CELLULAR FIBRONECTIN CONCENTRATION IN THE PLASMA OF PATIENTS WITH MALIGNANT AND BENIGN DISEASES - A COMPARISON WITH CA-19-9 AND CEA

EDAcFN enzyme immunoassay (EIA) is a new tumour marker assay measuring the extra domain A-containing isoform of cellular fibronectin (cFN), a component mainly found in extracellular matrices. The concentration cFN was measured in plasma and serum from 468 patients with malignant and benign diseases. The concentrations of cFN were higher in plasma t han in serum. Using receiver operating characteristic (ROC) curve anal ysis, determination from plasma was superior to serum at specificity l evels higher than 78% and was chosen for further analysis. The highest frequencies of elevated cFN values were seen in patients with hepato- pancreato-biliary malignancies (50-67%). In pancreatic and bile duct c ancers, cFN provided little further information to that obtained by CA 19-9. The greatest advantage over CA 19-9 and CEA was seen in patient s with local colorectal cancer and in hepatocellular carcinomas. Four out of nine patients with Dukes' stage B colorectal cancer had an elev ated cFn level, but only one had an abnormal CEA level. In hepatocellu lar carcinomas, cFN was also compared with alpha-fetoprotein. The sens itivity of cFN (72%) was superior to that of AFP (61%), and concomitan t use of cFN and AFP raised the sensitivity to 83%. The highest freque ncies of elevated values in patients with benign diseases were observe d in those with severe liver disease (32%) and biliary (17%) and pancr eatic (24%) diseases. A combination of cFN and CA 19-9 showed the high est overall sensitivity of 47%, compared with 31% for cFN and 33% for CA 19-9. The corresponding specificities were 76% for cFN +/- CA 19-9, 85% for cFN and 83% for CA 19-9. The accuracy of a combination of cFN and CA 19-9 or CEA (60% respectively) was higher than that of cFN (55 %), CA 19-9 (55%) or CEA (45%) alone. In conclusion, the results of th e new cFN test are encouraging and further studies on larger patient m aterials have been started.