[The significance of determination of urinary trypsin inhibitor related antigen in patients with cancer of the digestive organs].

A highly sensitive enzyme immunoassay was developed for the determination of urinary trypsin inhibitor related antigen (UTIRA) in plasma, urine and cancer tissues, and we investigated its significance as a tumor marker in patients with cancer of the digestive organs. Variations in UTIRA in plasma and urine were not associated with the age of the volunteers, but in urine, high average was observed in male volunteers. UTIRA levels in the urine of the patients with esophageal, stomach and colorectal cancer increased as the stage progressed, except in the patients with liver cancer. And those levels in the urine significantly decreased after a curative operation, but did not decrease after a non-curative operation. UTIRA levels in stomach cancer tissues were significantly higher than those in adjacent healthy mucosa, but UTIRA levels were not high in tissues of esophageal, colorectal and primary liver cancers. Therefore, we speculate that the high levels of UTIRA in urine and plasma in patients with cancer of the digestive organs may not be caused by UTIRA released from cancer tissues. The determination of UTIRA may be significant in a broad sense as an index of the cancer stage or recurrence of cancer, particularly of the stomach.