Pain on movement and pain at rest decrease after zoledronic acid infusion in patients with bone metastases due to breast or prostate cancer

Abstract

18582 Background: There is no study on bisphosphonates assessing separately pain at rest and incident pain. Aim of the study was to evaluate the reduction in pain at rest and incident pain after treatment (up to 6 infusions) with 4 mg zoledronic acid (ZA) I.V. every 28 days in patients with bone metastases. Methods: All consecutive patients with bone metastases from breast or prostate cancer starting ZA treatment (August 2002 - May 2004) at NCI of Milan were enrolled in this observational prospective longitudinal study. Pain at rest and incident pain referred to the prior week were measured by a six level verbal scale (0–5 score) at baseline and on each infusion as well as at follow-up visit (2 weeks after every infusion). The two main endpoints (estimated reduction in pain at rest and incident pain) were defined as the difference between the baseline score and the average of all the post-treatment scores for each patient, and are presented with their respective 95% Confidence Interval. Positive values indicate reduction. Because of the potential confounding effect of analgesics intake, patients without any increase in analgesic consumption while on study were also analyzed as a separate subgroup. Results: 48 patients (mean age 66 years, 33 female), with breast (34) or prostate cancer (14) were enrolled. 30 patients underwent 4 to 6 infusions while 7 dropped out before the first follow-up visit. The analysis was performed on the 41 patients with at least one follow-up evaluation (average number of evaluations = 8.1 range = 1–13). The estimated reduction in pain at rest and incident pain was 0.55 (0.19–0.91) and 0.73 (0.31–1.14) respectively. In the 13 patients who did not report increased analgesic consumption, the estimated reduction was still substantial: 0.61 (0.25–0.97) 1.12 (0.41–1.83) respectively. Conclusions: This is the first study showing that in patients with painful multiple bone metastases, ZA reduces both pain at rest and incident pain in patients with painful bone metastases. [Table: see text]