Comparison of a novel assay for breast cancer mucin to CA15-3 and carcinoembryonic antigen.
OBJECTIVE
To compare the sensitivity and specificity of an automated microparticle enzyme immunoassay (MEIA) for breast cancer mucin (IMx BCM; Abbott Laboratories, North Chicago, IL) to that of CA15-3 and carcinoembryonic antigen (CEA) for detecting and monitoring breast cancer.


METHODS
IMxBCM was compared to assays of CA15-3 and CEA in 630 serum specimens from healthy women, and from women with breast cancer, other malignancies, benign breast conditions, or other benign diseases.


RESULTS
Analysis of the log-transforms for the three markers in all specimens showed a high correlation of IMxBCM with CA15-3 (r = .78), but not with CEA (r = .25). Based on a receiver-operating-characteristics (ROC)-curve analysis for any given specificity, IMxBCM was found to be a more sensitive marker than either CA15-3 or CEA for distinguishing 105 women with advanced or metastatic breast cancer from 89 healthy women (P = .003 and P = .04, respectively), from 98 women with benign breast conditions (P = .02 and P = .002), or from 191 women with benign diseases (P = .03 and P less than .0001). At 95% specificity, the sensitivities of IMxBCM, CA15-3, and CEA for detecting advanced or metastatic breast cancer were 69%, 51%, and 30%, respectively. Serial serum samples (n = 177) were analyzed in 20 additional metastatic breast cancer patients with measurable disease. Serial IMxBCM levels corresponded with the clinical course of disease in 80%, CA15-3 in 65%, and CEA in 60% of the 20 patients.


CONCLUSIONS
Increased sensitivity of IMxBCM, despite a high correlation with CA15-3, suggests that IMxBCM and CA15-3 may recognize distinct epitopes on the same molecule. Although further research is indicated, IMxBCM may provide a promising marker in the clinical management of breast cancer patients.
Daly
L
L
Department of Medicine, Duke University Medical Center, Durham, NC 27710.
Ferguson
J
J
Cram
G P
GP
Hars
V
V
George
S L
SL
McCarty
K S
KS
Bast
R C
RC
D000328:Adult; D000951:Antigens, Neoplasm / Q000097:blood*; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000097:blood*; D001943:Breast Neoplasms / Q000097:blood* / Q000473:pathology; D002272:Carcinoembryonic Antigen / Q000097:blood*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008875:Middle Aged; D009077:Mucins / Q000097:blood*; D009362:Neoplasm Metastasis; D012372:ROC Curve; D012680:Sensitivity and Specificity
D000951:Antigens, Neoplasm; D015295:Antigens, Tumor-Associated, Carbohydrate; D002272:Carcinoembryonic Antigen; D009077:Mucins; C057387:mucinous carcinoma-associated antigen