Abstract: |
Breast cancer is the most common malignancy in American women and, with the exception of lung cancer, the most lethal. At present, breast cancer cannot be prevented, although treatment and cure are possible with early detection. Breast cancer screening is highly advocated, and a concerted effort has been made to produce a blood test for detecting the disease. It has not been possible to devise any breast cancer tumor marker with the required sensitivity and specificity for early detection. Nonetheless, several circulating tumor markers have been proposed as diagnostic tools in patients afflicted with the disease. Prominent are recently developed tests based on monoclonal antibody technology capable of detecting mucin type glycoproteins as circulating antigens in breast cancer patients. The most promising tests are CA15-3 and BR27.29, both approved for limited use by the FDA. The intended application is the use of these tests in the follow-up of previously diagnosed patients to detect early recurrence of the disease. Published studies indicate that CA15-3 and BR27.29 are extremely accurate in reflecting disease activity and suggest that changes in tumor marker levels may be the earliest indicators of disease recurrence. An appreciation of the limitations of these markers and their appropriate use in the context of other diagnostic criteria may significantly enhance the clinician's ability to provide more effective management of breast cancer. |