Prognostic value of cyclin D1, p27, and p63 in oral leukoplakia

Studies on the expression of genes regulating cell proliferation and apoptosis are essential to help better understand the severity and possible malignant transformation of oral leukoplakia.

The characteristics of cyclin D1, p27, and p63 were investigated in this microscopic study, complementing our previous results with Ki67, p53, and the apoptosis index. Clinical and histologic as well as immunohistochemical studies were carried out on oral leukoplakia of 18 patients. Homogenous, or non-homogenous (nodular or speckled) and erythroleukoplakia were determined clinically. Pathologic classification was performed according to the degree of dysplasia. Immunoperoxidase reaction for cyclin D1, p27, and p63 was carried out on the biopsy specimens and the positivity of the reactions was calculated for 1000 epithelial cells.

The expression of cyclin D1 increased in parallel with the severity of leukoplakia. The p27 index was 14-16% in homogenous and nodular leukoplakias but it was substantially lower to 1-2% in erythroleukoplakia. The p63 index was 10% in homogenous, 5% in nodular or speckled, but nearly 20% in erythroleukoplakia, on the average.

These results suggest that the characteristic expression of cyclin D1, p27, and p63 in various forms of leukoplakia may be of prognostic value.