Adjuvant treatment with zoledronic acid after extensive curettage for giant cell tumours of bone.

Background: Giant cell tumours (GCT) of bone are benign neoplasms associated with a high rate of local recurrence after extensive intra-lesional curettage. Recently, understanding of the biological molecular availability of strong anti-osteoclastic drugs has suggested their potential value in reducing local recurrences after curettage. Through a phase II clinical trial, we investigated the effect of a short treatment with zoledronic acid (ZOL) after intra-lesional curettage of GCT, as well as local recurrence and tolerance of the treatment.

Methods And Patients: Twenty-four patients were enrolled in a multicentre, phase 2 study. The patients were treated with extensive intra-lesional curettage followed by five courses of ZOL (4 mg IV every 3 weeks). The clinical and biological tolerance of each patient was assessed. Patients were reviewed clinically and by X-ray every 6 months until the end of the study (36 months).

Results: Eighteen out of 20 patients reported side-effects with ZOL, mainly grade 1 and 2 effects. The local recurrence rate was 15%; three patients had a recurrence, one at 4 months (huge GCT of the sacrum), one at 24 months (patient who discontinued the treatment after the first course of ZOL), and one after the observational period, at 58 months. Finally, local relapse-free survival was 82 ± 9% at 60 months.

Conclusion: Short adjuvant treatments with ZOL after extensive intra-lesional curettage of GCT were associated with a low rate of recurrence but did not prevent local recurrence in this study. No serious general adverse effects were observed. More studies are needed to evaluate the potential benefit of medical bisphosphonate injections combined with intra-lesional curettage in the treatment of GCTB.