Abstract 1713: Immunomodulatory effect of statins on Tregs within human colorectal cancer is determined by the stage of disease

Abstract Colorectal cancer (CRC) is a public health problem worldwide and in Jordan. Statins are best seller cholesterol lowering agents. Beyond their cholesterol-lowering effects, statins use has been reported to reduce the risk of several malignances including CRC. This study aimed to assess the effect of statins on CRC risk by studying cellular infiltration of Tregs into CRC tissues and their effect on Transforming growth factor beta 1 (TGF-β1) level and angiogenesis. A total 47 specimens (25 statins users, and 22 statins nonusers) of CRC were used. Immunohistochemical analysis was performed to study Tregs infiltration by studying their specific marker fork head transcription factor (FOXP3), and angiogenesis by studying CD31 positive blood vessels. TGF-β level was measured using commercial ELISA kits. Results revealed that in case of statins use was associated with more Tregs infiltration, more angiogenesis but no difference in TGF-β1 content in tumor tissue. When further categorized analysis according to stage of disease, angiogenesis effect was more pronounced in early disease and wasn't significant in advanced disease.In addition, more Tregs infiltration was significantly noticed in advanced disease but not in early disease. Same stage-dependence wasn't notices with TGF-β1. Since statins are associated with reduced risk of death in colorectal cancer patients, we could suggest some immunologic mechanism for that. Tregs infiltration into tumor and reduction of inflammation at tumor site might reduce cancer aggressiveness in advanced disease. In advanced disease, however, reduction of angiogenesis would be the cause of tumor aggressiveness. These results suggest that statins might be used in prophylaxis or treatment of CRC. Further studies are needed to evaluate the effect of various types and doses of statins. Citation Format: Belal Al-Husein. Immunomodulatory effect of statins on Tregs within human colorectal cancer is determined by the stage of disease [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1713.