Optimizing Adjuvant Chemotherapy in Early-Stage Breast Cancer
December 01, 2005
Mortality in breast cancer has declined in the past decade, owing toadvances in diagnosis, surgery, radiotherapy, and systemic treatments.Adjuvant chemotherapy has had a major effect on increasing survivalin women with locoregional breast cancer. Like all treatments, adjuvantchemotherapy is a work in progress, and it has evolved from singleoral agents to complex multidrug regimens. The choice of regimens isnot without controversy, however, and several have been shown to bemore effective than others, especially in patients who are at high riskfor recurrence. The taxanes paclitaxel and docetaxel (Taxotere) havebeen shown to be effective in the adjuvant setting, and they have alsobeen shown to improve the outcomes in node-positive disease. Bothdisease-free and overall survival are greater with doxorubicin,paclitaxel, and cyclophosphamide given in a dose-dense, every-2-weekschedule with growth factor support than with the same agents givenin an every-3-week schedule. Disease-free and overall survival in patientswith node-positive disease are greater with docetaxel, doxorubicin(Adriamycin), and cyclophosphamide (TAC) than with fluorouracil,doxorubicin, and cyclophosphamide (FAC). Febrile neutropenia iscommon with the TAC regimen, but it can be minimized with growthfactor support. Based on these findings, dose-dense therapy and TAC arethe current adjuvant treatments of choice in patients with node-positivedisease; other, less-intense regimens may be appropriate in patientswith lower-risk disease. Ongoing trials are investigating the efficacy ofcommonly used regimens, new chemotherapeutic and biologic agents,and novel doses and schedules of currently available agents.