Abstract 4645: CIP2A is a marker of reduced survival in serous ovarian cancer patients

Abstract

Abstract Cancerous inhibitor of PP2A (CIP2A) is a recently identified oncoprotein, but its role in ovarian cancer is not known. We analyzed CIP2A protein expression in 562 consecutive serous ovarian cancer patients, of which 524 were scored successfully and analyzed for presence of CIP2A immunopositivity using tissue microarrays. The association of CIP2A expression with survival was evaluated according to the Kaplan-Meier method. We found strong CIP2A positive immunostaining in 212 (40.4%) specimens, 222 (42.4%) were weakly positive, while the rest (n = 90, 17.2%) were immunonegative for CIP2A protein. Our results demonstrate that CIP2A immunopositivity is a marker of reduced overall survival in ovarian cancer patients (P < 0.0001). In addition, positive CIP2A expression was significantly more frequent in specimens with high grade (P < 0.0001), advanced stage (P = 0.0005), aberrant p53 immunoreactivity (P < 0.0001), high proliferation index (P < 0.0001), and aneuploidy (P = 0.001). Interestingly, in subgroups of patients with favorable clinical factors (i.e. low stage and optimal debulking surgery) CIP2A expression was strongly associated with reduced survival (P < 0.0001 for both parameters). This shows that CIP2A could be used to predict biological behavior in the group of patients with otherwise favorable prognosis. In conclusion, our results show that CIP2A protein expression is a novel marker of reduced survival in patients with serous ovarian carcinoma. Furthermore, these results suggest that CIP2A characterizes the aggressive type of this disease even within subgroups with initially favorable prognosis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4645.