Roche RIA and Abbott EIA carcinoembryonic antigen assays compared.

Abstract

We have evaluated Roche Diagnostics' RIA-CEA and Abbott Diagnostics' EIA-CEA methods for precision, normal reference interval, concordance, and correlation of malignant disease with increase in carcinoembryonic antigen (CEA) in plasma. In examining concordance, we used data on 138 patients with primary carcinomas of the breast, colon, lung, or pancreas, each further classified by extent of dissemination. We find the two methods to be comparably precise. The respective upper reference limits of normal for the Roche and Abbott methods were determined to be 5.0 micrograms/L and 4.6 micrograms/L. The regression equation for a log transformation of the 177 data points is y = 0.966x + 0.03, where x = Roche and y = Abbott, with a correlation coefficient of 0.948. According to the criteria we used, the concordance was 78.7%. The largest discordance was observed in widely disseminated disease states and in cancers of the colon and pancreas. Paired data analysis of discordance indicated greater increases in apparent CEA by the Abbott method in most colon cancers with liver involvement; six of the eight discordant pancreatic cancers had higher Roche-CEA values. CEA heterogeneity and the role of the liver in CEA metabolism appear to contribute to the observed differences. We show why the two methods should not be used interchangeably, and that baseline values for CEA must be established for each method.

The influence of metastatic site on the expression of CEA and cellular localization of β‐catenin in colorectal cancer

“…CEA levels in patients with early stages of CRC are barely above an empirical cut‐off value of the healthy subjects. For instance, by using a cut‐off point of 2.5 ng/mL, the proportion of patients with increased serum CEACAM5 levels was 28% for Dukes’ A tumors, and at a cut‐off point of 5 ng/mL, this value was 3% . These studies suggest that an increase in serum CEA level above 2.5 ng/mL is of diagnostic value for identifying premalignant CRC disease.…”

Specific expression of the pancreatic‐secretory‐trypsin‐inhibitor (PSTI) gene in hepatocellular carcinoma

“…In view of our previous finding that the mean f SD of serum PSTI level in 199 healthy volunteers was 10.11 f 2.15 ng/ml, we set the cut-off level at 17 nglml, considering that the normal range was mean + 2SD and that the serum-PSTI level increases upon aging. The cut-off levels for AFP, CEA and CA19-9 were set at 10 ng/ml, 5 ng/ml and 37 U/ml respectively, as adopted from previous studies (Fleisher et al, 1984;Del Villano et aL, 1983). Among the 27 patients with HCC, 44% were PSTI-seropositive.…”

Immunoliposome-PCR: a generic ultrasensitive quantitative antigen detection system

“…The LOD was 10 -16 M, which corresponds to 13 fg/ml of CEA or 6,023 molecules (10 zeptomoles) of CEA in a 100-μL serum sample. This LOD was >1,500 times lower than the best clinically-approved ELISA or RIA tests for CEA [ 39 - 41 ], while IPCR assays for CEA in serum [ 42 , 43 ] reported an LOD ≥ 900,000 molecules and a dynamic range of 10 3 . The ILPCR assay results were independent of serum dilution, demonstrating the insensitivity of the assay to matrix effects.…”