A Clinical Trial Comparing Adjuvant Clodronate Therapy vs Placebo in Early-Stage Breast Cancer Patients Receiving Systemic Chemotherapy and/or Hormonal Therapy or No Therapy

OBJECTIVES:

• Determine whether clodronate administered alone or in addition to adjuvant chemotherapy and/or hormonal therapy improves disease-free survival in women with early stage breast cancer.
• Determine whether clodronate reduces the incidence of skeletal metastases and non-skeletal metastases in these patients.
• Determine whether clodronate improves overall and relapse-free survival in these patients.
• Determine whether clodronate reduces the incidence of skeletal morbidity (e.g., skeletal fractures, hypercalcemia, skeletal pain, need for radiotherapy, spinal cord compression) in these patients.
• Investigate the relevance of serum markers of bone turnover as a prognostic factor for the development of bone metastasis in these patients.

OUTLINE: This is a randomized, double-blind, placebo-controlled study. Patients are stratified by age (under 50 vs 50 and over), number of positive lymph nodes (0 vs 1-3 vs 4 or more), and hormone receptor status (estrogen receptor [ER] and progesterone receptor [PR] negative vs ER and/or PR positive). Patients are randomized to one of two treatment arms.

Patients in both arms commence treatment within 2 weeks of randomization and continue treatment for 3 years in the absence of bone metastasis or unacceptable toxicity. Study medication must be continued in the case of documented visceral or soft tissue metastasis or other event without skeletal metastasis.

Patients in both arms may also receive adjuvant chemotherapy and/or tamoxifen at the discretion of the protocol investigator. Patients receiving hormonal therapy begin hormonal therapy within 3-12 weeks after the last dose of chemotherapy and continue for a minimum of 5 years.