Abstract 154P
Background
Giant cell bone tumors (GCT) are primary locally aggressive neoplasms that occasionally manifest with distant metastasis. Denosumab, a fully humanized monoclonal antibody against the RANK ligand, is indicated for its effectiveness in the treatment of unresectable or metastatic GCT.
Methods
An observational, descriptive, cross-sectional, and retrospective study was conducted at the Instituto Nacional de Enfermedades Neoplásicas de Lima, Peru evaluating patients diagnosed between 2018 and 2022 who received neoadjuvant denosumab treatment.
Results
In this study of 34 patients with an average age of 30.5 years, predominantly females (55.9%), the average time from symptom onset to diagnosis was 7 months. Common symptoms included pain (91.2%), swelling (64.7%), and fractures (14.7%). The most frequent tumor locations were the femur, fibula, sacrum, and tibia, each accounting for 11.8%. No metastases were observed at onset. Soft tissue involvement occurred in 50% of patients, joint involvement in 17.2%, fractures in 13.1%, and adjacent bone involvement in 17.2%. Radiologically, 8.8% had type II disease, 88.3% had type III by the Campanacci classification, and 2.9% were undetermined. By Enneking classification, 2.9% had type I, 88.2% had type III, and 8.9% were undetermined. Regarding neoadjuvant Denosumab treatment, 35.35% experienced adverse effects, mostly grade 1, including bone pain, hypocalcemia, and anemia. Surgical intervention was undergone by 58.8%, with 81% opting for conservative surgeries. Only 20.6% received radiotherapy. Follow-up studies showed 96.6% with no progression, 97.1% remained alive, and 2.9% resulted in death.
Conclusions
This is the first study in Peru that provides a detailed perspective on neoadjuvant Denosumab treatment in patients with GCT. Treatment with denosumab has allowed conservative surgeries to be performed in the majority of previously inoperable patients. These findings support the feasibility and effectiveness of the neoadjuvant approach with Denosumab, with a low incidence of significant adverse effects.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Instituto Nacional de Enfermedades Neoplásicas de Lima, Peru.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.