Proliferating activity of biopsied specimens from 27 cases of laryngeal carcinoma was studied immunohistochemically using anti proliferating cell nuclear antigen (PCNA) antibody. PCNA labeling index was defined as percentage of the labeled cells in tumor tissue. PCNA labeling index was measured and related to histological and clinical findings. Results :
1) A positive correlation (p<0.01) was found between the PCNA labeling index and the mitotic index.
2) The PCNA labeling index was significantly different between T1, 2 group and T3, 4 group (p<0.01).
3) Many cases of poor prognosis were found in the cases showing a high PCNA labeling index.
4) In laryngeal carcinoma, the PCNA labeling index may be useful as an adjuvant diagnostic parameter for objective evaluation of the biological malignancy referred to as the proliferating activity.
