Association of downregulation of toll-like receptor 3 (TLR3) expression with aggressive breast cancer (BC).

11035 Background: Inflammation in the tumor microenvironment plays a key role in human breast cancer. We previously showed that a high proportion of alternatively-activated, tumor-associated macrophages (M2) are associated with increased microvessel density (MVD) and worse outcomes in BC. The anti-tumor effect of TLR3 is well recognized. To our knowledge, there are no studies evaluating TLR3 expression and characteristics of inflammation in primary breast tumors. Methods: 48 breast tumors were obtained from the University of Chicago Breast Cancer SPORE tissue bank under IRB approved protocols. Tissue microarrays were constructed and molecular subtypes assigned based on immunohistochemical (IHC) staining into: luminal A, luminal B, HER2-like, and basal-like. Macrophage density was determined using double staining with CD68/CD163. MVD was measured by IHC using anti-CD34. Staining quantification was done by a pathologist. To evaluate the association between M2 macrophages, TLR3 and MVD, Spearman's rho correl...