Comparison of immunoassays for tumor markers CA 19-9, CA 15-3 and CA 125: data from an international quality assessment scheme.
Data collected in the 1993 and 1994 cycles of an international external quality assessment (EQA) program and in a national multicenter collaborative study were cumulatively analyzed to evaluate the standardization of the methods currently in use for the assay of mucinous tumor markers CA 19-9, CA 15-3 and CA 125. On average the between-laboratory variability was 15.2 and 16.0 CV% for CA 15-3 and CA 125 respectively; the between-laboratory variability found for CA 19-9 was markedly worse (mean 28.3 CV%). The variability component attributable to systematic differences between different methods/kits was relatively small for CA 15-3 and CA 125 (18% and 24% of the total variability) but markedly larger for CA 19-9 (48% of the total variability). The agreement of CA 19-9 results worsened in the last few years when new nonisotopic techniques became available. The precision of the methods/kits most used in the survey ranged from 9.9 to 13.3 CV% for CA 125 and from 11.6 to 13.9 CV% for CA 15-3. For these two tumor markers the precision of the traditional IRMAs does not appear different from that of the new fully automated nonisotopic techniques. The precision of CA 19-9 methods was on average worse (from 11.7 to 19.6 CV%) although two automated systems exhibited a precision better than that of IRMAs. In conclusion, the results of this study indicate that CA 15-3 and CA 125 are satisfactorily assayed whereas CA 19-9 assay appears affected by larger differences between methods and by poorer precision of laboratories and kits.
Pilo
A
A
CNR, Istituto di Fisiologia Clinica, Pisa, Italy.
Zucchelli
G C
GC
Cohen
R
R
Bizollon
C A
CA
Cappelli
G
G
Cianetti
A
A
Gion
M
M
Piffanelli
A
A
Bombardieri
E
E
D015295:Antigens, Tumor-Associated, Carbohydrate / Q000097:blood*; D018394:CA-125 Antigen / Q000097:blood; D018395:CA-19-9 Antigen / Q000097:blood; D002272:Carcinoembryonic Antigen / Q000097:blood; D006801:Humans; D007118:Immunoassay / Q000379:methods / Q000592:standards; D015592:Immunoradiometric Assay; D007391:International Cooperation; D007558:Italy; D018396:Mucin-1 / Q000097:blood; D017430:Prostate-Specific Antigen / Q000097:blood; D011787:Quality of Health Care; D012044:Regression Analysis; D000509:alpha-Fetoproteins / Q000378:metabolism
D015295:Antigens, Tumor-Associated, Carbohydrate; D018394:CA-125 Antigen; D018395:CA-19-9 Antigen; D002272:Carcinoembryonic Antigen; D018396:Mucin-1; D000509:alpha-Fetoproteins; D017430:Prostate-Specific Antigen