Compared to the standard chemotherapy combination of Adriamycin® (doxorubicin) and Cytoxan® (cyclophosphamide), adjuvant therapy with Taxotere® (docetaxel) and Cytoxan improves breast cancer outcomes and may be less toxic to the heart. These results were presented at the 28th annual San Antonio Breast Cancer Symposium.
The combination of Adriamycin and Cytoxan (AC) has long been considered a standard adjuvant chemotherapy regimen for the treatment of breast cancer. It’s been noted, however, that Adriamycin can cause heart complications, particularly in the elderly or patients with underlying heart problems. Furthermore, studies of women with advanced breast cancer have suggested that Taxotere has greater anticancer activity than Adriamycin. These observations prompted researchers to conduct a clinical trial to directly compare AC to Taxotere and Cytoxan (TC) as adjuvant therapy for breast cancer.
The study enrolled 1016 women with stage I, stage II, or operable stage III breast cancer. All had complete surgical removal of their cancer. Nearly half of the patients (48%) were lymph node-negative, 41% had 1-3 positive lymph nodes, and 11% had four or more positive lymph nodes.
Women were randomly assigned to receive either AC or TC every three weeks. Patients who were candidates for radiation therapy or tamoxifen received these treatments after chemotherapy.
After five years of follow-up, patients treated with TC had better outcomes than patients treated with AC:
- 86% of patients treated with TC were alive and cancer-free, compared to 80% of patients treated with AC.
- There was no significant difference in overall survival. (An improvement in overall survival may become apparent with additional follow-up.)
- TC was generally better tolerated than AC; neutropenia was more common in patients treated with TC; nausea and vomiting were more common in patients treated with AC.
Information about heart complications was not presented, but it was noted that TC appears to pose less risk to the heart than AC.
The researchers concluded that adjuvant therapy with TC results in better cancer-free survival than adjuvant therapy with AC and that TC may become a standard adjuvant treatment option for breast cancer.
Reference: Jones S, Savin M, Holmes F, et al. Final analysis: TC (docetaxel/cyclophosphamide, 4 cycles) has a superior disease-free survival compared to standard AC (doxorubicin/cyclophosphamide) in 1016 women with early breast cancer. Proceedings from the 28th San Antonio Breast Cancer Symposium. December 2005. Abstract #40.