ASO Visual Abstract: Preoperative Denosumab Therapy against Giant Cell Tumor of Bone Is Associated with an Increased Risk of Local Recurrence after Curettage Surgery

Introduction Denosumab has been shown to be highly effective at suppressing the progression of giant cell tumor of bone (GCTB). However, recent studies have observed a potential increased risk of local recurrence after surgery following the use of denosumab, raising concerns on the use of this agent against GCTB in combination with surgery. Methods We retrospectively reviewed the medical records of 234 patients with GCTB who were surgically treated at multiple institutions from 1990 to 2017. Patient background, tumor characteristics, treatment methods, local recurrence-free survival rate, distant metastasis rate, oncologic outcome, and limb function at final follow-up were analyzed and compared between cases treated with and without denosumab. Results The 3-year local recurrence-free survival rate was significantly lower in patients who underwent preoperative denosumab therapy (35.3%) compared with those treated without denosumab (79.9%) ( P < 0.001). Among patients who were preoperatively treated with denosumab, those who had a local recurrence all underwent curettage surgery. Conclusions Preoperative denosumab therapy in combination with curettage surgery was significantly associated with an increased risk of local recurrence in Campanacci grade 3 tumors. Our data suggest that clinicians seeing GCTB patients should be aware to this increased risk when planning preoperative denosumab therapy.