Difference in P57 Expression Among Four Histological Types of Epithelial Ovarian Carcinoma.

P57 is known to have anti-tumor activity through inhibition of cyclin-dependent kinases. We performed immunohistochemical analysis on expression of P57 in 92 cases of epithelial ovarian carcinoma (EOC), of which, 31, 14, 18 and 29 were diagnosed as serous, mucinous, endometrioid (EC) and clear cell carcinoma (CCC), respectively. Of 92 cases of EOC, 6 and 28 were positive for P57 in the nucleus and the cytoplasm, respectively. Five cases of 29 CCC (17.2%) were positive in the nucleus, which was significantly greater than in non-CCC (p = 0.03). In contrast, positive cases in the cytoplasm were significantly greater in EC (55.6 and 23.0% for EC and non-EC, respectively, p = 0.01). Expression patterns of nuclear and cytoplasmic p57 showed no correlations with clinical stage of EOC. Clinicopathological significance of P57 expression in EOC would need further investigation.