Expression of cyclin D1 and Ki-67 in squamous cell carcinoma of the oral cavity: clinicopathological and prognostic significance

The prognostic and clinicopathologic significance of cyclin D1 and Ki-67 expressions was studied in oral squamous cell carcinomas. We performed an immunohistochemical study to determine the level of expression of cyclin D1 and Ki-67 labelling index in tumor specimens obtained from 35 patients, of whom 14 died as a result of recurrent disease, and 20 were free of recurrence at the end of the follow-up period. Overexpression of cyclin D1 was significantly associated with regional lymph node metastases (P=0.00005) and advanced tumor stage (P=0.0007). The relative risk for nodal metastases in the cases that overexpressed cyclin D1 was 2.6. The Ki-67 labelling index was significantly (P=0.001) higher in tumors with poor histologic grade of differentiation. Our results showed that cyclin D1 is a useful prognostic factor, and suggested it could be a marker to help determine the appropriate treatment for patients with oral squamous cell carcinoma. Cyclin D1 and Ki-67 overexpression were positively correlated.