Biological markers for breast carcinoma.

During the last decade, there has been an intense search for biological markers for breast carcinoma. Many different types of materials have been found that may be elevated in the body fluids of patients with this disease. However, no markers specific for breast cancer have been discovered and those currently available lack the sensitivity and specificity for early detection of the disease or for determining when the tumor burden is low. Problems may also occur in the interpretation of marker data due to apparent biological variations in synthesis or secretion. Plasma carcinoembryonic antigen (CEA), elevated in 60%-70% of patients with metastases, has had the most extensive evaluation. For the latter patients with increased plasma CEA, the levels in general are proportional to tumor burden. Changes in level with therapy correlate with measurable clinical parameters of response or progression in the majority of these patients. Specific patterns of serial CEA measurements after mastectomy may be helpful for predicting those patients most likely to develop recurrent disease. More recent attention has focused on trials of combinations of markers and on tissue measurement. The search for a specific marker for breast cancer using monoclonal antibody techniques is a promising area of considerable research interest.