Tumor markers were studied in the sera of 883 untreated patients with primary breast cancer diagnosed between 1989 and 2007. Abnormal human epidermal growth factor receptor 2 (HER-2)/neu levels (>15 ng/mL) were found in 9.5%, carcinoembryonic antigen (CEA) in 15.9%, and cancer antigen (CA) 15.3 in 19.7% of the patients. One or more tumor markers were abnormal in 305 (34.5%) of the 883 studied patients. Significantly higher serum HER-2/neu levels were found in patients with tissue overexpression of this oncoprotein (p<0.0001). CEA, CA 15.3, and HER-2/neu (only in those patients with tissue overexpression) serum levels were related with tumor stage (tumor size and nodal involvement) and steroid receptors (higher values in estrogen receptor-negative (ER−) tumors). Univariate analysis showed that HER-2/neu serum levels were prognostic factors in disease-free survival (DFS) and overall survival (OS) only in patients with tissue overexpression. Multivariate analysis in 834 patients show that nodal involvement, tumor size, ER, CEA, and adjuvant treatment were independent prognostic factors in DFS and OS. When only patients with HER-2/neu overexpression in tissue were studied, tumor size, nodal involvement, and tumor markers (one or another positive) were independent prognostic factors for both DFS and OS. HER-2/neu serum levels were also an independent prognostic factor, with CEA, ER, and nodes in 106 patients treated with neoadjuvant treatment. In summary, serum HER-2/neu, CEA, and CA 15.3 are useful tools in the prognostic evaluation of patients with primary breast cancer.
Recommendations are presented for the routine clinical use of serum and tissue-based markers in the diagnosis and management of patients with breast cancer. Their low sensitivity and specifi city preclude the use of serum markers such as the MUC-1 mucin glycoproteins (CA 15.3, BR 27.29) and carcinoembryonic antigen in the diagnosis of early breast cancer. However, serial measurement of these markers can result in the early detection of recurrent disease as well as indicate the effi cacy of therapy. Of the tissue-based markers, measurement of estrogen and progesterone receptors is mandatory in the selection of patients for treatment with hormone therapy, while HER-2 is essential in selecting patients with advanced breast cancer for treatment with Herceptin (trastuzumab). Urokinase plasminogen activator and plasminogen activator inhibitor 1 are recently validated prognostic markers for lymph node-negative breast cancer patients and thus may be of value in selecting node-negative patients that do not require adjuvant chemotherapy.