Beyerle J, Holowatyj AN, Haffa M, et al. - In order to clarify the role of xenobiotic-metabolizing enzymes (XMEs) in colorectal carcinogenesis, researchers analyzed patients having stage I–IV colorectal cancer (n = 71) from the ColoCare Study. They examined the expression of XMEs in human colorectal tissues among these patients. Normal tissues in women exhibited significantly higher expression of GSTM1 vs men. By tumor site, lower expression of CYP2C9 was noted in normal mucosa in patients suffering from rectal cancer vs colon cancer cases. Normal mucosa in smokers vs nonsmokers exhibited higher CYP2C9 expression levels. Higher GSTP1 tumor expression was detected in people who used NSAIDs vs non-NSAID users. Higher CYP3A4 expression in colorectal tumor tissues was observed in relation to a higher intake of cooked vegetables (> 1×/week). Findings revealed lower expression of XMEs in colorectal tumor compared with normal mucosa tissues, as well as the possible ability of XMEs in altering colorectal carcinogenesis through links with clinicopathologic, lifestyle, and dietary factors.