Ornithine decarboxylase: an unreliable marker for the identification of population groups at risk for colonic neoplasia.

Ornithine decarboxylase (ODC) is the first and rate-limiting enzyme in the polyamine biosynthetic pathway. Polyamines have been studied as potential markers of neoplastic diseases, including colonic cancer. Previous studies have pointed out the possible value of this enzyme as a biochemical marker of colonic neoplasia, we studied 100 patients undergoing diagnostic total colonoscopy. There were 40 normal controls and 20 patients in each of the following groups: 1) family members of patients diagnosed as having colonic tumors, 2) patients with adenomas, and 3) patients with colonic adenocarcinoma. Six forceps biopsies were obtained from the normal-appearing sigmoid mucosa for the analysis of ODC. No difference was found among the four groups studied. We therefore conclude that ODC is unreliable for clinical use as a biochemical marker for the identification of population groups at risk for colonic neoplasia.