[Diagnostic value of serum CA 19-9 determination in digestive tract cancer].

Serum carbohydrate antigen CA 19-9 level was measured by radioimmunoassay in 55 patients with malignant digestive disease (14 esophageal cancers, 11 gastric cancers, 5 colorectal cancers, 14 primary liver cancers and 11 pancreatic cancers). The mean value of serum CA 19-9 levels was 22.11 +/- 24.79 u/ml in esophageal cancer, 99.91 +/- 100.12 u/ml in gastric cancer, 64.5 +/- 53.43 u/ml in colorectal carcinoma, 47.81 +/- 68.62 u/ml in primary hepatic cancer and 459.55 +/- 696.76 u/ml in pancreatic cancer (CA 19-9 greater than 37 mu/ml as positive). There were significant differences (P less than 0.05) between the mean serum CA 19-9 levels of pancreatic cancer and esophageal cancer, primary hepatic cancer. An increased CA 19-9 synthesis and excretion by tumor cells or increased pressure on pancreatic duct by the tumor may cause the elevation of serum CA 19-9 level in cancer patients. The authors conclude that CA19-9 is a valuable tumor marker in the diagnosis of pancreatic cancer and, probably, other gastrointestinal tumors.