A method for determining colorectal cancer risk includes obtaining a blood sample of the subject, isolating serum or EDTA plasma from the blood sample, analyzing the serum or EDTA plasma to determine plasma levels of very long chain dicarboxylic acid (VLCDCA 28:4), comparing the determined plasmas level of VLCDCA 28:4 of the subject with a predetermined range of plasma levels of VLCDCA 28:4 of diagnosed subjects having colorectal cancer, and determining a colorectal cancer risk exists when the determined plasma level of VLCDCA 28:4 is within the predetermined range of plasma levels of VLCDCA.