The ODYSSEY TRIAL Phase IV Trial Evaluating the Palliative Benefit of Pamidronate or Zoledronic Acid in Breast Cancer

Metastatic breast cancer patients with bone involvement who are at high-risk of subsequent skeletal related event (SRE), defined as radiotherapy or surgery to the bone, pathological fracture, spinal cord compression, or hypercalcemia (as reflected through: elevated sCTX or bone pain or a prior SRE despite receiving standard bisphosphonate therapy) should experience a decrease in the surrogate marker, sCTX, at week 12 if switched to zoledronic acid compared with those patients who continue on intravenous pamidronate (i.e. current standard of care). The investigators propose that a drop in sCTX will correlate with improved pain, quality of life and a reduced incidence of further SREs.