Cyclin D1 expression in oral squamous cell carcinoma and verrucous carcinoma: correlation with histological differentiation.

OBJECTIVE: To assess the expression of cyclin D1 in oral squamous cell carcinoma (OSCC) and verrucous carcinoma (VC), to compare its expression in both of these carcinomas, and to investigate the possible correlation of cyclin D1 expression in different histological grades of OSCC.

STUDY DESIGN: Paraffin embedded tissues from 71 cases of OSCC and VC were studied immunohistochemically. Expression of protein was correlated between the 2 entities and in different grades of OSCC.

RESULTS: Cyclin D1 overexpression was seen in 29 cases (70.7%) of OSCC and in 19 cases (63.3%) of verrucous carcinoma. Statistical significance at the 5% level was observed for cyclin D1 expression between all categories of squamous cell carcinoma (SCC), that is, between well-differentiated and moderately differentiated carcinomas, and between moderate and poorly differentiated carcinomas, and well and poorly differentiated squamous carcinomas. No statistical significance was observed in cyclin D1 expression between SCC and oral verrucous carcinoma; however, statistical significance was seen between oral VC and poorly differentiated squamous cell carcinoma.

CONCLUSION: Increased expression of cyclin D1 significantly correlated with lack of differentiation in these malignant epithelial neoplasms.