Study of Cyclin D1 Expression in Squamous Cell Carcinoma of Oral Cavity

Oral Cavity Squamous Cell Carcinoma (OSCC) ranks 6th most common cancer across the world. Cyclin D1 regulates G1 to S phase of cell cycle. Its uncontrolled expression leads to excessive cell proliferation and neoplasia. This makes Cyclin D1 a possible biomarker for early diagnosis and management strategies. Fifty oral cavity histopathology specimens (10 benign lesions and 40 OSCC) were evaluated in a teaching hospital. Cyclin D1 expression was studied. Statistical significance (p value of ≥ 0.05 were considered insignificant) was calculated by Chi-Square and Mann-Whitney Wilcoxon test. We observed 15 well-differentiated Squamous cell carcinomas (WDSCC), 15 moderately-differentiated squamous cell carcinomas (MDSCC), 10 poorly-differentiated squamous cell carcinomas (PDSCC) amongst our cases of OSCC. Common sites were buccal mucosa (47.5%), tongue (35%) and tonsillar area (5%). All OSCC showed positivity for cyclin D1; while benign lesions exhibited immunoreactivity to cyclin D1 with mild staining of only < 10% cells. High Labeling Index (score 4) was seen more in PDSCC (70%) as compared to MDSCC (6.6%), WDSCC (00%). PDSCC showed strong intensity in 80% cases while only 20% MDSCC and 0% WDSCC cases had strong staining. Increase in Cyclin D1 immuno-reactivity is associated with decrease in cell-differentiation. Cyclin D1 may be a target for molecular based therapy leading to improved prognosis in OSCC.