Editorial

The treatment of metastatic breast cancer with adjuvant systemic therapy When using adjuvant systemic therapy, we frequently for-get that we are treating real and often quite large metastatic deposits of breast cancer. Any single focus may contain almost 109 cells and still be clinically undetectable or micrometastatic. In contrast to our experience with animal tumor models, there is very little, if any, clinical evidence to suggest that adjuvant systemic therapy ever eradicates these micrometastases or totally prevents any event in the natural history of breast cancer. Rather, the effects of ad-juvant therapy in the patient with early breast cancer are quite like the effects of therapy in patients with metastatic breast cancer. The growth of tumor deposits at sites distant from the original breast primary may be slowed for some period of time, and if this tumor control lasts long enough