Adjuvant therapy for early stage breast cancer

Metastatic disease in women who have undergone appropriate local therapy remains the leading ultimate cause of death in breast cancer. Therapy for overt metastatic disease is unlikely to offer curative potential for any but a small proportion of patients. Therapy for micrometastatic disease is offered in the hope that patients with a smaller tumor burden will be more amenable to cure. This report will examine the extent to which this hope has been fulfilled and discuss the future of adjuvant therapy. The initial adjuvant therapy trials used chemotherapy to treat women with lymph node-positive breast cancer. These trials clearly demonstrated a disease-free and overall survival benefit for women receiving combination chemotherapy in the adjuvant setting. These benefits were subsequently extended to women with lymph node-negative disease, and (in the form of adjuvant hormonal therapy) to women with steroid receptor-positive breast cancer. Current adjuvant therapy clearly improves disease-free and overall survival in patients with micrometastatic disease. It is less clear whether these improvements translate to a "cure" in the sense of total elimination of micrometastatic disease. Numerous questions remain to be answered regarding the dose intensity of chemotherapy, the appropriate sequencing of chemotherapy agents, and the use of novel chemotherapy agents, such as the taxanes. These and other questions are the subject of ongoing clinical trials.