Efficacy of Neoadjuvant Denosumab on Tumor Recurrence, Ossification, and Surgical Outcomes in Patients With Grade III Giant Cell Tumor of Bone: A Prospective, Non‐Randomized Comparative Interventional Study

Abstract

Abstract

BACKGROUND: Giant cell tumor of bone (GCTB) is a rare, locally aggressive osteolytic neoplasm associated with a substantial risk of local recurrence and challenging surgical management. Denosumab, a monoclonal antibody, has emerged as a promising therapeutic option. This study evaluates the efficacy of denosumab as a neoadjuvant therapy in patients with Grade III GCTB, with particular emphasis on tumor recurrence, ossification, and surgical outcomes. METHODS: In this prospective, non-randomized comparative interventional study, 34 adults with histologically confirmed Campanacci Grade III GCTB were enrolled and prospectively followed. Sixteen patients received neoadjuvant denosumab and 18 contemporaneous patients underwent surgery without neoadjuvant denosumab. Treatment allocation was based on routine clinical decision-making and patient-specific factors rather than randomization. RESULTS: During the 18-month follow-up period, local recurrence occurred in 2 of 16 patients (12.5%) in the denosumab intervention group and in 8 of 18 patients (44.4%) in the comparison group (p = 0.063). Radiological ossification was observed in all patients in the denosumab group and in none of the patients in the comparison group. Curettage and cementation were performed in 14 patients (87.5%) in the intervention group and 12 patients (66.7%) in the comparison group; this difference was not statistically significant (p = 0.233). Qualitative histopathological assessment of available specimens from denosumab-treated patients demonstrated marked depletion or disappearance of osteoclast-like giant cells, accompanied by treatment-related changes including new bone formation, fibrosis, and hemorrhage. CONCLUSION: In this study, neoadjuvant denosumab was associated with complete radiological ossification, qualitative histopathological changes characterized by marked depletion of osteoclast-like giant cells, and numerically lower observed local recurrence and greater use of curettage and cementation, although the latter two between-group differences were not statistically significant.