[Contribution of proliferating cell nuclear antigen to prognostic evaluation of carcinomas of the maxillary sinus].

Proliferating cell nuclear antigen (PCNA) is a nuclear protein, synthesized in the late G1 and S phases of the cell cycle. Therefore, it is considered to be closely related to cell proliferation. The contribution of PCNA to prognostic evaluation of the disease was investigated in 42 squamous cell carcinomas of the maxillary sinuses, retrospectively. Histological sections were prepared by formalin-fixation, paraffin-embedding and staining with monoclonal antibody to PCNA (DAKO, PC10) using the Avidin-biotin peroxidase complex method. The percentage of tumor cells with positive staining for PCNA ranged from 26.3 to 92.3% (average; 61.7%). In order to evaluate PCNA in terms of prognosis, five-year survival rates in the following two groups were compared. One included cases with a PCNA positive rate above the mean level and the other, those below the mean level. Five year survival rate was 30.4% in the group with a higher positive rate, but 42.1% in the group with the lower rate. However, the difference in survival rate between the two groups was not statistically significant. In addition, no correlations either between the rate of PCNA positivity and T-classification of tumors or between the degree of tumor cell differentiation and metastasis to neck lymph nodes were obtained. Further study is necessary to evaluate PCNA as a prognostic marker in human malignancy.