Expression of p53/Ki67 in Toluidine Blue/Vinegar Positive Oral Cancer Lesions

Oral cancer is one of the most common cancers in Thailand. A number of techniques have been developed to supplement clinical examination for oral malignancy. One reagent that has been widely used is toluidine blue. Another interesting screening reagent is 3-5% acetic acid which has been used for cervical cancer screening. A clinical screening technique would be more trustworthy if it is correlated with cellular markers used for cancer detection. Objectives: This study's aim was to investigate the association between clinical screening using vinegar (5% acetic acid) and/or toluidine blue and the expression of proliferation marker, Ki67 and the tumor marker, p53. Methods: The study included 87 participants suspected of having oral squamous cell carcinoma. Vinegar and/or toluidine blue were applied to the lesions, followed by incisional biopsy. The specimens were microscopically examined for pathological diagnosis and underwent immunohistochemical investigation for Ki67 and/or p53. Results: The results revealed that the sensitivity and specificity of oral cancer screening using vinegar were 85% and 82% respectively; whereas the sensitivity and specificity of using toluidine blue were 93% and 46%, respectively. When the specimens of the first 30 patients were used to examine the association between clinical screening using vinegar and expression of p53, it was found that there was a statistically significant association (p=0.000). There was also a statistically significant correlation between the use of vinegar and the expression of Ki67 (p=0.019). Although there is a difference in the expression of p53 between specimens that were positive and negative to toluidine blue, the correlation did not reach a significant level. Conclusions: The results of this study suggest that vinegar is an alternative for oral cancer screening. The results of clinical screening using vinegar correlated with the expression of p53 and Ki67 at the cellular level.