Zoledronate, Calcium, and Vitamin D in Preventing Bone Loss in Women Receiving Adjuvant Chemotherapy for Breast Cancer

RATIONALE: Zoledronate plus calcium and vitamin D may prevent bone loss in patients receiving adjuvant chemotherapy for breast cancer. It is not yet known which regimen is more effective in preventing bone loss. PURPOSE: This randomized phase III trial is comparing two regimens of zoledronate plus calcium and vitamin D to see how well they work in preventing bone loss in women who are receiving adjuvant chemotherapy for breast cancer.

OBJECTIVES: * Compare the bone mineral density in the lumbar spine after 12 and 36 months of therapy with zoledronate, calcium, and cholecalciferol (vitamin D) in women with breast cancer receiving adjuvant chemotherapy. OUTLINE: This is a randomized, open-label, multicenter study. Patients are stratified according to intent to treat with tamoxifen (yes vs no) and node status (negative vs positive vs unknown \[for patients receiving neoadjuvant therapy\]). Patients are randomized to 1 of 2 treatment arms. * Arm I: Beginning on the first day of adjuvant chemotherapy (or within 3 months after the first day), patients receive zoledronate IV over at least 15 minutes once every 3 months during months 1-24 and oral calcium and oral cholecalciferol (vitamin D) daily during months 1-36. * Arm II: Beginning on the first day of adjuvant chemotherapy (or within 3 months after the first day), patients receive oral calcium and oral vitamin D daily during months 1-36 and zoledronate IV over at least 15 minutes once every 3 months during months 13-36. PROJECTED ACCRUAL: Approximately 400 patients (200 per treatment arm) will be accrued for this study within 24 months.