Significance of tumor associated tissue eosinophilia and other inflammatory cell infiltrate in early esophageal squamous cell carcinoma.

Tumor associated inflammatory cell infiltration plays an important role in the biological behavior of cancer as one of the carcinoma-stromal interactions. In this study, we characterized inflammatory cell infiltration on esophageal squamous cell carcinoma (SqCC) and correlated the findings with various clinicopathological factors, including clinical outcome of the patients, in order to study its biological significance. We examined 35 cases of surgically resected early esophageal SqCC or carcinoma with invasion limited to the submucosal layer. We evaluated the abundance of CD4+ T-cell, CD8+ T-cell, B-cell, plasma cell, CD68+ macrophage, neutrophil and eosinophil in the stroma adjacent to the tumor and correlated these findings with clinicopathological factors. The cases without LN metastasis had a significantly larger number of tumor associated eosinophils than those with LN metastasis. Primary lesions in cases without LN metastasis tended to demonstrate more CD68+ macrophage infiltration than those with LN metastasis, but the difference did not reach statistical significance. In addition, the cases with more than 50 eosinophils and macrophages per 10 high power field in the primary lesion demonstrated a significantly smaller incidence of LN metastasis than those with less than 50 eosinophils and macrophages per 10 high power field. Thus tumor associated tissue eosinophila, also known as TATE, is considered to be involved in the biological behaviour of early esophageal SqCC, especially in their metastatic potential.