NuMA: evaluation of a new biomarker for the detection of low stage colorectal cancer

An enzyme immunoassay for NuMA was evaluated in a retrospective clinical study for its potential utility in the detection of colorectal cancer. The concentrations of NuMA and CEA (Abbott IMx) were measured in sera from 86 patients (presurgical) with colorectal cancer, 72 subjects with benign gastrointestinal diseases, 80 subjects with risk factors for colorectal cancer, and 141 age-matched healthy subjects. Reference values for NuMA and CEA were calculated by two methods: 95% cumulative distribution and ROC analyses versus healthy subjects. By the first method, NuMA and CEA both had approximately 20% sensitivity for colorectal cancer. By the second method (which generated lower reference values), NuMA was more sensitive than CEA for colorectal cancer. This improved sensitivity was most evident in Dukes B subjects. By either analysis method, NuMA was more sensitive than CEA for subjects at risk for developing colorectal cancer, whereas CEA was more specific for benign gastrointestinal diseases.

An enzyme immunoassay for carcinoembryonic antigen which employs simultaneous incubation of specimen with solid phase and enzyme-conjugated antibodies

The Abbott CEA-EIA Monoclonal One-Step procedure was evaluated and compared to the Abbott CEA-EIA Monoclonal, a two-step assay. The reproducibility, sensitivity, recovery and dilution linearity were similar for both assays. Excellent correlations were found between the carcinoembryonic antigen (CEA) values obtained with these assays for healthy donors (n = 261, r = 0.951), patients with benign diseases (n = 171, r = 0.994) and cancer patients (n = 585, r = 0.997). In serial monitoring studies, one-step CEA values paralleled the CEA values determined with the two-step assay regardless of the type of cancer. The advantages of the one-step CEA assay over the two-step assay include significant reduction in both attended and total assay times, reduced sample volume, dry antibody-coated beads, color-coded reagents and an extended range for the standard curve. These test improvements were achieved without affecting the reproducibility, sensitivity and accuracy of the CEA measurement.