Saad, F., & Eastham, J. (2010). Zoledronic acid improves clinical outcomes when administered before onset of bone pain in patients with prostate cancer. Urology, 76(5), 1175–1181.

To evaluate the effect of zoledronic acid (ZOL) on skeleton-related events (SREs) and bone pain; to determine if baseline bone pain affects clinical outcomes of patients receiving ZOL

Patients were initially randomized to receive placebo or ZOL 4 mg by infusion every three weeks for up to 24 months. Bone pain was assessed at six-week intervals, and investigators recorded data about radiotherapy or surgery to bone, changes in antineoplastic treatment of bone pain, and SREs (e.g., pathologic fracture, spinal cord compression).

• The sample was composed of 422 patients.
• Mean patient age was 72.5 years.
• All patients were male.
• All patients had prostate cancer; 73% had bone pain at baseline, with an average BPI score of 2.84.

• Multisite
• Outpatient
• The report did not state the study locations.

Secondary analysis of phase III placebo-controlled randomized study

Brief Pain Inventory (BPI)

Bone pain increased over time in all patients. However, compared to patients receiving placebo, patients receiving ZOL reported smaller increases in mean BPI composite scores throughout 24 months (p < 0.04). This difference was most significant (p = 0.003) at three months. This difference was seen whether or not patients had reported bone pain at baseline. In patients with pain at baseline, ZOL lengthened the median interval to first SRE by about six months, compared with placebo (p = 0.087). In patients without bone pain at baseline, patients on ZOL had not had SREs at the 24-month follow-up. Those who were on placebo had a median time to SRE of 15 months (p = 0.04). There was no difference in median overall survival between placebo and ZOL groups.

ZOL postponed the onset of severe bone pain and skeletal events in patients with prostate cancer.

• The study did not discuss or analyze the medications taken for pain over the course of the study, so whether differences were due only to the use of ZOL versus other pain management is unclear.
• Authors note that SREs may have been underreported.

This study highlights the importance of intervention before symptoms of bone involvement develop. Some current guidelines have recommended ZOL for treatment of bone metastases; however, this study suggests that administration of ZOL prior to known bone metastases may reduce pain and delay skeletal events. Nurses can advocate for prophylactic approaches to manage these problems in patients with prostate cancer.