Comparison of a novel assay for breast cancer mucin to CA15-3 and carcinoembryonic antigen.

PURPOSE: 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. MATERIALS AND 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.

Expression and amplification of the HER-2/neu (c-erbB-2) protooncogene in epithelial ovarian tumors and cell lines.

Amplification of the c-erbB-2 protooncogene has been associated with a poor prognosis in human breast and ovarian cancers. Our study was undertaken to examine whether amplification, rearrangement, or overexpression of c-erbB-2 and other protooncogenes was frequently observed in epithelial ovarian cancers. c-erbB-2 was expressed in 87% of 22 ovarian cancers analyzed, but expression was significantly increased in only one of the 22 tumor specimens. In this case elevated c-erbB-2 expression was associated with dramatic amplification of the gene. In another tumor a 3.8 kb EcoRI fragment was found, in addition to the usual 4.4 and 6.0 kb fragments; this is consistent with a possible gene rearrangement or a restriction fragment length polymorphism. To place these results in perspective, expression of several other protooncogenes has been examined in ovarian carcinomas. The c-fos, c-myc, n-myc, c-fms, and c-Ha-ras protooncogenes were expressed in different fractions of tumors, but expression of l-myc, c-erbB, c-myb, c-sis, and c-mos was not detectable. Aside from c-erbB-2, neither amplification nor rearrangement was observed among the other protooncogenes studied. Expression of c-erbB-2, c-fms, c-myc, n-myc, c-fos, and c-Ha-ras deserves further evaluation as a prognostic factor in ovarian cancer.