Correlations of Ki-67 and PCNA to DNA ploidy, S-phase fraction and survival in uveal melanoma.

In 79 patients with uveal melanoma, the tumours were investigated by DNA flow cytometry and immunohistochemical staining of PCNA and Ki-67. S-phase as a continuous variable was significantly correlated with Ki-67 (P = 0.033), but not with PCNA. DNA ploidy was not correlated with either of the two antigens. Ki-67 was significantly correlated with histopathological type (P < 0.001) and tumour size (P < 0.001). Large tumours and epithelioid cell type were associated with a high frequency of Ki-67 positive cells. A high level of Ki-67 positivity (> or = 6.5%) was also associated with a shorter survival (P = 0.0037), and when adjusted for DNA ploidy, histopathological type and tumour size, Ki-67 in the multivariate analysis remained an important prognostic factor (P = 0.017).