High serum folate might have a potential dual effect on risk of colorectal cancer

Summary Background & aims The possible dual role of serum folate in the development and progression of colorectal cancer (CRC) has not been well established in human studies. This study investigated the association between serum folate and the risk of CRC in subjects with CRC or colorectal adenomatous polyps (AP, a precursor of CRC), and healthy subjects. Methods This study has a case–control design. Two hundred and thirty-seven men and 171 women were recruited with 156 subjects in the CRC group, 70 subjects in the AP group and 182 healthy subjects in the control group. Results The risk of CRC was significantly increased in the third (OR, 3.46; 95% CI, 1.16–10.34) and fourth (OR, 4.86; 95% CI, 1.42–16.58) quartiles of serum folate concentration after adjusting for potential confounders among subjects with AP or CRC. Furthermore, serum folate concentration had no significant effect on the risk of CRC among subjects in the control and CRC groups. Conclusions Higher serum folate concentration was significantly correlated with increased CRC risk in subjects with AP, while serum folate had no effect on CRC risk in healthy controls. Serum folate might possess potential dual modulatory effects on the risk of CRC.