Immunohistochemical expression and evaluation of cyclin D1 and minichromosome maintenance 2 in oral squamous cell carcinoma and verrucous carcinoma

BACKGROUND: The study of cell proliferation is important for assessing the tumor behavior, prognosis and patient survival of oral carcinomas. As literature search did not reveal sufficient studies of immunohistochemical expression of cyclin D1 and minichromosome maintenance 2 (MCM2) in oral squamous cell carcinoma (OSCC) and verrucous carcinoma (VC), the present study was undertaken. MATERIALS AND METHODS: The study group included 20 cases of histopathologically diagnosed OSCC, 10 cases of VC and 10 cases of normal mucosa (NM). All samples were evaluated for the expression of cyclin D1 and MCM2 using standard Immunohistochemistry (IHC) procedure. The present study involved both qualitative and quantitative analyses. Qualitative analysis was done by evaluation of intensity and area of staining. Quantitative analysis was done by calculating the percentage of positively stained cells and assessing the labeling index (LI). Data obtained were subjected to statistical analysis using SPSS statistical package (version 23.0). RESULTS: On evaluating and comparing the intensity of staining and area of staining of cyclin D1 and MCM2 between the study groups, statistically significant values (P < 0.05) were obtained using Kruskal–Wallis ANOVA. Comparison of LI of cyclin D1 and MCM2 in NM, OSCC and VC statistically significant results (P < 0.05) was obtained using Mann–Whitney U-test. Mean LI of MCM2 was found to be significantly higher than mean LI of cyclin D1 in all the study groups. CONCLUSION: From the present study, we conclude that MCM2 has the potential to serve as a novel cell proliferation biomarker in OSCC and VC when compared to cyclin D1.