CEACAM5 and breast cancer: Similarly, in breast cancer, the diagnostic values of both CA 15 − 3 and CEA were limited (ROC AUC: 0.65; 95% CI: 0.55–0.75 and 0.61; 95% CI: 0.52–0.72, respectively), and the addition of hPG80 provided no improvement (CA 15 − 3 + hPG80: ROC AUC 0.67; 95% CI: 0.57–0.76; CEA + hPG80: ROC AUC 0.61; 95% CI: 0.52–0.72).