Effect of bisphosphonates on local recurrence of giant cell tumor of bone: a meta-analysis

Postoperative Fracture Risk in Giant Cell Tumor: A Case Report and Review of Literature

Giant cell tumor (GCT) of the proximal femur poses various challenges in its management and recurrence. We present a rare case of GCT of proximal femur in which recurrence and coxa vara deformity were encountered after index surgery. Management of the recurrence was done with intramedullary fixation with extended curettage and bone grafting. Different aspects of management such as the role of defect size, adjuvants, bone cement/bone graft, implants, and bisphosphonates have been highlighted in this article.

Effect of bisphosphonates on bone giant cell tumor recurrence: a meta-analysis

Background

We examined the impact of bisphosphonates as adjuvant therapy on the recurrence of giant cell bone tumors and the impact of various tumor stages and surgical techniques on this effect. Following a thorough examination of the literature up to January 2022, 10 studies including 601 adults with giant cell tumors of the bone were reported; 295 of these subjects received bisphosphonates as adjuvant therapy following surgery, and 306 served as the control group. To examine the possibility of lowering the recurrence of giant cell bone tumors, a comparison between bisphosphonates and a control group was made. In order to evaluate the impact of bisphosphonates as adjuvant therapy on the recurrence of the giant cell bone tumor, odds ratios (OR) with 95% confidence intervals (CIs) were determined. Additionally, the dichotomous technique with a random or fixed-effect model was used to examine the effects of various tumor stages and pertinent surgical procedures.

Results

Patients with giant cell tumors of the bone who received bisphosphonates as adjuvant therapy had significantly lower postoperative recurrence rates outcomes in all subjects with giant cell tumor of bone (OR 0.19; 95% CI 0.12–0.31, p = 0.001), patients with stage I–II giant cell tumors of the bone (OR 0.29; 95% CI 0.11–0.76, p = 0.01), patients with stage III giant cell tumors of the bone (OR 0.17; 95% CI 0.07–0.42, p < 0.001); and post-intralesional curettage (OR 0.18; 95% CI 0.06–0.49, p < 0.001) compared to control. Bisphosphonates were used in participants with giant cell tumors of the bone after broad excision, but there was no discernible difference between the two groups in terms of postoperative recurrence outcomes (OR 0.66; 95% CI 0.11–3.91, p = 0.65).

Conclusions

In patients with giant cell tumors of the bone after intralesional curettage, the use of bisphosphonates as adjuvant therapy may lower the incidence of postoperative recurrence outcomes, but no appreciable difference was identified after extensive resection. According to the observed relationship, using bisphosphonates is advised to lower the likelihood of postoperative recurrence that can happen in patients with giant cell tumors of the bone.

Simvastatin Possesses Antitumor and Differentiation-Promoting Properties That Affect Stromal Cells in Giant Cell Tumor of Bone

Giant cell tumor of bone (GCTB) is a locally aggressive destructive bone lesion. The management of pulmonary metastasis and local recurrence after the surgical treatment of GCTB remains a challenge. Pathologically, stromal cells in GCTB are known as primary neoplastic cells and are recognized as incompletely differentiated preosteoblasts. Therefore, inducing GCTB stromal cells to differentiate into cells with a mature osteoblastic phenotype may stop tumor growth and recurrence. In this study, we aimed to investigate how simvastatin, a clinically approved and commonly used statin that has been known to promote the maturation of cells of the osteogenic lineage, affects GCTB stromal cells. We found that simvastatin effectively inhibited cell viability by suppressing proliferation and by inducing apoptosis in GCTB stromal cells. Moreover, simvastatin treatment upregulated the expression of genes related to osteogenic maturation, such as runt-related transcription factor 2, osteopontin, and osteocalcin, and increased the mineralization of the extracellular matrix in GCTB stromal cells. Ingenuity pathway analysis was used to discover that the vitamin D receptor pathway was involved in the simvastatin-induced osteogenic differentiation of GCTB stromal cells by upregulating the 1,25-dihydroxyvitamin D metabolism. Taken together, this in vitro study demonstrates the antitumor and differentiation-promoting effects of simvastatin on GCTB stromal cells and suggests the possibility of using simvastatin as an adjuvant therapy for GCTB. These findings support further clinical investigation of the efficacy of using simvastatin as an adjuvant therapy for GCTB to reduce recurrence and distant metastasis after surgical treatment. © 2019 Orthopedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:297-310, 2020.

Axial giant cell tumor - current standard of practice

Giant cell tumors of bone are relatively rare in the axial skeleton, accounting for approximately 6.7% of all cases. Due to their anatomical complexity, difficult access and proximity to vital neurovascular structures, management of these tumors poses a huge challenge on the treating surgeon. Several data series reported on axial GCTB involve short series of limited cases with varied methods used in their local control due to which, proper guidelines are unavailable for the management of such difficult cases. Though the present data support the use of denosumab for effective management of these lesions but there is varied consensus on dosage and duration of treatment. This review article summarizes the basic features and treatment modalities related to axial GCTB stressing on multidisciplinary approach to achieve optimum outcomes.