Clinicopathological Significance of Taz and VGLL1 Expression in Early Stage Ovarian Cancer. A study by Spanish Group for Ovarian Cancer Research (GEICO).

e16583 Background: The Hippo signaling pathway has emerged as an important regulatory pathway in cancer. Two final transducer effectors of this pathway are the oncoproteins TAZ and VGLL1. In breast cancer, the expression of these two proteins occurs mainly in triple negative tumors. The aim of this study is to analyze the role of TAZ and VGLL1 in ovarian cancer (OC). Methods: We studied a total of 212 FFPE samples belonging to the GEICO Early Stage (I-II) OC Registry. All cases were reviewed centrally by two independent pathologists after the evaluation of WT1, p53, p16, progesterone receptor and napsin A expression to confirm histological type. Final diagnosis was achieved by consensus and compared with diagnosis of origin (DO). TAZ and VGLL1 were evaluated by immunohistochemistry on tissue microarrays (TMAs) and their impact on prognosis was analyzed by log-rank tests being relapse free survival (RFS) the clinical endpoint. Results: OC were classified as following: high-grade serous (HGS, n = 44), low-g...