Zoledronic acid given upfront maintains BMD in postmenopausal breast cancer patients

Study Type: Therapy
OE Level of Evidence: 2
Journal Level of Evidence: N/A
Dr. Adam M. Brufsky discusses the use of adjuvant zoledronic acid to maintain bone mass in postmenopausal breast cancer patients.
602 postmenopausal women receiving adjuvant letrozole were randomized either to upfront zoledronic acid or delayed-start zoledronic acid to determine which method minimizes bone-loss. At 5 years Please login to view the rest of this report. Please login to view the rest of this report.
Funding: Industry funded
Sponsor: Novartis Pharmaceuticals Corporation (East Hanover, New Jersey)
Conflicts: Consultant
Why was this study needed now?
Postmenopausal women with early breast cancer receiving aromatase inhibitor (AI) therapy are at risk of developing progressive bone loss within the first year of treatment. Evidence from prior studies have displayed that zoledronic acid, a bisphosphonate containing nitrogen, is effective in preventing bone loss in breast cancer patients. However, information regarding at what point in time a patient should begin to take zoledronic acid, in order to get best results is still unclear. Hence, this report aimed on determining whether prevention of bone loss with upfront zoledronic acid was more effective than delayed zoledronic acid.
What was the principal research question?
Was upfront administration of zoledronic acid more effective at preventing bone loss in postmenopausal breast cancer patients than delayed-start administration, when assessed over a 5 year period?
Population: 602 postmenopausal women with histories of early stage, estrogen or and progesterone receptor-positive breast cancer who had been receiving 2.5 mg of letrozole per day for 5 years.
Intervention: Upfront Group: Patients received 4 mg of zoledronic acid intravenously every 6 months, starting right after randomization occurred (Mean age: 61.4 +/- 9.28) (n=301; 108 patients completed follow-up).
Comparison: Delayed Group: If the lumbar spine (LS) or total hip T score fell to less than -2, or if a clinical non-traumatic fracture occurred, or an asymptomatic vertebral fracture occurred and was noticed during the follow up at 36 months, then only at that point did patients begin receiving 4 mg of zoledronic acid intravenously every 6 months (Mean age: 61.0 +/- 8.92) (n=301; 175 patient completed follow-up).
Outcomes: The outcomes measured were difference in percentage change in LS and total hip BMDs from baseline to 12, 24, 36, and 61 months following start of treatment, changes in serum N-telopeptide (NTX) and serum bone-specific alkaline phosphatase (BSAP) concentrations from baseline to 12, 24, 36, and 61 months following start of treatment, fracture incidence, and incidence rates of disease recurrence (measured using Kaplan-Meier analysis).
Methods: RCT: multi center
Time: LS and total hip BMD, NTX and BSAP concentration were measured at baseline, and 12, 24, 36, and 61 months following the start of treatment. Fracture incidence and rates of disease recurrence were measured at month 36.
What were the important findings?
What should I remember most?
How will this affect the care of my patients?
The authors responsible for this critical appraisal and ACE Report indicate no potential conflicts of interest relating to the content in the original publication.