A comparison between pregnancy-associated alpha 2-glycoprotein (alpha 2-PAG), carcino-embryonic antigen (CEA), CA-125, and CA-15-3 as tumor markers in breast cancer.

Pregnancy-associated alpha 2-glycoprotein (alpha 2-PAG) has been advocated as a good marker for various malignant diseases, in particular carcinoma of the breast. Re-evaluation of previously published results was required and in this study the correlation between alpha 2PAG and CEA, CA-125, and CA-15-3 was investigated and the monitoring efficiency determined in comparison to these above mentioned markers. Overall monitoring efficiency of alpha 2-PAG was in the same range as the corresponding parameters of CEA and CA-125; specificity was very high at the expense of sensitivity, resulting in a high positive predictive value. Monitoring of such patients by alpha 2-PAG as sole marker is not recommended.