Immunohistochemical detection of eosinophilic infiltration in pulmonary adenocarcinoma

OBJECTIVES: Tumor-associated eosinophils play an important role in the biological behavior of cancer. We have detected eosinophilic infiltration immunohistochemically in tissue specimens from patients with pulmonary adenocarcinoma and assessed its association with the prognosis. MATERIALS AND METHODS: Utilizing the monoclonal antibody for EG2 thought to be a specific marker for eosinophils, the authors quantified eosinophil infiltration immunohistochemically in patients with pulmonary adenocarcinoma to investigate the relationship between EG2- positive cell counts and the prognosis. RESULTS: A significant difference in the rate of patient survival was detected between patients whose tumors had high EG2-positive cells and patients whose tumors had low EG2-positive cells overall (p=0.0086). Multivariate analysis also showed that eosinophils were significantly related to survival (p=0.044). CONCLUSION: These data indicate that eosinophilic counts utilizing the monoclonal antibody EG2 serve as a useful independent prognostic marker in pulmonary adenocarcinoma.