COMPARATIVE-STUDY OF CA242 AND CA19-9 IN CHRONIC-PANCREATITIS

CA242 has been proved to be useful in the diagnosis of pancreatic canc er, The aim of the present study was to clarify the mechanisms contrib uting to the high specificity of CA242 as compared with CA19-9 resulti ng from scarce serum elevation of this antigen in patients with chroni c pancreatitis by correlating serum levels and endoscopic retrograde c holedocho-pancreatography (ERCP) findings and by immunohistochemical a nalysis. Serum CA19-9 levels were significantly elevated in patients w ith calcification and with main pancreatic duct (MPD) stenosis or obst ruction. On the other hand, serum CA242 levels showed no significant e levation in patients with such factors. Even though such pathological conditions were considered to lead to the stagnation of pancreatic jui ce, serum CA242 levels seemed to be less affected than serum CA19-9 le vels. Immunohistochemical studies of chronic pancreatitis tissues reve aled that CA242 was expressed less Frequently and less intensely than CA19-9, and the difference in expression was more prominent in the cen troacinar cells and terminal ductules. From the results of the present study, it is conceivable that CA242 is less influenced by the stagnat ion of the pancreatic juice than CA19-9 because of the low levels of e xpression in ductal systems, which results in the release of this anti gen into the circulation in lower amounts than that of CA19-9.