21 July, 2014
Bone antiresorptives, mostly bisphosphonates, are used in the treatment of metastatic bone disease from solid malignancies to reduce bone destruction, pain and skeleton-related events (SREs). Von Moos and colleagues  have reported pooled results from three randomized, identically designed, double-blind trials comparing subcutaneous denosumab (120 mg every 4 weeks) and intravenous zoledronic acid (4 mg/month) in patients with bone metastases from breast cancer (n = 2406), castration-resistant prostate cancer (n = 1901) or other solid tumors (n = 1597). The endpoints were pain severity, pain interference, health-related quality of life and analgesic use. Onset of moderate/severe pain was delayed by 1.8 months by denosumab treatment (hazard ratio (HR) 0.83; 95% CI 0.76–0.92; p < 0.001) and clinically meaningful increases in overall pain interference by 2.6 months (HR 0.83; 95% CI 0.75–0.92; p < 0.001) as compared with zoledronic acid. In addition, the need for strong opioids and reduction of health-related quality of life were less common with denosumab.
Breast cancer and prostate cancer are the most prevalent malignancies in women and men, respectively. Many adjuvant treatments are associated with reproductive hormone alterations which are involved in bone mass and quality. Thus, adjuvant aromatase inhibitors and gonadotropin-releasing hormone analogues are frequently used in women with non-metastatic breast cancer. Such treatments may accelerate bone loss and increase fracture risk. In breast cancer patients with osteopenia, subcutaneous denosumab administration (twice yearly) produces significant increases in bone mineral density (BMD), both at trabecular and cortical bone, without adverse events . Denosumab also increases BMD and reduces the incidence of new vertebral fractures among men under androgen-deprivation therapy for non-metastatic prostate cancer . In these non-metastatic cancers, zoledronic acid has similar protective anti-osteoporotic effects as denosumab, although some related adverse effects have been reported with this bisphosphonate [4,5].