OBJECTIVETo evaluate the effect of receptor-binding cancer antigen expressed on SiSO cells (RCAS1) as serum tumor marker on the diagnosis of pancreatic cancer.

METHODSReceiver-operating characteristics (ROC) curve methods were used to assay the serum content of RCAS1, CA19-9 and CA242 in 46 patients with pancreatic cancer, 18 patients and 20 normal tissues of chronic pancreatitis detected by enzyme linked immunosorbent assay (ELISA), and the results were analyzed by statistics methods. The expressions of RCAS1 protein were analyzed by immunohistochemical method in 32 patients with pancreatic cancer, 10 patients with chronic pancreatitis and 6 cases of normal pancreatic specimens.

RESULTSThe serum levels of RCAS1, CA19-9 and CA242 in pancreatic cancer were higher than that in chronic pancreatitis respectively (P < 0.01). The area under curve of RCAS1, CA19-9 and CA242 were 0.826, 0.804 and 0.737, respectively. Subgroup analysis indicated that the RCAS1 and CA19-9 levels of pancreatic cancer patients without obstructive jaundice were lower than those for patients with obstructive jaundice (P < 0.01). CA19-9 levels of patients with resectable pancreatic cancer were lower than those with unresectable pancreatic cancer (P < 0.01). Immunohistochemistry showed that the expression rates of RCAS1 in pancreatic cancer and chronic pancreatitis were 87.5% and 40.0%, respectively (P < 0.05).

CONCLUSIONSIn diagnosis of pancreatic cancer, the clinical value of RCAS1 is available. And the combination test of RCAS1 and CA19-9 have clinical value to evaluate if the pancreatic cancer can be resected before operation.