An immunohistochemical study of proliferating cell nuclear antigen (PCNA) and MIB-1 in epithelial hyperplasia and dysplasia of the vocal cords

We investigated the proliferative activities in epithelial hyperplasia and dysplasia of the human vocal cords as precancerous lesions, using immunohistochemical staining with anti PCNA and MIB-1 (anti-Ki 67) monoclonal antibody. The series for this study consisted of nine patients with hyperplasia, 12 with mild dysplasia, ten with moderate dysplasia, eight with severe dysplasia, eight with vocal cord polyps, and 14 with invasive squamous cell carcinoma. The following results were obtained : 1) The mean PCNA labeling index was 1.12±1.05 (MEAN±STD%) in polyp, 4.88±2.02 in hyperplasia, 2.76± 1.76 in mild dysplasia, 3.80± 2.03 in moderate dysplasia, 6.12±3.01 in severe dysplasia, and 19.07±10.37 in invasive cancer. 2) The mean MIB-1 positive rates were 5.50±2.47 (MEAN±STD%) in polyp, 13.08±6.86 in hyperplasia, 16.55±7.34 in mild dysplasia, 15.94±6.73 in moderate dysplasia, 21.43±8.16 in severe dysplasia, and 41.48±14.05 in invasive cancer.