Objective:The aim of this study was to investigate lipid disorders and lipid peroxidation associated with the malignant transformation of colorectal adenoma. Methods:Analyses were based on data from 100 subjects with histologically confirmed adenomas (cases) and 50 adenoma-free control subjects, all of whom had colonoscopy. The subjects were divided into two groups:those with no adenoma and those with adenoma. According to subsite of adenomas the subjects with adenoma were divided into group of distal adenoma and group of proximal adenoma. According to histology of adenomas the subjects with adenoma were divided into group of villiform adenoma and group of tubular + tubulo-villous adenoma. Among the groups, the serum levels of triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), and lipid peroxidation product malondialdehyde (MDA) were compared in all the patients.Results:Plasma total cholesterol and MDA level in group of adenomas were significantly higher than that in group of control subjects, but plasma HDL-C level was low in group of adenomas (P < 0.05). Plasma total cholesterol and MDA levels were positively related to distal and villiform adenomas (P < 0.05). Conclusion:The findings suggest that altered lipid metabolism may be differentially associated with colorectal adenomas.