Immunoassay of CA125 in ovarian cancer: a comparison of three assays for use in diagnosis and monitoring.

There is increasing evidence to support the use of CA125 in the follow-up and management of patients with ovarian cancer and several commercial kits are now available for its measurement. This study investigated and compared the performance of three of them: an enzyme immunoassay (EIA) and an immunoradiometric assay (IRMA) from Abbott Diagnostics, and an IRMA from CIS, U.K. One hundred and thirty-two serum samples from 42 patients with advanced epithelial ovarian cancer were thawed once and assayed for CA125 using each kit. Both IRMAs performed better than the EIA in terms of CV, sensitivity, specificity, and accuracy. The results confirm the usefulness of CA125 as a marker for ovarian cancer. However, discrepancies between results using different kits suggest the need for improved standardization.