Comparison of p53, Ki-67, and CD44v6 expression between primary and matched metastatic lesions in ovarian cancer

Objective. Many studies have demonstrated that clinically evident tumor cells already carry multiple genetic alterations and further accumulation of genetic alteration causes tumor progression which plays a role in metastasis. Therefore, it could be expected that malignant potential in the metastatic site is more aggressive than that in the primary site. Using several immunohistochemical markers (p53, Ki-67, and CD44v6), we investigated an alteration of malignant potential. Methods. We immunohistochemically examined expression of p53, Ki-67, and CD44 in primary and metastatic lesions of ovarian cancer. Fifty-six samples of primary lesions and matched metastatic sites from 56 patients with primary epithelial ovarian cancers were included in this study. Results. In 16 cases (28%), the histological grade of the metastatic lesion increased. This difference was statistically significant (P = 0.0232). In 16 cases (28%), the expression of p53 increased in the metastatic lesions, in 5 pairs from negative to positive, whereas the case decrease in the metastatic lesions was only 1. This difference was statistically significant (P = 0.0046). There was no significant difference in Ki-67 labeling indices and expression of CD44v6 between the primary and matched metastatic lesions. The degree of p53 expression in the metastatic lesions significantly correlated with disease-free survival (P = 0.0482), whereas that in the primary lesions did not. Moreover, high p53 expression in the metastatic lesions significantly correlated with disease-free survival in multivariate analysis. Conclusions. The p53 expression in metastatic lesions may reflect an aggressive biologic behavior in ovarian cancer.