The Role Of Macrophages In Docetaxel (Dtx) Resistance In Castrate-Resistant Prostate Cancer (Crpc).

e22175 Background: DTX improves symptoms and survival in advanced CRPC, however ~ 50% of patients have chemoresistant disease. Given the toxicity of cytotoxic treatment in this population, there is an urgent need for early chemoresistance markers, a greater understanding of chemoresistance mechanisms and the development of new therapies. This study examined whether early changes in cytokine levels predict chemoresistance and explored the role of macrophages in cytokine generation and chemoresistance in vitro. Methods: 28 cytokines were measured pre/post cycle 1 of chemotherapy from 59 men with metastatic CRPC. Cytokine levels were correlated with PSA response and OS. DTX sensitive PC3 and DTX resistant PC3Rx cells were cultured alone and in coculture with U937 monocytes +/- DTX treatment. Conditioned media (CM) was analysed by a 36 cytokine array panel and by ELISA for MIC1. CM from U937 cells exposed to DTX was used to treat PC3 cells combined with escalating DTX doses. Results: Change in the levels of 1...