A Correlation Between the Expression of RNF43 Protein and Prognosis in Mucinous Ovarian Carcinoma

Background: Mucinous ovarian carcinoma (MOC) is an aggressive cancer with poor prognosis. Therefore, the prognostic prediction factor is important. The Ring finger protein 43 (RNF43) may be the new prognostic marker. Objective: To evaluate the expression of RNF43, and prognostic prediction of RNF43 protein in MOC. Material and Methods: The study population were patients diagnosed as MOC, between January 2005 and December 2014, selected from Songklanagarind Hospital, Thailand. All cases had paraffine-embed tissue of tumor. Immunostaining for RNF43 (clone ab217787-Abcam, USA) was performed and evaluated expression by one pathologist and one pathology resident. The expression of RNF43, clinical features and survival outcome were evaluated. Results: There were 104 cases, and all cases showed positive in cytoplasmic staining for RNF43, with high RNF43 expression being found in 86 cases (82.7%). Tumor stage and tumor recurrence were significantly related to RNF43 level of expression (p=0.02 and 0.04, respectively). Approximately 80% of the patients with high RNF43 expression were in the early stage and about 90% showed no tumor recurrence. Patients with high RNF43 expression had longer survival than patients with low RNF43 expression. However, RNF43 expression was not significantly correlated with survival outcome. Conclusion: MOC showed high expression of RNF43 protein, however, RNF43 expression is not an independent prognostic survival factor by multivariable analysis.