Diagnostic clinical aids in oral cancer.

Conventional oral exploration (visual and palpation examination) constitutes the current gold standard for oral cancer screening, while biopsy and histopathological examination represents the indispensable study for the detection of cases in patients with an identified lesion. Imaging techniques (DPT, CT, and MRI) are frequently used to supplement the clinical evaluation and staging of the primary tumour and regional lymph nodes. There are also a number of techniques that may contribute to the diagnosis of oral cancer: toluidine blue test has been used as a diagnostic aid for the detection of oral cancer over decades. Recently developed light-based detection systems have progressively improved in sensitivity and specificity, but multicentre controlled studies conducted by general dental practitioners must be designed in order to justify their application. The oral brush biopsy appears to overestimate dysplastic lesions and produces a high number of false-positive results. In the near future, immunological and biochemical alterations in the serum (e.g., circulating immune complexes, carcinoembryonic antigen, squamous cell carcinoma associated antigen, inhibitor of apoptosis, cytokeratin fragments, and annexin A1) as well as specific saliva analysis (e.g., cancer related cytokines, metalloproteinases, epithelial tumour markers, DNA promoter hypermethylation, and saliva micro-RNA) may become important tools for the detection of oral cancer.