Current status of adjuvant therapy of early breast cancer.

Adjuvant therapy in operable breast cancer (stage I and II) can significantly reduce the risk of recurrences and improve survival. In stage I disease, 20-30% of patients will eventually recur. Several prognostic factors may help in identifying poor prognostic subgroups of stage I patients, including ER and PR status, flow cytometry data, nuclear grade, neu oncogene expression, and perhaps haptoglobin-related protein, Cathepsin-D, and Ki-67 expression. Single-agent chemotherapy and oophorectomy have not resulted in prolongation of survival. Combination chemotherapy regimens are superior to single agents, and doxorubicin-containing regimens may be superior to non-doxorubicin-containing regimens. Tamoxifen is effective in improving survival in patients who are ER positive, particularly those women older than 50 years. It appears that six cycles of an effective regimen is as effective as more prolonged administration of the same drugs, and drugs should be given at the optimal dose rate. Preliminary results of alternating non-cross-resistant chemotherapy regimens show promise, but additional data are needed to determine its impact on survival.