The mechanisms of hormonal resistance includes intrinsic and acquired pathways: decreased ER expression accounts for intrinsic resistance and the increased receptor tyrosine kinase pathway relates to acquired resistance [40-42]. The investigators plan to analyze the mutation of PI3K/Akt and deletion of PTEN by sequencing in CTC (depending on numbers of cells, which in turn determines feasibility), in order to make a preliminary assessment of potential markers of response to pazopanib.