Chemoprevention of colorectal cancer by mesalamine/sulfasalazine

A method for preventing colorectal cancer in a patient possessing human tropomyocin isoform TC22 is disclosed. The method comprises: (a) detecting a serum protein concentration of TC22 in a patient and (b) administering to said patient prior to detecting colorectal cancer in said patient a therapeutically effective amount of a chemotherapeutic composition comprising a chemotherapeutic compound that reduces the level of TC22, wherein the chemotherapeutic compound is selected from the group consisting of sulfasalazine, 5-amino-2-hydroxybenzoic acid, osalazine, and balsalazide.