title: Bisphosphonates reduce local recurrence in extremity giant cell tumor of bone: a case-control study.
abstract: BACKGROUND
  Giant cell tumor (GCT) of bone is a benign but locally aggressive tumor that is characterized by the presence of mononuclear stromal cells and multinucleated giant cells. Although topical adjuvants have been used in the past, local recurrence following intralesional excision of GCT of bone continues to remain a problem. The use of bisphosphonates as an anti-osteoclastic agent in the management of osteolytic bone metastases is well accepted. Furthermore in vitro studies have shown that bisphosphonates also induce apoptosis in GCT stromal cells. Therefore our clinical study aims to investigate whether the administration of bisphosphonate as an adjuvant can further decrease local recurrence following the surgical treatment of GCT of bone.
  
  
  METHODS
  A retrospective case-control study was performed between 1988 and 2004. Forty-four patients with histological diagnosed appendicular GCT were included. Intralesional curettage or wide excision of the lesions was followed with cementation or biological reconstruction. Additional intravenous and oral bisphosphonates were given peri-operatively to 24 patients who were treated between 1998 and 2004. The average follow-up of the control group was 115 months while that of the treatment group was 48 months.
  
  
  RESULTS
  In the bisphosphonate treated group, 1 of 24 patients (4.2%) developed local recurrence. In the control group, 6 of 20 patients (30%) developed local recurrence. The difference in the recurrence rate was statistically significant between the bisphosphonate treatment group and the control group (Log Rank test p=0.056). The effect of reduction of local recurrence was significant in patients with stage III diseases. Patients treated with bisphosphonate did not report any untoward effects.
  
  
  CONCLUSIONS
  Clinical use of bisphosphonates as an adjuvant therapy for giant cell tumor of bone demonstrated a lower local recurrence rate. The clinical response seems to be more promising in stage III diseases.
authors.affiliation: Department of Orthopaedics and Traumatology, Prince of Wales Hospital, Shatin, Hong Kong. tself@ort.cuhk.edu.hk
authors.forename: Lung Fung
authors.initials: LF
authors.lastname: Tse
authors.forename: Kwok Chuen
authors.initials: KC
authors.lastname: Wong
authors.forename: Shekhar Madhukar
authors.initials: SM
authors.lastname: Kumta
authors.forename: Lin
authors.initials: L
authors.lastname: Huang
authors.forename: Tsun Cheung
authors.initials: TC
authors.lastname: Chow
authors.forename: James Francis
authors.initials: JF
authors.lastname: Griffith
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D016022:Case-Control Studies; D004164:Diphosphonates / Q000494:pharmacology*; D005121:Extremities / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D018212:Giant Cell Tumor of Bone / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000517:prevention & control*; D012189:Retrospective Studies
chemical_list: D004164:Diphosphonates