DNA CONTENT AND PCNA IMMUNOREACTIVITY IN ORAL PRECANCEROUS AND CANCEROUS LESIONS

Thirty-three dysplastic lesions showing varying degrees of atypia loca ted in the oral cavity and 83 squamous cell carcinomas located in the oral cavity and tongue (n=56) or in the lips (n=27) were analysed by m eans of proliferating cell nuclear antigen (PCNA) immunoreactivity and image cytometric DNA measurements. The results show that in dysplasti c lesions increasing cellular atypia correlated to elevated proliferat ive activity and aneuploidy occurring in the basal cell layers. In hig hly differentiated squamous carcinomas increased PCNA immunoreactivity and aneuploidy was preferentially observed focally (grade 1 tumours) or in the invasive zones (grade 2 tumours). In contrast, more poorly d ifferentiated carcinomas (grade 3 and 4 tumours) showed strongly eleva ted proliferative activity and aneuploidy throughout the entire tumour mass.