PLASMA AMINO-ACID LEVELS IN PATIENTS WITH GASTROINTESTINAL CANCER

The concentrations of 20 amino acids were measured in the venous plasma of 10 patients with gastric cancer, 10 patients with colorectal cancer, and 50 control subjects. All subjects had not lost body weight and had no loss of appetite. In comparison with the control subjects, both groups of cancer patients had decreased plasma concentrations of arginine (Arg), proline (Pro), and glutamine (Gln). While colorectal cancer patients had decreased plasma concentrations of threonine (Thr), aspartate (Asp), and serine (Ser), gastric cancer patients had a decreased plasma concentration of valine (Val). Increased plasma levels of phenylalanine (Phe) and ornithine (Orn) were observed in both the colorectal and gastric cancer patients. These findings indicate that abnormalities in amino acid metabolism exist in colorectal and gastric cancer patients, but the mechanisms and consequences of these abnormalities are not yet clear. These findings, however, might contribute to a future strategy for designing new specific amino acid formulations for the treatment of gastrointestinal cancer.