Serum interleukin-8 as a potential diagnostic biomarker in esophageal squamous cell carcinoma.

Abstract

Esophageal squamous cell carcinoma (ESCC) has poor prognosis mainly due to the difficulty of making early diagnosis. Therefore, novel biomarkers are critically needed. We aimed to investigate the diagnostic value of serum interleukin-8 (IL-8) in ESCC. Data mining of TCGA was used to analyze expression level of IL-8 mRNA in esophageal carcinoma. Serum levels of IL-8 were measured in 103 ESCC patients and 86 normal controls by ELISA. Receiver operating characteristic (ROC) curve was used to evaluate its diagnostic accuracy. IL-8 mRNA expression level and serum IL-8 concentration were both statistically higher in patients than normal controls (P< 0.001). ROC curve demonstrated that the optimum diagnostic cut-off for serum IL-8 was 80.082 pg/mL, providing an area under the curve (AUC) of 0.694 (95% CI: 0.620-0.768), with specificity of 86.0% and sensitivity of 42.7%. The AUC for early-stage ESCC was 0.618 (95% CI: 0.499-0.737), with sensitivity of 35.3% and specificity of 86.0%. Kaplan-Meier analysis and the log-rank test indicated that IL-8 may not be a prognostic predictor for ESCC. Serum IL-8 was highly expressed in ESCC patients and may be a potential marker for early diagnosis of ESCC.