Serum interleukin-8 and its relationship to tumor burden and treatment response across malignancies of multiple tissue origins.

e22135 Background: IL-8 is a chemokine that is produced by malignant cells of multiple cancer types and that exerts various functions in shaping pro-tumoral vascularization and inflammation/immunity. We evaluated sequential levels of serum IL-8 in preclinical tumor models and in patients with multiple tumor types, at baseline and following anticancer treatment to assess its ability to estimate tumor burden. Methods: IL-8 levels were monitored by sandwich ELISAs in cultured tumor cell supernatant, tumor-xenografted mice serum and in 119 cancer patients’ serum and urine samples, at baseline and following anticancer treatments. We correlated IL-8 levels with baseline tumor burden and with treatment induced changes in tumor burden, as well as with cancer prognosis. Results: IL-8 concentrations correlated with the number of IL-8 producing tumor cells in culture. In xenografted neoplasms, IL-8 serum levels rapidly dropped after surgical excision, indicating an accurate correlation with tumor burden. In patients...