Serum levels of CA 15-3, mucinous-like cancer antigen, carcinoembryonic antigen, tissue polypeptide antigen and tissue polypeptide-specific antigen (TPS) have been determined in 99 patients with T2-4 N0-1 M0 breast cancer (BC) before and after primary (neoadjuvant) chemotherapy and after surgery. As a whole, no difference in marker levels was apparent according to tumor and patient characteristics, with the only exception of TPS values, which showed an inverse relationship with the histologic grade. Serum marker levels did not substantially change with respect to baseline either after chemotherapy, despite the high response rate obtained, or after surgery. These data indicate a limited contribution of the primary tumor to the serum marker levels and are consistent for the scarce usefulness of marker evaluation in BC patients with an early stage of disease. Interestingly, pretreatment elevated CA 15-3 levels were correlated with a higher recurrence rate, further supporting the prognostic significance of this tumor marker.