Vascular And Tumor Cell Expression Of Vegfr2 And Molecular Subtyping: An Innovative Biomarker Approach In Bladder Cancer.

497Background: Treatment approaches combining anti-angiogenic therapy with chemotherapy have shown promising clinical results in metastatic bladder cancer (BC). In order to interrogate the potential clinico-pathologic and molecular basis of these findings, we evaluated VEGFR2, vascular density and molecular subtyping in a series of BC patients. Methods: A custom-TMA with primary BC tissues from 117 patients (mean age 71 yrs; range 38-99 yrs; M:F = 83:34) treated at a single institution, was stained and scored (0-3) for CD34 (vascular density) and for VEGFR2 on tumor vessels and cells. CK5/6 and GATA3 IHC was scored by a pathologist to identify main molecular classes of BC. The association between clinico-pathologic variables, VEGFR2, CD34 and molecular subtypes was analyzed by Fisher’s exact test and ANOVA. Univariate and multivariate Cox proportional models were used for survival analysis. Results: Of 112 analyzable BC tissues, 41% were muscle-invasive (MIBC) vs. 56% non-muscle invasive (NMIBC) and 3% un...