Combining the tumor abnormal protein test with tests for carcinoembryonic antigens, cancer antigen 15-3, and/or cancer antigen 125 significantly increased their diagnostic sensitivity for breast cancer.

Background: The tumor abnormal protein (TAP) test is used to screen for many cancers, but its use for breast cancer has not been studied. Methods: Tests for carcinoembryonic antigen (CEA), cancer antigen 125 (CA125), cancer antigen 15-3 (CA15-3), and TAP were administered to 261 women with operable benign breast disease and 348 with breast cancer. The cutoff value used for TAP was the mean + 3 standard deviations for benign breast disease patients (275.64 mu m(2)). Sensitivities and specificities of single biomarker tests and combined tests were compared. The combined tests were defined as positive if any single biomarker was positive, and negative otherwise. Results: The single biomarker test sensitivities were similar: CEA, 7.18%; CA125, 4.89%; CA15-3, 7.47%; and TAP, 4.89%. For the combinations TAP + CEA + CA125, TAP + CEA + CA15-3, TAP + CA125 + CA15-3, and TAP + CEA + CA125 + CA15-3, the sensitivities were 16.67%, 17.82%, 16.38%, and 21.84%, respectively, and the specificities were 93.49%, 97.70%, 93.87%, and 92.72%. Conclusions: The 4-test combination showed the highest sensitivity (21.84%) and may be auxiliary used in early screening. TAP + CEA + CA15-3 showed high specificity (97.70%) and so could be used for confirming breast cancer.