Foxp3 expression in patients with non-small cell lung cancer.

Abstract

e18059 Background: Lung cancer is rarely cured by the current therapeutic approaches. Although numerous studies have implicated Foxp3 positive T regulatory cells in cancer pathogenesis, the role of Foxp3 in lung cancer pathogenesis remains unknown. Methods: We determined Foxp3 expression, using immunohistochemistry in 44 NSCLC tissue specimens, 20 samples from adjacent non neoplastic lung parenchyma and 5 normal lung tissue specimens. Immunohistochemical reactivity was graded on a scale of 0–3 according to intensity of staining and percentage of immunopositive cells. Foxp3 expression in cancer cells was categorized in three groups (high vs median vs low) using as a cut-off point the 33rd and 66th percentile. The total score for each slide was the sum of the intensity and distribution (between 0 and 6). Statistical analysis was performed with SPSS 17.0. Results: Nuclear Foxp3 immunostaining was detected in al tissues assessed. Foxp3 expression levels were higher in neoplastic cells than in adjacent non neoplastic tissue and normal lung parenchyma. Moreover, Foxp3 expression in tumor cells correlated with lymphocytic Foxp3-immunopositivity and the presence of lymph node metastasis. Furthermore, Foxp3 lymphocytic expression was negatively associated with the age of the patients. Conclusions: Foxp3 is overexpressed in NSCLC cells and tumor infiltrating lymphocytes. Moreover, tumor Foxp3 expression correlates with lymph node metastasis while lymphocytic Foxp3 levels may be age-related.