Simultaneous multianalyte immunoassay measurement of five serum tumor markers in the detection of colorectal cancer.

Several serum tumor markers (STMs) have been proposed for the diagnosis of colorectal cancer (CRC), but their detection should be combined to increase accuracy. The measurement of a serum biomarker panel may improve the diagnostic value of single STM and a multianalyte immunoassay approach can shorten assay time and lower sample consumption. The aim of this study was to determine whether the simultaneous multianalyte immunoassay is useful for early detection of CRC. We measured a panel of five STMs namely, carcinoembryonic antigen (CEA), cancer antigen (CA) 19-9 and 72-4, cytokeratin fragment (CYFRA) 21-1, and osteopontin, in a selected homogeneous population of 102 consecutive patients (median age 66 years, range 42-75 years) with Dukes B, G1-2, colorectal adenocarcinoma (cases) and in a group of 99 age- and sex-matched patients suffering from confirmed benign colorectal diseases (controls). Overall, 141 (70.1%) men and 60 (29.9%) women were studied. The highest sensitivity was 45.1% (osteopontin), while the highest specificity was 90.9% (CEA). The accuracy was lower, ranging from 24.9% (CA 19-9) to 67.2% (CEA). CYFRA 21-1 and CA 72-4 had similar sensitivity (35.3% and 31.4%, respectively), but a significantly different specificity (37.4% vs. 89.9%). A combination of the five markers achieved 74.1% sensitivity and 94.3% specificity. In conclusion, in patients with CRC all single STMs show low sensitivity and specificity, while the simultaneous measurement of a panel of STMs may increase the diagnostic accuracy. When the sample volume is limited, the multianalyte immunoassay can be a reliable tool for studying patients undergoing laboratory screening for CRC.