[Recent progress in tumor markers of the digestive system]

Recent progress in our tumor marker study of the digestive system was described. Of carcinoembryonic antigen (CEA), we developed a new assay system for detecting the CEA derived from gastrointestinal tumor tissues selectively, and succeeded to diagnose 72% of colorectal cancer patients including Dukes' A and B classifications. Of mucus antigens, intestinal IMA and gastric GMA, both were fractionated and purified in our laboratory, were demonstrated to be useful markers in detecting carcinofetal-type GI epithelia. Finally, a pancreas cancer-associated antigen (PCAA) derived from normal colonic mucosa in our laboratory, was shown to be identical immunochemically with Gelder's POA. Our results of the combined assay of PCAA and a pancreas tissue antigen (PaA) levels in sera from pancreatic cancer patients were evaluated to be positive in 90% of cases.