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.