Proliferating cell nuclear antigen (PCNA) in ovarian carcinoma and its relation to lymph node metastasis and prognosis

Abstract

To investigate expression of proliferating cell nuclear antigen (PCNA) in ovarian epithelial cancer and its relation to lymph node metastasis, second-look laparotomy (SLL) and prognosis. Monoclonal antibody PC10 was used to stain PCNA in archival paraffin-embedded tissues. PC10 immunostaining was performed successfully in all 74 primary and 31 intraperitoneal metastatic tumors. The expression of PCNA was significantly elevated in 31 metastatic tumors compared with their primary tumor from the same patient (7.94 vs 6.89, P = 0.042). The expression was more marked in bilateral than in unilateral ovarian cancer but it was not associated with lymph node metastasis, clinical stage, histologic grade and subtype. In 28 patients with stage III ovarian cancer undergone SLL, the mean immunoreactive score (IRS) of PCNA of the primary tumor was significantly higher in patients with negative SLL than in those with positive SLL (7.59 vs 6.10, P = 0.03). Since chemotherapy was performed following surgical debulking, negative SLL more frequently seen in patients with high PCNA expression might suggest better chemotherapeutic sensitivity due to higher proliferation fraction of tumor cells. Univariate analysis of survival indicated that the overall survival was inversely associated with the level of PCNA expression, while multivariate analysis with Cox's model showed that independent prognostic factors were the residual tumor after primary debulking (P < 0.001) and clinical stage (P < 0.05), followed by PCNA expression (P = 0.09). The expression of PCNA may be useful in predicting prognosis, but is not correlated with lymph node metastasis.