Randomized Phase II Study of Adriamycin/Cytoxan/Taxol (ACT) vs. Cytoxan, Thiotepa, Carboplatin (STAMP V) in Patients With High-Risk Primary Breast Cancer

OBJECTIVES: Compare the toxic effects of doxorubicin, cyclophosphamide, and paclitaxel vs cyclophosphamide, thiotepa, and carboplatin in patients with high-risk primary breast cancer. (Arm I closed to accural as of 4/6/2006.) Compare the efficacies of these regimens followed by peripheral blood stem cell rescue in these patients. Determine the efficacy of a bisphosphonate to prevent relapse/metastasis after high-dose chemotherapy in these patients. OUTLINE: This is a randomized study. Patients are stratified by stage of disease. Peripheral blood stem cells (PBSC) are collected after mobilization with filgrastim (G-CSF), administered subcutaneously or IV, twice daily beginning 3 days before collection and continuing until collection is complete. All patients receive conventional-dose adjuvant chemotherapy, probably comprising doxorubicin IV, cyclophosphamide IV, and fluorouracil IV over 1 hour on days 1, 22, 43, and 64. Patients are then randomized to receive 1 of 2 treatment arms of high-dose chemotherapy. (Arm I closed to accrual as of 4/6/2006.) Arm I (ACT) (closed to accrual as of 4/6/2006): Patients receive doxorubicin IV over 24 hours on days -9 to -6, cyclophosphamide IV over 2 hours on day -5, and paclitaxel IV over 24 hours on day -2. PBSC are reinfused on days -2 and 0. G-CSF is administered beginning on day 0 and continuing until blood counts recover. Arm II (STAMP V): Patients receive cyclophosphamide IV, carboplatin IV, and thiotepa IV over 24 hours on days -7 to -4. PBSC are reinfused and G-CSF is administered as in arm I. Within 4-6 weeks of day 0 of high-dose chemotherapy, patients with estrogen and/or progesterone receptor positive tumors receive oral tamoxifen twice daily for 5 years. Patients are also randomized to receive a bisphosphonate comprising pamidronate IV every 4 weeks for 2 years. Quality of life is assessed before therapy, at 30 days after high-dose chemotherapy, and at 6 and 12 months. Patients are followed every 3 months for 1 year and then every 6 months for at least 10 years. PROJECTED ACCRUAL: A total of 100 patients will be accrued for this study within 3 years.