The chemotherapy schedule that includes once-weekly administration of Taxol® (paclitaxel) in combination with Adriamycin® (doxorubicin) and Cytoxan® (cyclophosphamide) appears most effective in early breast cancer. These results were recently published in the New England Journal of Medicine.
Early breast cancer is cancer is confined to the breast and/or lymph nodes under the arm. Standard therapy for early breast cancer typically includes a combination of chemotherapy agents; often these chemotherapy agents include Adriamycin and Cytoxan (AC), followed by a taxane (Taxol or Taxotere® [docetaxel]). Until now, taxanes appeared to have similar anticancer activity to one another. Different treatment schedules including a taxane have been used, with the most common being once per week or once every three weeks.
Researchers affiliated with the Eastern Cooperative Oncology Group (ECOG), the Southwest Oncology Group (SWOG), the Cancer and Acute Leukemia Group G (CALGB), and the North Central Cancer Treatment Group (NCCTG) recently conducted a clinical trial that directly compared different taxanes as well as different treatment schedules. This trial included nearly 5,000 women with early breast cancer who were treated with standard AC followed by one of the following schedules including a taxane: Taxol every three weeks; Taxol once per week; Taxotere every three weeks; or Taxotere once per week. Follow-up was approximately five years.
- Cancer-free survival was 81.5% for Taxol once per week, 81.2% for Taxotere every three weeks, 77.6% for Taxotere once per week, and 76.9% for Taxol every three weeks.
- Overall survival was 89.7% for Taxol once per week, 87.3% for Taxotere every three weeks, 86.5% for Taxol every three weeks, and 86.2% for Taxotere once per week.
- Severe (grades III and IV) side effects occurred in 71% of patients treated with Taxotere every three weeks, 45% of patients treated with Taxotere once per week, 30% of patients treated with Taxol every three weeks, and 28% among those treated with Taxol once per week.
The researchers concluded: “Weekly [Taxol] after standard adjuvant chemotherapywith doxorubicin and cyclophosphamide improves disease-freeand overall survival in women with breast cancer.”
Patients with early breast cancer may wish to discuss their individual risks and benefits of all treatment options with their physician.
Reference: Sparano JA, Wang M, Martino S, et al. Weekly paclitaxel in the adjuvant treatment of breast cancer. New England Journal of Medicine. 2008;1663-1671.