Novel serum tumor marker, RCAS1, in pancreatic diseases.

AIM: As tumor markers for pancreatic carcinoma, carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 have been used, but the sensitivity and specificity are not enough for the diagnosis of pancreatic carcinoma. METHODS: A novel serum tumor marker, RCAS1, was compared with two conventional serum tumor markers, CEA (highly specific for pancreatic cancer) and CA 19-9 (highly sensitive for pancreatic cancer), in 48 patients with pancreatic exocrine tumors. RESULTS: When the diagnosis of benign or malignant conditions was examined by one tumor marker, the sensitivity of RCAS1 alone (55%) was higher than that of CEA alone (27%) and the specificity of RCAS1 alone (92%) was greater than that of CA19-9 alone (78%). When examined by a combination of two markers, the sensitivity of a combination of RCAS1 and CA19-9 (95%) was superior to those of CA19-9 alone (78%), RCAS1 alone (55%, P = 0.002), CEA alone (27%) (P<0.001), RCAS1 and CEA (59%) and CA19-9 and CEA (82%). CONCLUSION: These results suggest that the combination of RCAS1 and CA19-9 is highly sensitive for pancreatic carcinoma.