[Diagnostic values of type III Procollagen N-terminal peptide and combination assay of type III procollagen N-terminal peptide with CEA and CA 19-9 in gastric cancer].

It is known that interstitial collagens are initially synthesized as precursors (procollagen), which possess extra peptide segments at both ends of the molecules. The authors attempted to detect the aminoterminal peptide of type III procollagen (type III-N-peptide) and also to measure the carcinoembryonic antigen (CEA) and carbohydrate antigen (CA 19-9) together in sera of patients with gastric cancer. The results showed that: (1) mean serum levels and positive ratios of the type III-N-peptide increased as the clinical stage of the patients with gastric cancer advanced; (2) serum levels of the type III-N-peptide were not correlated either with those of CEA or CA 19-9; (3) positive ratios of type III-N-peptide, CEA and CA 19-9 were 51.7%, 44.8% and 48.3%, respectively: (4) positive ratio in combination of the type III-N-peptide with CEA was 69.3% and that in combination of the type III-N-peptide with CEA and CA 19-9 was 72.4%. These results suggest that type III-N-peptide is available for diagnosis of gastric cancer and, that the combination assay of type III-N-peptide with CEA and CA 19-9 is more effective than a single assay for diagnosis.