Expression of CD44 isoforms in squamous cell carcinoma of the border of the tongue: A correlation with histological grade, pattern of stromal invasion, and cell differentiation.

Abstract

Oral squamous cell carcinoma is a frequent disease with reserved prognosis, where the routinely evaluated morphological features lack a major correlation with prognosis. In order to assess the potential value of the immunoexpression of CD44 isoforms v3, v4-5, and v6, we studied it in a series of 56 consecutive cases of squamous cell carcinomas of the border of the tongue. All the histological (World Health Organization grade, Bryne score, degree of keratinization, and pattern of stromal invasion) and immunohistochemistry (using monoclonal antibodies to CD44v) results were exclusively assessed at the deep invasion front of the neoplasms. Downregulation of CD44v was defined by focal or irregular staining of < 10% of the cells at the deep invasive front. There was downregulation of CD44v3 in 37.5% of the cases, CD44v4-5 in 67.9%, and CD44v6 in 33.9%, occurring mostly in cases with low Bryne scores and graded as well-differentiated according to the WHO classification. Downregulation of CD44v was found to correlate with cell differentiation, tumor grade, and the pattern of neoplastic invasion. Our findings in the present series point to the consideration that CD44v pattern and intensity of immunoexpression in the deep invasive front of squamous cell carcinoma of the tongue are mostly related to tumor grade, the features of stromal invasion, and to the presence of cervical lymph node metastases.