EVALUATION OF THE IMMULITE(R) BR-MA AND CEA ASSAYS AND COMPARISON WITH IMMUNORADIOMETRIC ASSAYS FOR CA15-3 AND CEA IN BREAST-CANCER

This study was designed to evaluate the performance of a new automated assay system, the IMMULITE (R) Automated Immunoassay Analyzer in comp arison with more commonly used IRMA assays for measuring circulating t umour marker levels in breast cancer-patients. The assays investigated measure the MUC1 mucin (CA15-3 antigen) or CEA. Serum samples from br east cancer patients with various stages of disease and from a group o f normal individuals were analysed. Significant correlations were foun d between tumour marker levels measured using the IMMULITE (R) BR-MA a nd the CA15-3 assays and between levels measured using the two CEA ass ay formats. Levels of IMMULITE (R) BR-MA and CEA correlated with stage of disease suggesting that both are markers of tumour burden Levels i n Stage III breast cancer patients were found to be significantly high er than those of normals using the IMMULITE (R) system but not the IRM A assays. This would suggest a role for the automated system in the mo nitoring of breast cancer at an earlier stage than that at which tumou r markers are routinely used. Elevated marker levels did not correspon d to any particular site of metastasis however a greater proportion of patients with multiple sites of metastasis had elevated levels compar ed with those with secondary disease at a single site. We conclude tha t the IMMULITE (R) Automated Immunoassay Analyzer is of value in the r outine surveillance of tumour marker levels.