PCNA (proliferating cell nuclear antigen) is a 36 KD polypeptide that is maximally expressed in late G1 and S phases of the cell cycle, and correlates with DNA synthesis. Although the rates of proliferating tumor cells have been reported to be a marker for the malignant potential of several tumors, the clinical significance of proliferative activity in oral malignancies has not yet been fully investigated. This article presents the results of an immunohistological analysis of 22 squamous cell carcinomas of the tongue using anti-PCNA monoclonal antibody. The rate of PCNA positive cells was significantly related to clinical stage (p<0.05), histological grade (p<0.05), mode of invasion (p<0.05) and DNA ploidy (p<0.05). The percentage of PCNA positive cells was higher in cases with recurrence of the primary lesion than in cases without recurrence, although the difference was not statistically significant. On the other hand, a positive relationship was observed between the rate of PCNA positive cells and the incidence of cervical lymph node metastasis (p<0.05), with the incidence of lymph node metastasis being significantly (p<0.01) higher in cases with more than 30% PCNA positive cells than in those with less than 30% positive cells. In addition, the cumulative 3-years survival rate was significantly (p<0.01) worse in cases with more than 30% positive cells than in those with less than 30% positive cells.
These results suggest that the rate of PCNA positive cells can be utilized as a diagnostic parameter which predicts the propensity for cervical lymph node metastasis and the prognosis in squamous cell carcinomas of the tongue.
