SAN ANTONIODocetaxel (Taxotere), doxorubicin(Drug information on doxorubicin) (Adriamycin), and cyclophosphamide(Drug information on cyclophosphamide) (TAC) improved overall survival by 30% and disease-free survival by 28% at 5 years, compared with the standard combination of flu-orouracil, doxorubicin, and cyclophosphamide (FAC) as adjuvant therapy for women with node-positive, early-stage breast cancer, John R. Mackey, MD, reported at the 26th Annual San Antonio Breast Cancer Symposium (abstract 43).
Dr. Mackey, of the Cross Cancer Institute, Edmonton, Alberta, Canada, reported the second planned interim analysis of the Breast Cancer International Research Group (BCIRG) 001 study with 55 months of follow-up.
This Aventis-sponsored study is a head-to-head comparison of docetaxel-based chemotherapy and fluorouracil(Drug information on fluorouracil)-based chemotherapy in 1,491 pre- and postmenopausal women with stage T1-3, N1, M0 breast cancer. Eligibility criteria included no prior systemic therapy or radiotherapy for breast cancer, age of 70 or younger, and definitive surgical treatment of mastectomy or breast-conserving surgery that included axillary lymph node dissection.
The primary study endpoint is disease-free survival. Secondary endpoints are overall survival, toxicity, quality of life, and evaluation of pathologic and molecular markers for predicting efficacy. Enrollment began in June 1997 and was completed in June 1999, including patients from 111 sites in 20 countries.
After surgery, patients were randomized to TAC (n = 745) or FAC (n = 746). Planned subgroup analyses include hormone-receptor status and nodal involvement (one to three vs four or more positive nodes). Most patients had at least 2-cm tumors, two thirds had one to three positive nodes, and 75% were hormone-receptor positive.
Tumor samples were collected from 95% of patients for analysis of hormone- receptor status, HER-2 amplification, and other characteristics. Quality of life analyses are being done, and Dr. Mackey said they will be presented this year.
The first planned interim analysis of this study, with a median follow-up of 33 months, was presented at the American Society of Clinical Oncology 2002 annual meeting (abstract 141) and showed significant improvement in disease-free survival in favor of TAC. The data reported by Dr. Mackey confirmed and extended these findings. This second interim analysis was done after 400 disease-free survival events. The final analysis will be after 590 events.