Cyclin D1 expression in oral squamous cell carcinomas: clinicopathologicalrelevance and correlation with p53 expression

The aim of the present study is to study the relationship between cyclin D1 and the clinicopathological features of oral squamous cell carcinomas, The cyclin D1 and p53 expression in oral squamous cell carcinomas from 56 pati ents (45 men, 11 women) was studied by immunohistochemistry using monoclona l antibodies, The correlation between cyclin D1 and the clinicopathological features of the oral cancers was evaluated. Cyclin D1 expression was found in 63% of oral squamous cell carcinomas; it was often weak but was more fr equently positive in high-grade lesions (P=0.019). The expression was posit ively correlated with p53 expression (P=0.06). Radiation therapy did not al ter the expression of either cyclin D1 or p53 proteins. Expression of these proteins was not related to the age, gender or survival of the patients, o r to stages of the tumors. The cyclin D1 expression was more frequently see n in patients with squamous cell carcinomas of oropharynx, palate, floor of mouth and gingiva. To conclude, cyclin D1 was frequently expressed in oral squamous cell carcinomas. This expression was related to the grade of the tumors and was not similar in various regions in the oral cavity, which may indicate the different tumor biology of cancers from these regions.