Background/aim: Lung cancer is rarely cured by current therapeutic approaches. Although numerous studies have implicated FOXP3 positive regulatory T-cells in cancer pathogenesis, the role of FOXP3 in lung cancer pathogenesis remains unkown.
Materials and methods: Using immunohistochemistry FOXP3 expression was determined in 44 NSCLC tissue specimens, 20 samples from adjacent non neoplastic lung parenchyma and 5 normal lung tissue specimens.
Results: FOXP3 immunostaining was always nuclear in both tumor and non-neoplastic adjacent tissues. FOXP3 was also detected at lower levels in normal bronchial epithelium. Moreover, FOXP3 expression in cancer cells correlated with lymphocytic FOXP3-immunopositivity and the presence of lymph node metastasis. FOXP3 lymphocytic expression was also negatively associated with the age of the patients.
Conclusion: FOXP3 is overexpressed in NSCLC cells and tumor-infiltrating lymphocytes. This study provides evidence that lymphocytic FOXP3 expression may be age related and that tumor FOXP3 expression is correlated with lymph node metastasis.