Denosumab for effective tumor size reduction in patients with giant cell tumors of the bone: a systematic review and meta-analysis

Abstract

Background Denosumab is a human monoclonal antibody that is used in the successful treatment of giant cell bone tumors. These tumors are rare and, in principle, benign, but they are highly aggressive, locally advanced, and osteolytic bone tumors that can metastasize to the lungs. Denosumab is an effective treatment when these tumors cannot be surgically removed or when surgical resection is likely to lead to severe morbidity (e.g., loss of limbs or joints). The aim of this systematic review and meta-analysis was to investigate the patients with giant cell bone tumors who experienced tumor progression during treatment with denosumab and to compare them with patients who experienced reduction of their giant cell bone tumors during treatment with denosumab. Methods The Embase, Cochrane Library, and MEDLINE/PubMed databases were searched until February 28, 2018 for trials reporting the efficacy and safety of denosumab in patients with giant cell bone tumors. Results Thirty-three studies were reviewed, involving a total of 350 patients who had giant cell bone tumors and were treated with denosumab. Of the 33 studies, 67% of the patients were from open-label phase II studies, 27% from case series, and 6% from case reports. The response rate for denosumab as a treatment for giant cell bone tumors was 95.3%, with statistical significance (P < 0.0001). Osteonecrosis of the jaw was statistically the most common adverse event for denosumab treatment in open-label phase II studies (P < 0.0001). No treatment-related deaths occurred in the reviewed studies. Conclusion Cumulative evidence supports the addition of surgery to optimal medical therapy with denosumab to reduce tumor size, clinical symptoms, and mortality among patients with giant cell bone tumors.