Evaluation of Local Recurrence in Giant-Cell Tumor of Bone Treated by Neoadjuvant Denosumab

Background: Giant-cell tumor of bone (GCTB) is a locally aggressive primary benign tumor presenting as an expansile osteolytic lesion affecting the epiphysis of long bones. Denosumab halts the osteolysis by giant cells thereby downstaging the tumor, helping in performing less morbid procedures to remove the tumor. Our aim was to report the incidence of local recurrence (LR) in patients operated following neoadjuvant denosumab, to investigate factors associated with LR following extended curettage for GCTB, and to compare the postoperative functional and oncological outcome of patients operated with and without neoadjuvant denosumab. Methods: A total of 123 patients with a mean age of 29.6 years undergoing extended curettage for GCTB were retrospectively divided into group 1 receiving neoadjuvant denosumab and group 2 operated without denosumab. The mean follow-up period was 35 months. The perioperative characteristics and outcome were compared between the two groups and the factors for LR of GCTB were analyzed. Results: The incidence of LR among patients operated after neoadjuvant denosumab therapy was 42.8% and was significantly high compared to that in patients without denosumab (p < 0.001). On multivariate logistic regression analysis, use of denosumab as a neoadjuvant was the only factor independently associated with LR following surgery (p = 0.002). Patients treated with denosumab had a lower LR-free survival rate (log-rank, p = 0.018). Conclusions: Denosumab was independently associated with increased LR following surgery for GCTB. Denosumab has to be used cautiously in patients in whom the burden of downstaging the disease outweighs the possible chance of LR.