We immunohistochemically studied proliferating cell nuclear antigen (PCNA) in 25 oral squamous cell carcinomas. PCNA-positive cells were detected in all formalin fixed, paraffin embedded specimens. The results were as follows:
1. The PCNA-positive rate in the group with cervical lymph node metastasis was significantly higher than in the group with no metastasis (p<0.05).
2. The PCNA-positive rate in the group with a clinical responce of no change was significantly higher than in the group with a partial response (p<0.01).
3. The PCNA-positive rate in specimens obtained during operation was significantly lower than those obtained by biopsy (p<0.05).
These results suggests that the PCNA-positive rate may be a useful factor in selecting the most effective type of antitumor therapy.
