MCM 3 could be a better marker than K i‐67 for evaluation of dysplastic oral lesions: an immunohistochemical study

Background The aim of this study was to identify the expression of MCM 3, K i‐67 and p27 in normal mucosa, leucoplakia and oral squamous cell carcinoma ( OSCC ) and determine whether altered expression could serve as a prognostic marker of a malignant progression of dysplastic lesions. Methods The samples were collected from 37 patients with oral leucoplakia (13 with mild dysplasia – MLD , 12 with moderate dysplasia – MD and 12 with severe dysplasia – SD ). Eleven samples of mouth floor mucocele ( M ) and 50 floor mouth and tongue samples OSCC of untreated patients were included in this study. Immunohistochemical expression of MCM 3, K i‐67 and p27 of all the groups was analysed. K ruskal– W allis and D unn's test were used to determine differences among groups, and a P earson's correlation test was used to evaluate the correlation between the proteins. Results K i‐67 expression was higher in OSCC than M ( P  < 0.001) and MLD ( P  < 0.01) groups, and there was a lower expression in M compared with MD and SD ( P  < 0.05). Regarding p27, its expression was lower in OSCC compared with M , MD and SD . MCM 3 expression was lower in M compared with SD and OSCC ( P  < 0.001), and MLD showed a lower expression when compared SD ( P  < 0.01) and OSCC ( P  < 0.001). Moreover, a better correlation was observed between the proteins MCM 3 and p27 than between K i‐67 and p27 proteins when all lesions were examined together. Conclusions This study showed that MCM 3 could be a better marker than K i‐67 for evaluation of dysplastic oral lesions.