageal cancer patients / 中华放射医学与防护杂志

ABSTRACT

Objective:To investigate the relationship between systemic immune-inflammation index (SII) and the prognosis of esophageal cancer patients treated with radical radiotherapy and to predict the prognosis of the patients using the SII combined with clinical staging.Methods:A retrospective analysis was conducted for 248 patients with esophageal cancer who were admitted to the Department of Radiotherapy in the Fourth Hospital of Hebei Medical University between 2014 and 2016. These patients included 146 males and 102 females, with a median age of 67 years. Among them, 134 patients received concurrent chemotherapy and 114 patients received radiotherapy alone. The SII before radiotherapy was defined as platelet count × neutrophil count/lymphocyte count. The patients were divided into a low-SII group and a high-SII group according to the optimal cutoff value of pretreatment SII determined by the receiver operating characteristics (ROC) curve. Survival analysis was calculated using the Kaplan-Meier method, and the Cox proportional hazards model was used for multivariate analysis. For these patients, the prognosis effects and the predictive value for survival of different SII levels combined with TNM staging were compared.Results:According to the ROC curves, the optimal cutoff value of SII before radiotherapy was 740.80. Based on this number, the patients were divided into a low-SII group (< 740.80, 150 cases) and a high-SII group (≥ 740.80, 98 cases). The objective response rate of the low-SII group was significantly higher than that of the high-SII group (86.0% vs 75.5%, χ2=4.39, P=0.036). The 1-, 3-, and 5-year overall survival (OS) rates of the low-SII group were 78.6%, 45.6%, and 32.3%, respectively. These rates were significantly higher than the corresponding rates of the high-SII group, which were 71.0%, 28.3%, and 16.4% ( χ2=11.22, P=0.001), respectively. Moreover, the 1-, 3- and 5-year progression-free survival (PFS) rates of the low-SII group were 67.0%, 36.9%, and 32.0%, respectively. Again, these rates were significantly higher than those of the high-SII group, which were 45.5%, 17.5%, and 12.5% ( χ2=15.38, P < 0.001), respectively. Multivariate analysis showed that TNM staging, treatment method, and SII were independent prognostic factors for OS and PFS ( HR=1.39-1.60, P<0.05). Patients with low SII and early clinical staging had a better prognosis than other subgroups ( χ2=13.68, 13.43, P=0.001). The area under curve (AUC) of SII combined with TNM staging (0.70) was higher than that of SII (0.63) and TNM staging (0.62) ( Z=2.48, 2.57, P < 0.05). Conclusions:Pretreatment SII has a high predictive value for the prognosis of esophageal cancer after radiotherapy, and higher SII indicates a worse prognosis. Thus, combining SII with TNM staging can improve the prediction accuracy of the prognosis of esophageal cancer patients.