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.


RESULTS
Mean MUC-1/CA 15-3 concentrations varied widely (75.1-303.0 U/mL, 24.8%) among methods. The false positive (FP) rate for group 1 was 8/521 (1.5%); for group 2 and group 3 false negative (FN) results were 21/680 (3.1%) and 11/583 (1.9%), respectively. Using the ROC cut-offs, we found no FPs for group 1 and no FNs for group 3. However, group 2 showed 16 FNs. All p-values for Pearson's correlation were <0.0001 between methods, except for M11. When comparing methods using different antibodies, discordance rates reached a maximum of 15.2%. Principal component analysis revealed a grouping of methods using: CanAg monoclonal antibodies (mAbs) (M2, M7 and M12); Centocor/Fujirebio mAbs (M3-M6, M8-M10, M14-M15) and Biomira mAbs (M1 and M13); and Centocor/Fujirebio mAbs (M11).


CONCLUSIONS
Results were more consistent among methods using the same antibody type. Principal component analysis showed that antibody type was the strongest determinant of immunoassay results.
Pichon
Marie-France
MF
Laboratoire d'Oncobiologie, Centre René-Huguenin, Saint-Cloud, France. labonco@crh1.org
Brun
Gaëlle Le
GL
Hacene
Kamel
K
Basuyau
Jean-Pierre
JP
Riedinger
Jean-Marc
JM
Eche
Nicole
N
Fulla
Yvonne
Y
Charlier-Bret
Natacha
N
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000473:pathology; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008875:Middle Aged; D018396:Mucin-1 / Q000097:blood*; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D012008:Recurrence
D018396:Mucin-1