Phase II trial evaluating the palliative benefit of second-line zoledronic acid in breast cancer patients with either a skeletal-related event or progressive bone metastases despite first-line bisphosphonate therapy.

Purpose This study evaluated whether additional palliative benefits could be derived from the second-line use of the more potent bisphosphonate zoledronic acid in metastatic breast cancer patients with either progressive bone metastases or skeletal-related events (SRE), despite first-line therapy with either pamidronate or clodronate. Patients and Methods This prospective study evaluated the impact of second-line zoledronic acid on pain, quality of life, and markers of bone turnover (for example, urinary N-telopeptide [NTX]). Patients received monthly zoledronic acid (4mg) for 3 months. Study evaluations were made weekly during the first month and again at week 8. No changes in chemotherapy or endocrine therapy were allowed in the month before or after commencing study treatment. Results Thirty-one women completed this study. By week 8, patients had experienced significant improvements in pain control (P < .001). There was a downward trend in urinary NTX levels over the same time period (P = .008). Overal...