Roles of FoxP3-positive Regulatory T Cells in Lymphoid Follicle Formation Associated with Lung Squamous Cell Carcinoma

Background：We previously reported that lymphoid follicle formation by tumor infiltrating lymphocytes（TILs）is a negative predictor of prognosis in patients with lung squamous cell carcinoma（SCC）following surgery. However, the roles of FoxP3⁺/CD4⁺/CD25⁺-regulatory T cells（Tregs）in formation of lymphoid follicles as well as survival remain unclear.Methods：Specimens obtained from patients during resection of lung SCC were examined for lymphoid follicle formation and subjected to immunohistochemistry analysis for the presence of TILs.Results：The appearance of Tregs was correlated with lymphoid follicle formation（p＝0.001）. Univariate analysis also showed that Tregs tended to be correlated with overall survival（p＝0.097）, whereas multivariate analysis revealed that lymphoid follicle formation（p＝0.042）and pleural invasion（p＝0.031）were independent prognostic factors related to overall survival, while the appearance of Tregs was not.Conclusion：Treg appearance was correlated with lymphoid follicle formation. That lymphoid follicle formation, rather than appearance of Tregs, is a predictor of patients survival following surgery for lung SCC