Background/aims: Soluble interleukin-2 receptor (sIL-2R) is a useful biomarker for the management of hematologic malignancies. We determined the significance of serum sIL-2R levels in patients with squamous cell carcinoma of the esophagus.
Methodology: The correlation between serum sIL-2R levels and a variety of clinicopathologic factors in 51 patients with squamous cell carcinoma of the esophagus was evaluated. We also investigated the expression of IL-2R in the resected specimen using immunohistochemical staining.
Results: Expression of IL-2R was detected in primary esophageal carcinoma cells as well as infiltrating mononuclear cells. Serum sIL-2R levels in the 51 patients with esophageal cancer were significantly higher than those in the 18 healthy volunteers (p < 0.01). Multivariate analysis showed that pM, tumor size, and lymph node metastasis was significantly correlated with serum sIL-2R levels. Univariate analysis demonstrated that tumor size, pM, pTNM stage, and resectability were parameters which were significantly correlated with serum sIL-2R levels. There was no relationship between serum sIL-2 levels and tumor depth, lymph node metastasis, pT, histologic type, or curability.
Conclusions: These results suggest that the serum sIL-2R levels may be an indicator of the extent of disease and resectability in patients with esophageal squamous cell carcinoma. Immunohistochemical staining suggests that esophageal cancer cells and infiltrating mononuclear cells may be the source of sIL-2R in the serum.