THE PRESENCE OF P53 PROTEIN IN RELATION TO KI-67 AS CELLULAR PROLIFERATION MARKER IN HEAD AND NECK SQUAMOUS-CELL CARCINOMA AND ADJACENT DYSPLASTIC MUCOSA

Paraffin embedded material from 15 patients suffering from head and ne ck squamous cell carcinoma (HNSCC) bordered by dysplastic mucosal area s was immunohistochemically investigated for the presence of p53 prote in and Ki-67 proliferation marker. p53 protein was present in 9 cases (60%), invariably in invasive cancer areas as well as in adjacent non- invasive dysplastic mucosa. Only cells exhibiting atypia contained p53 protein. Ki-67 proliferation marker was present in the basal cells of the normal epithelium and more extensive in dysplasias and HNSCC. The presence of Ki-67 closely coincided with p53 protein in the 9 cases e xhibiting this. No differences in Ki-67 expression were found between p53 positive and negative cases. It is concluded that the appearance o f p53 protein occurs early in carcinogenesis but that cells also may s how increased proliferation without involving immunohistochemically de tectable alterations in the p53 gene.