Immunohistochemical Analysis of Natural Killer Cells and CD8+ T Lymphocytes in Lower Lip Squamous Cell Carcinoma

Abstract

Introduction: Inflammatory cells may influence the growth of malignant neoplasms through pro and anti-tumour effects. Natural Killer (NK) cells and cytotoxic T lymphocytes (CD8+) are the main effector cells against cancer. Aim: This study aimed to evaluate the presence of NK cells and CD8+ T lymphocytes in lower lip Squamous Cell Carcinomas (SCCs) and its correlation with clinico-pathologic parameters. Materials and Methods: Thirty two cases of lower lip SCCs were selected for clinical, morphologic and Immunohistochemical (IHC) assessment. NK cells (CD57+) and CD8+ T lymphocytes were identified and analysed quantitatively in five microscopic fields at the tumour invasion front using IHC markers. Results: All cases showed immunopositivity for both biomarkers. CD57+ and CD8+ T cells were more abundant in clinical stages I/II, nonmetastatic cases and low-grade malignancy tumours. However, there were no statistically significant differences. Similarly, no significant differences were found regarding local recurrence and clinical outcome. A strong positive correlation, statistically significant between CD57+ and CD8+ T cells was also observed (r=0.761, p<0.001). Conclusion: The high expression of CD57+ and CD8+ cells at the invasion front suggests they are involved in anti-tumour defense. However, these cells do not seem to effectively influence the progression of lower lip SCC. This may partially reflect the activities of other components of the immune system in the tumour microenvironment.

Keywords

• immunohistochemistry
• lip cancer
• t8 lymphocytes