Comparison of fifteen immunoassays for the measurement of serum MUC-1/CA 15-3 in breast cancer patients.

Background: Quality control results for serum MUC-1/CA 15-3 assays have always shown large discrepancies.

Methods: This multicentre study of 15 methods (labelled M1-M15) measured coded sera from 35 patients with breast cancer without recurrence (group 1), 46 patients at 1st metastasis (group 2), and 39 patients with advanced metastases (group 3). Results were compared using parametric statistics, ANOVA, principal component analysis, and receiver operating characteristic (ROC) curves.