Prognostic biomarkers for squamous cell carcinoma of the mouth

Squamous cell carcinoma of the mouth is the most common head and neck tumor, and is often associated with regional lymph node metastasis, poor prognosis and reduced survival rates. It mainly affects middle-aged men who use tobacco. Low oxygen tension plays an important role in the self-renewal, metastatic potential and resistance to therapy of cancers. To adapt to the hypoxic environment, neoplastic cells activate hypoxia-induced factor-1 alpha (HIF-1 alpha), which can facilitate invasion and metastasis. In addition, human THY-1 (CD90), a cell surface protein expressed on stem cells, mediates cell adhesion, and appears to promote development in some malignant tumors. This study sought to analyze the expression of HIF-1 alpha and CD90 proteins in squamous cell carcinoma of the mouth and metastatic lymph nodes, in the intratumoral region and at the invasion front, using immunohistochemistry. Thus, it was possible to observe that the hypoxic microenvironment can facilitate regional metastasis and that CD90-positive microvessels and mast cells activated by this pathway seem to promote tumor progression.