Antioxidant enzymes in oral verrucous carcinoma

Background: Verrucous carcinoma is a non-metastasizing variant of welldifferentiated squamous cell carcinoma, which has been associated with reactive oxygen species generated by betel quid chewing. Salivary antioxidant systems have been suggested to play a protective role in reducing the oxidative damage. Herein, we investigated the difference of the enzymatic antioxidant system expressions in oral verrucous carcinoma and oral squamous cell carcinoma. Methods: The enzymatic antioxidant system expressions, including manganese superoxide dismutase, glutathione peroxidase, and catalase were evaluated by immunohistochemistry in a series of 202 surgically resected oral squamous cell carcinoma and 20 oral verrucous carcinoma specimens, using tissue microarray slides. Results: The immuno-staining intensities of superoxide dismutase and glutathione peroxidase were strongest in the oral squamous cell carcinoma group than in verrucous carcinoma. The catalase expression showed no difference between different pathological groups. Conclusions: The different degrees of superoxide dismutase and glutathione expressions in verrucous carcinoma and squamous cell carcinoma may be helpful for pathologists to differentiate these two entities, especially between oral verrucous carcinoma and well differentiated oral squamous cell carcinoma.