PROLIFERATING CELL NUCLEAR ANTIGEN COUNTS AS MARKERS OF CELL-PROLIFERATION IN HEAD AND NECK-CANCER

Proliferating cell nuclear antigen (PCNA) expression was investigated immunhistochemically in 53 squamous cell carcinomas of the head and ne ck. PCNA is a 36-kDa nuclear protein associated with the cell cycle. R esults were compared with Ki67 counts, with this latter marker used to demonstrate proliferative compartments. Overall, the PCNA and Ki67 la belling index showed a similar distribution pattern in normal and tumo r tissue. A strong correlation was found to histological differentiati on. There was no significant difference between PCNA and Ki67 counts ( r = 0.8), and PCNA immunostaining allowed assessment of proliferative activity in the head and neck cancers studied. The application of form alin-fixed, paraffin-embedded tumor material demonstrated the advantag e of this method and showed that it is an excellent alternative to Ki6 7 counts.