title: Alternative antibody for the detection of CA15-3 antigen: a European multicenter study for the evaluation of the analytical and clinical performance of the Access BR Monitor assay on the UniCel Dxl 800 Immunoassay System.
abstract: BACKGROUND
  Cancer antigen CA15-3 antigen is known as a valuable marker for the management of breast cancer.
  
  
  METHODS
  The analytical and clinical performance of the Access BR Monitor Immunoassay System (Beckman Coulter) was evaluated at five different European sites and compared with a reference system, defined as CA15-3 on the Elecsys System (Roche Diagnostics).
  
  
  RESULTS
  Total imprecision (% CV) of the BR Monitor ranged between 5.5% and 11.7%, and inter-laboratory reproducibility between 3.4% and 5.1%. Linearity upon dilution showed a mean recovery of 98.5% (SD + 9.1%). Endogenous interferents had no influence on BR Monitor levels (mean recoveries: hemoglobin 112%, bilirubin 111%, triglycerides 108%). There was no high-dose hook effect up to 13,540 kU/L. Clinical performance investigated in sera from individuals showed a general correlation between the Access BR Monitor and Elecsys CA15-3 (R = 0.797), with a slope of 1.383. CA15-3 serum levels, as measured by the BR Monitor, were low in healthy individuals (n = 267, median = 11.9 kU/L, 95th percentile = 23.5 kU/L), higher in individuals with various benign diseases (n = 549, medians = 11.3-15.6 kU/L, 95th percentiles = 21.6-54.6 kU/L) and even higher in individuals suffering from various cancers (n = 995, medians = 11.2-22.8 kU/L, 95th percentiles = 30.0-429.7 kU/L). Best diagnostic accuracy for cancer detection against the relevant benign control group by the BR Monitor was found for locoregional and metastatic breast cancer, as well as for ovarian cancer [area under the curve (AUC) 0.619, 0.897 and 0.774]. Results for the reference CA15-3 assay were comparable (AUC 0.611, 0.887 and 0.818).
  
  
  CONCLUSIONS
  The Access BR Monitor provides accurate methodological characteristics and demonstrates an analytical and clinical correlation with Elecsys CA15-3. Best diagnostic accuracy for the BR Monitor was found in breast and ovarian cancer. Our results also suggest a clinical value of the BR Monitor in other cancers.
authors.affiliation: Laboratory for Clinical Biochemistry and Molecular Genetics, Hospital Clinic, Barcelona, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Molina
authors.forename: Massimo
authors.initials: M
authors.lastname: Gion
authors.forename: Axel
authors.initials: A
authors.lastname: Gressner
authors.forename: Frédéric
authors.initials: F
authors.lastname: Troalen
authors.forename: Jose Maria
authors.initials: JM
authors.lastname: Auge
authors.forename: Stefan
authors.initials: S
authors.lastname: Holdenrieder
authors.forename: Matelda
authors.initials: M
authors.lastname: Zancan
authors.forename: Matthias
authors.initials: M
authors.lastname: Wycislo
authors.forename: Petra
authors.initials: P
authors.lastname: Stieber
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies / Q000737:chemistry*; D019540:Area Under Curve; D001943:Breast Neoplasms / Q000097:blood / Q000175:diagnosis*; D005060:Europe; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D008875:Middle Aged; D018396:Mucin-1 / Q000097:blood*; D010051:Ovarian Neoplasms / Q000097:blood / Q000175:diagnosis*; D012015:Reference Standards; D015203:Reproducibility of Results
chemical_list: D000906:Antibodies; D018396:Mucin-1