High CD3+ lymphocytes, low CD66b+ neutrophils, and scarce tumor budding in the invasive front of lip squamous cell carcinomas

Abstract

Objective: This study aimed to evaluate tumor budding (TB) and quantify the neutrophilic and lymphocytic infiltration in the invasive front of lip squamous cell carcinomas. In addition, the associations between these features and the histopathological grading in the invasive front were analyzed.

Design: A total of 43 lip squamous cell carcinoma surgical specimens were included and classified in accordance with a histological invasive front grading system. Immunohistochemistry was performed for CD66b and CD3 for the evaluation of neutrophils and T lymphocytes, respectively, in the invasive front of the tumors. Tumor budding was evidenced by AE1/AE3 staining.

Results: Thirty-six (83.7%) of the tumors were well-differentiated tumors. Eleven (25.6%) of the cases exhibited high-intensity tumor budding. There were low neutrophil and high T lymphocyte infiltrations in the invasive front, leading to a low neutrophil/T lymphocyte ratio in the same region. Moreover, we found an association between tumor budding and the pattern of invasion, and between the CD3⁺ cell count and the inflammatory infiltrate (p < 0.05).

Conclusions: The low neutrophil and high T lymphocyte infiltration in the invasive front, and the few high-intensity tumor budding cases are in accordance with the histopathological features of well-differentiated lip tumors. If these characteristics remain in lip squamous cell carcinomas with more aggressive histopathological features, it deserves to be investigated.

Keywords: Lip cancer; Lymphocytes; Neutrophils; Squamous cell carcinoma; Tumor budding.