COMPARISON OF 7 IMMUNOASSAYS FOR THE QUANTIFICATION OF CA-125 ANTIGENIN SERUM

Seven CA 125 immunoassays were compared for their clinical performance . CA 125 concentrations were determined in 289 serum samples obtained from women with benign pelvic tumors (samples from 98 patients) and pa tients with various cancers (samples from 111 patients). In the range of 0-1000 kilounits/L, all assays tested were linearly correlated, wit h correlation coefficients ranging from 0.89 to 0.99. In relation to t he original Centocor CA 125 assay, there was an overall tendency to me asure higher absolute values in the lower CA 125 value range. This was not seen in relation to the Centocor CA 125 II assay. ROC curves (ben ign vs pretreatment ovarian cancer patients) were nearly identical for all assays, and the areas under the ROC curves were not markedly diff erent. We conclude that the CA 125 assays tested are strongly related to each other and are clinically reliable for the quantification of se rum CA 125 and that none of the assays offers higher diagnostic accura cy or better discrimination between patient groups, especially not in the lower ranges.