Benefits of zoledronic acid compared with placebo in breast cancer patients with bone metastases based on analysis of pain, analgesic use, and performance status

Abstract

10653 Background: We previously reported that zoledronic acid significantly reduced skeletal complications by 39% compared with placebo in breast cancer (BC) patients with bone metastases in a multicenter randomized trial conducted in Japan. To assess the effect of zoledronic acid in the maintenance of patient’s mobility or autonomy, we conducted a retrospective analysis of pain, analgesic use, and performance status (PS) among patients of this trial. Methods: 228 women with bone metastases were randomized to 4 mg zoledronic acid (n = 114) or placebo (n = 114) every 4 weeks for 1 year. At baseline and every 4 weeks during treatment, pain scores were assessed using the Brief Pain Inventory (BPI) on a scale of 0 to 10, and analgesic use was scored on a 4-point scale from none (0) to strong narcotics such as morphine (4). Eastern Cooperative Oncology Group (ECOG) PS was assessed at baseline and at study end. Results: Unlike patients receiving placebo who’s pain scores increased, patients treated with zoledronic acid had a significant decrease from baseline BPI composite pain score from week 4 to week 52: mean decrease of 0.86 in the zoledronic acid group at week 52 versus a mean increase of 0.62 in the placebo group; P < .05. Patients treated with zoledronic acid had very little change in analgesic scores, whereas patients in the placebo group had a mean increase in analgesic score (approximately 0.5) by study end. Shift table analysis of ECOG PS showed that 61% of patients in the zoledronic acid group had no change in PS, and 28% had worsening of ECOG PS of at least 1 grade from baseline to study end. In comparison, 54% of patients in the placebo group had no change in PS, and 36% had worsening of PS. Approximately 10% of patients in both treatment groups had an improvement in PS. Conclusions: This analysis shows that treatment with zoledronic acid reduced pain and prevented a worsening of ECOG PS in a larger percentage of patients compared with placebo, consistent with the demonstrated reduction in the rate of skeletal complications. This suggests that zoledronic acid may improve quality of life and maintain autonomy and mobility in breast cancer patients with bone metastases. No significant financial relationships to disclose.