Prognostic Significance of Phosphatase of Regenerating Liver-3 Expression in Ovarian Cancer

Phosphatase of regenerating liver-3 (PRL-3) is overexpressed in several human cancers and associated with tumor progression, invasion and metastasis. However, the correlation between PRL-3 expression and clinical outcome in ovarian cancer has not been studied. In the present study, we investigated the expression of PRL-3 in 119 ovarian cancers and 30 normal ovarian tissues by immunohistochemistry with an anti-PRL-3 mouse monoclonal antibody 3B6, and analyzed its relationship with clinicopathologic factors and survival. The results demonstrated that PRL-3 expression was significantly higher in ovarian cancers compared to normal ovarian tissues (P < 0.001). PRL-3 expression is not correlated with patient age, menstruation, tumor size, histological type, residual tumor, or other clinical findings. The patients with PRL-3-positive tumors had a significant poor prognosis than those with PRL-3-negative tumors. Univariate analysis identified PRL-3 expression as a poor outcome predictor (HR 1.925, 95% CI, 1.046–3.544, P = 0.035). Multivariate analysis indicated that PRL-3 expression was an independent prognostic factor of borderline significance (HR 1.695, 95% CI, 0.914–3.145, P = 0.094). Our results suggest that PRL-3 may serve as a valuable marker for diagnosis of ovarian cancer and as a potential independent prognostic factor for ovarian cancer.