CORR Insights®: Is a Short-course of Preoperative Denosumab as Effective as Prolonged Therapy for Giant Cell Tumor of Bone?

Progress on Denosumab Use in Giant Cell Tumor of Bone: Dose and Duration of Therapy

Giant cell tumor of bone (GCTB) is an aggressive non-cancerous bone tumor associated with risks of sarcoma and metastasis. Once malignancy occurs, the prognosis is generally poor. Surgery remains the main treatment for GCTB. Multidisciplinary management is a feasible option for patients wherein surgical resection is not an option or for those with serious surgery-related complications. Denosumab is an anti-nuclear factor kappa B ligand approved for the treatment of postmenopausal women with osteoporosis, bone metastases, and advanced or inoperable GCTB. However, the guidelines for treating GCTB are unclear; its short-term efficacy and safety in inoperable patients have been demonstrated. Lengthier therapies (high cumulative doses) or pre-operative adjuvant therapy may be associated with severe complications and high local recurrence rates. Short-term administration helps attain satisfactory local control and functionality. As a result, lately, the impact of different doses and lengths of treatment on the efficacy of denosumab in GCTB treatment, the incidence of complications, and recurrence rates have gained attention. The efficacy and safety of denosumab against GCTB, its impact on imaging assessment, related complications, and recurrence of GCTB were previously reviewed. For further research direction, this paper reviews the progress of studies evaluating the impact of the dose and duration of denosumab therapy for GCTB.

Surgical challenges, novel techniques, and systemic treatment of giant cell tumour of bone of the distal radius

Aims

Giant cell tumour of bone (GCTB) treatment changed since the introduction of denosumab from purely surgical towards a multidisciplinary approach, with recent concerns of higher recurrence rates after denosumab. We evaluated oncological, surgical, and functional outcomes for distal radius GCTB, with a critically appraised systematic literature review.

Methods

We included 76 patients with distal radius GCTB in three sarcoma centres (1990 to 2019). Median follow-up was 8.8 years (2 to 23). Seven patients underwent curettage, 38 curettage with adjuvants, and 31 resection; 20 had denosumab.

Results

Recurrence rate was 71% (5/7) after curettage, 32% (12/38) after curettage with adjuvants, and 6% (2/31) after resection. Median time to recurrence was 17 months (4 to 77). Recurrences were treated with curettage with adjuvants (11), resection (six), or curettage (two). Overall, 84% (38/45) was cured after one to thee intralesional procedures. Seven patients had 12 months neoadjuvant denosumab (5 to 15) and sixmonths adjuvant denosumab; two recurred (29%). Twelve patients had six months neoadjuvant denosumab (4 to 10); five recurred (42%). Two had pulmonary metastases (2.6%), both stable after denosumab. Complication rate was 18% (14/76, with 11 requiring surgery). At follow-up, median MusculoSkeletal Tumour Society score was 28 (18 to 30), median Short Form-36 Health Survey was 86 (41 to 95), and median Disability of Arm, Shoulder, and Hand was 7.8 (0 to 58).

Conclusion

Distal radius GCTB treatment might deviate from general GCTB treatment because of complexity of wrist anatomy and function. Novel insights on surgical treatment are presented in this multicentre study and systematic review. Intralesional surgery resulted in high recurrence-rate for distal radius GCTB, also with additional denosumab. The large majority of patients however, were cured after repeated curettage. Cite this article: Bone Jt Open 2022;3(7):515–528.

Updated concepts in treatment of giant cell tumor of bone

PURPOSE OF REVIEW

Giant cell tumors of bone (GCTB) are intermediate, locally aggressive primary bone tumors. For conventional GCTB, surgery remains treatment of choice. For advanced GCTB, a more important role came into play for systemic therapy including denosumab and bisphosphonates over the last decade.

RECENT FINDINGS

In diagnostics, focus has been on H3F3A (G34) driver mutations present in GCTB. The most frequent mutation (G34W) can be detected using immunohistochemistry and is highly specific in differentiating GCTB from other giant cell containing tumors. PD-L1 expression can be used as biological marker to predict higher recurrence risks in GCTB patients.The use of bisphosphonate-loaded bone cement is under investigation in a randomized controlled trial. A new technique consisting of percutaneous microwave ablation and bisphosphonate-loaded polymethylmethacrylate cementoplasty was proposed for unresectable (pelvic) GCTB.Increased experience with use of denosumab raised concern on elevated recurrence rates. However, conclusions of meta-analyses should be interpreted with risk of indication bias in mind. Several small studies are published with short-course denosumab (varying from 3 to 6 doses). One small trial directly compared denosumab and zoledronic acid, with no statistical differences in radiological and clinical outcome, and nonsignificantly higher recurrence rate after denosumab. As bisphosphonates directly target neoplastic stromal cells in GCTB, larger directly comparative trials are still warranted.

SUMMARY

Neoadjuvant denosumab is highly effective for advanced GCTB, and a short-course is advised to facilitate surgery, whereas increased recurrence rates remain of concern. Randomized controlled trials are conducted on bisphosphonate-loaded bone cement and on optimal dose and duration of neoadjuvant denosumab. PD-L1 could be a potential new therapy target in GCTB.