Prognostic value of preoperative serum immunosuppressive acidic protein in patients with esophageal squamous cell carcinoma

Immunosuppressive acidic protein (IAP) is a potent biological marker of immunological surveillance in patients with malignant tumors. The aim of this study was to analyze the clinicopathologic significance of IAP in patients with esophageal carcinoma. Preoperative serum IAP concentration was measured by enzyme-linked immunosorbent assay in 115 patients with primary esophageal squamous cell carcinomas. The associations between clinicopathologic factors, C-reactive protein (CRP) values and IAP concentration were determined. Prognostic values were determined by multivariate analysis using Cox's proportional hazards model. The IAP concentration is significantly higher in patients with stage II-IV cancers than in those with stage I cancer. Significant differences in IAP concentration were observed depending upon tumor size, tumor depth, lymph node status and CRP values. A high IAP concentration, more than 500 mug/mL, was an independent prognostic factor. Thus, a high IAP concentration is associated with tumor progression and poor survival in patients with esophageal squamous cell carcinoma.