Systemic adjuvant therapy of breast cancer

Following local excision, the prognosis for long-term cure of a patient with breast malignancy depends on the presence of micro-metastatic disease. The risk of occult disease present prior to removal of the primary tumor can be assessed by knowledge of the tumor size, histology and degree of differentiation, and spread to axillary nodes. It ranges from 25% in node-negative tumors to as much as 75% to 80% in the presence of multiple involved nodes. Systemic therapy can reduce the risk by approximately one-third. Present studies indicate that regardless of age or menopausal status the majority of women should be considered for chemotherapy (if hormone receptor negative) or chemotherapy and tamoxifen (receptor positive). However, it is hoped that further refinement of our knowledge of prognostic factors will allow better design of adjuvant therapy through better understanding of the mechanisms of tumor growth and spread.