Objectives: Progression of malignant neoplasias is accompanied by alteration of the extracellular matrix (ECM) composition. Tenascin is known as a member of the adhesion-modulating family of ECM macromolecules; thus its expression and distribution may have significant influence on tumor cell proliferation and invasiveness.
Study design: The present study was carried out to determine the distribution pattern of tenascin in laryngeal and hypopharyngeal cancer samples.
Methods: In double and triple immunofluorescent staining reactions the detection of tenascin was combined with labelings for cytokeratin (marker protein of epithelial cells), for CD-34 (endothelial cell surface glycoprotein), and for a reaction with Ki-67 monoclonal antibody (nuclear antigen in proliferating cells).
Results: In laryngeal cancers, in early stages of tumor growth a markedly enhanced production of tenascin at the tumor host interphase was observed. In the later stages of tumor progression, a high number of blood vessels located in the tumorous tissues were also strongly labeled for tenascin. Around these vessels a significant number of proliferating tumor cells could be detected. In contrast, in hypopharyngeal cancers this vasculature-associated staining pattern could be observed from the very early stage of tumor development. In laryngeal and in hypopharyngeal cancers, tenascin upregulation strongly correlated with metastasis formation, early tumor recurrence, and lethal outcome of the disease.
Conclusions: Clinical and immunohistologic data indicate that the accumulation of tenascin in the tumor blood vessels is an unfavorable prognostic indicator in laryngeal and hypopharyngeal cancers.