514 Background: Statins (HMG CoA reductase inhibitors) are commonly used cholesterol-lowering agents that are noted to suppress tumor growth in several animal models, however clinical data for chemoprotective role of statins in breast cancer is conflicting. While some studies report reduced risk of breast cancer with lipid lowering drugs, others report an increased risk. We investigated the effect of statins on the development of breast cancer in the US female veteran population. Methods: The VISN 16 database, which contains clinical and demographic information about all veterans (>1.4 million patients) cared for in the South Central VA Health Care Network, was queried from Oct 1998 to June 2004. Retrospective case control design was used. Patients were placed in the statin users group if they were taking statins prior to the diagnosis of breast cancer but the dose, duration and type of statin used was not factored into the analysis. Statistical analysis was performed using SAS software version 9.0 (Chica...