Proliferating cell nuclear antigen in needle biopsy specimens of prostatic carcinoma

The expression of proliferating cell nuclear antigen (PCNA) was immunohistochemically determined using a monoclonal antibody PC10 in 54 prostatic carcinoma samples. The samples were taken from needle biopsy specimens which had been paraffin-embedded after routine fixation with 10% formaldehyde solution (formalin) for less than 24 h. The PCNA index was calculated as the percentage of positive tumor cell nuclei. There was a significant difference in the PCNA index according to the growth pattern (p < 0.001), nuclear anaplasia (p < 0.001) and T stage (p < 0.01). Regarding the growth pattern, solid carcinomas showed a significantly higher PCNA index than did either separate gland carcinomas (p < 0.05) or trabecular/fused gland carcinomas (p < 0.05). The PCNA index correlated closely with either the nuclear anaplasia or T stage, and increased in conjunction with the increased nuclear anaplasia (rs = 0.641; p < 0.001) or T stage (rs = 0.435; p < 0.01). The patients in the high PCNA index (> or = 15%) group showed a significantly worse survival than did those in the lower PCNA index group (p < 0.01), and multivariate analyses indicated that the PCNA index had an independent prognostic significance. These results suggest that the PCNA index, as determined by PC 10 on needle biopsy specimens of prostatic carcinoma, can thus be an objective and quantitative means for evaluating the biological malignancy of prostatic carcinoma.