RESUMO
Antitumor immunity plays an important role in the development of and protection against malignancy. In general, patients with cancer are known to be immunologically compromised. The objective of this study was to evaluate local immunity in squamous cell carcinomas (SCCs) of the tongue and lower lip by immunohistochemistry, using anti-CD3, -CD4, -CD8, -CD25 and -zeta antibodies. Immunoexpression at the invasive front was compared considering anatomical tumor location and metastasis. The CD4/CD8 ratio was calculated for each case and associated with the variables. CD3+, CD4+, CD8+ and CD25+ cell counts were higher in SCCs of the lower lip and anti-zeta immunostaining was more evident in non-metastatic cases. CD8+ and CD25+ cell counts were also significantly correlated with tumor location (p=0.004 and p=0.004, respectively), with the observation of a larger number of these cells in SCCs of the lower lip. The CD4/CD8 ratio showed no significant association with metastasis or anatomical location. In conclusion, the clinical behavior of the oral SCC cases studied might be partially related to the immunohistochemical profile of the inflammatory infiltrate present at the invasive front.