CLINICAL USEFULNESS OF COMPUTER-ASSISTED DIAGNOSIS USING COMBINATION ASSAY OF TUMOR-MARKERS FOR PANCREATIC-CARCINOMA

Background. There has been extensive use of serum tumor markers in dia gnosing pancreatic adenocarcinoma. There is no tumor marker, however, that alone has sufficient diagnostic accuracy. It is necessary to know which combination of tumor markers should be used to detect pancreati c cancer, with respect to clinical usefulness and cost effectiveness. Methods. Serum levels of 17 kinds of tumor markers were determined in 145 patients and 40 healthy volunteers. Thirty-five patients with prov en pancreatic adenocarcinoma, and 32 with benign pancreatobiliary dise ase (14 chronic pancreatitis and 18 biliary stones) were selected. For analysis of the usefulness of each tumor marker to differentiate thes e two groups, scatterplot and relative operating characteristic (ROC) analyses were used. A multivariate discriminant system to differentiat e these two groups was developed using stepwise discriminant analysis by backward elimination selection. Results. The significance of each t umor marker varied according to the tumor volume. By ROC analysis, the markers were divided into four subgroups according to their usefulnes s in discriminating pancreatic adenocarcinoma from benign pancreatobil iary disease. A discriminant system consisting of two different discri minant functions using nine tumor markers (CA 19-9, DUPAN-2, TPA, elas tase-1, lipase, amylase, gamma-glutamyl transpeptidase, alkaline phosp hatase, and lactate dehydrogenase) was developed and designated CAMPAS -P; it could differentiate between all 35 cases of pancreatic adenocar cinoma and 32 cases of benign pancreatobiliary disease. On the other h and, CAMPAS-P showed a low positive rate in pancreatic tumors of unusu al histologic type, and poor organ-specific diagnostic ability in vari ous digestive organ malignancies. Conclusions. CAMPAS-P may be very us eful for differential diagnosis between pancreatic adenocarcinoma and benign pancreatobiliary disease.