In <i>situ</i> proteomics of biomarker expression in epithelial ovarian cancer

5041 Background: Despite advances in treatment, 50% of women with advanced ovarian cancer still die of the disease. The poor clinical outcome underscores the need to develop novel strategies in the management of patients with advanced disease. Methods: A tissue array composed of 151 cases of advanced stage (stages III and IV) epithelial ovarian cancer treated postoperatively with paclitaxel and platinum-based chemotherapy was constructed. For protein analysis, a novel molecular-based quantitative method (AQUA) was used. Survival analysis was performed using X-tile. Primary end points were disease-free survival (DFS) and overall survival (OS). Correlation of protein expression levels with clinical-pathological variables was performed by chi-square test. Results: The following proteins were analyzed: Cell cycle regulators (p53, p21, pRb, p16), anti-apoptotic protein bcl-2, Epidermal Growth Factor Receptor (EGFR), phosphorylated Akt (p-Akt), phosphatase PTEN, cox-2 and β-catenin. High p53 expression was associated with improved DFS (p=0.0080) and OS (p=0.0003). High pRb expression was associated with improved DFS (p=0.009). High EGFR tumor expression was associated with inferior DFS (p=0.0046) and OS (p=0.0025). High tumor PTEN expression was associated with improved DFS (p=0.039) and OS (p=0.0025). High bcl-2 expression was associated with serous histology (p=0.014) and inferior DFS (p=0.0026). In multivariate analysis adjusting for known prognostic variables, the aforementioned markers retained their prognostic value. There was no association between p21, p16, p-Akt, cox-2 and β-catenin levels with survival times. Conclusion: AQUA is a promising molecular method for the identification of prognostic markers and targets for therapy in epithelial ovarian cancer. No significant financial relationships to disclose.