Immunohistochemical expression of TFIIH and XPF in oral tongue squamous cell carcinoma. 
The query for biomarkers that indicate tumor aggressiveness and the host's response to treatment is still one of the leading aims of cancer research.  To investigate a possible role for DNA nucleotide repair proteins in oral cancer behavior, this study evaluated the immunoexpression of the proteins TFIIH and XPF and its association with clinical, histological, and survival parameters in oral tongue squamous-cell carcinoma (OTSCC).  TFIIH and XPF immunoexpressions were evaluated in 82 cases of oral tongue squamous-cell carcinoma.  Tumor budding and depth of invasion were assessed for histopathological grading (BD model).  Tumor cells exhibited high expression of TFIIH and XPF, which was associated to nodal status; both proteins were not associated with other clinical parameters, histopathological grading or survival.  Tumor size, nodal status, tumor staging, and depth of invasion > 4 mm were significantly associated to disease-specific survival.  We have demonstrated that the overexpression of TFIIH correlates positively with node metastasis, while XPF correlates negatively with node metastasis; therefore, the expression of XPF and TFIIH had a potential value for predicting the progression of OTSCC patients.