Every Six-Month versus Single-Dose Adjuvant Zoledronate in Early Breast Cancer

Area of Science:

• Oncology
• Pharmacology
• Clinical Trials

Background:

• Previous 3-year data indicated a single zoledronate infusion offered superior patient convenience, reduced toxicity, and fewer discontinuations compared to infusions every 6 months.
• This study presents the final, pre-specified 5-year follow-up data from the randomized trial.

Purpose of the Study:

• To compare the long-term efficacy and safety of a single zoledronate infusion versus infusions every 6 months in postmenopausal women with early breast cancer.
• To evaluate recurrence-free survival, bone metastasis-free survival, and overall survival at 5 years.

Main Methods:

• A randomized trial involving postmenopausal women with early breast cancer.
• Patients received either a single zoledronate infusion (4 mg IV) or infusions every 6 months for 3 years.
• Secondary outcomes assessed at 5 years included survival rates, osteonecrosis of the jaw, and fragility fractures.

Main Results:

• No significant differences were observed between the single-infusion and 6-monthly infusion groups in recurrence-free survival (88.7% vs. 84.1%), bone metastasis-free survival (90.6% vs. 86.0%), or overall survival (91.6% vs. 88.0%) at 5 years.
• The incidence of osteonecrosis of the jaw was 0% in both groups.
• Fragility fracture rates were similar, with 5% in the single-infusion group and 2% in the 6-monthly infusion group.

Conclusions:

• Extended 5-year follow-up confirms no significant difference in survival outcomes between a single zoledronate infusion and treatment every 6 months.
• A single zoledronate infusion maintains its advantages of convenience and reduced toxicity without compromising long-term efficacy in early breast cancer patients.