Denosumab in Giant Cell Tumor of Bone: Multidisciplinary Medical Management Based on Pathophysiological Mechanisms and Real-World Evidence

Simple Summary

The widely accepted local therapy in extremity giant cell tumor of bone (GCTB) is surgery, in the form of extended intralesional curettage with adequate disease clearance and retention of the limb, wherever possible. Denosumab is a relevant therapy option for advanced GCTB, to benefit tumor response and surgical down-staging. Most GCTB patients with localized disease can be successfully treated with surgical curettage; patients with primary unresectable lesions or metastases may experience long-term clinical and radiological remission and pain control with denosumab treatment, and in this clinical situation, denosumab is currently the treatment of choice.

Abstract

(1) Despite the benign nature of the giant cell tumor of bone (GCTB), it shows a local recurrence rate of up to 50% and a chance of malignant transformation. The widely accepted local therapy in extremity GCTB is surgery, in the form of extended intralesional curettage with adequate disease clearance and retention of the limb, wherever possible. Denosumab, a human monoclonal antibody directed against the RANKL and associated inhibition of the RANKL pathway, is a relevant therapy option for advanced GCTB, to benefit tumor response and surgical down-staging. (2) The literature review of patients with GCTB treated with denosumab is performed via PubMed, using suitable keywords from January 2009 to January 2021. (3) Current indications for denosumab use are not definitively clear and unambiguous. Most GCTB patients with localized disease can be successfully treated with surgical curettage, and the role of denosumab in preoperative therapy in this patient population remains unclear. (4) However, patients with primary unresectable lesions or metastases may experience long-term clinical and radiological remission and pain control with denosumab treatment, and in this clinical situation, denosumab is currently the treatment of choice.

Diagnostic Utility of Genetic and Immunohistochemical H3-3A Mutation Analysis in Giant Cell Tumour of Bone

To validate the reliability and implementation of an objective diagnostic method for giant cell tumour of bone (GCTB). H3-3A gene mutation testing was performed using two different methods, Sanger sequencing and immunohistochemical (IHC) assays. A total of 214 patients, including 120 with GCTB and 94 with other giant cell-rich bone lesions, participated in the study. Sanger sequencing and IHC with anti-histone H3.3 G34W and G34V antibodies were performed on formalin-fixed, paraffin-embedded tissues, which were previously decalcified in EDTA if needed. The sensitivity and specificity of the molecular method was 100% (95% CI: 96.97–100%) and 100% (95% CI: 96.15–100%), respectively. The sensitivity and specificity of IHC was 94.32% (95% CI: 87.24–98.13%) and 100% (95% CI: 93.94–100.0%), respectively. P.G35 mutations were discovered in 2/9 (22.2%) secondary malignant GCTBs and 9/13 (69.2%) GCTB after denosumab treatment. We confirmed in a large series of patients that evaluation of H3-3A mutational status using direct sequencing is a reliable tool for diagnosing GCTB, and it should be incorporated into the diagnostic algorithm. Additionally, we discovered IHC can be used as a screening tool. Proper tissue processing and decalcification are necessary. The presence of the H3-3A mutation did not exclude malignant GCTB. Denosumab did not eradicate the neoplastic cell population of GCTB.

Functional outcome of surgical treatment of adults with extremity osteosarcoma after megaprosthetic reconstruction-single-center experience

BACKGROUND

Osteosarcoma is the most common primary malignant bone tumor in adults and is usually located in the long bones. Standard treatment consists of perioperative chemotherapy and radical surgical resection. Limb-sparing surgery using a variety of reconstructive techniques remains the gold standard.

METHODS

In our study, we retrospectively analyzed 90 adult patients operated at our institution between 2000 and 2017 for extremity osteosarcoma that underwent limb-sparing reconstruction with the megaprosthesis. Sixty-one patients underwent resection and reconstruction of the distal femur, 9 patients-proximal femur, 7 patients-proximal tibia, 5 patients-total femoral resection and reconstruction, 5 patients-proximal humeral resection, and 3 patients-other types of resection with endoprosthetic reconstruction. The median follow-up time was 41 months, median overall survival was 86 months (3-225 months), and progression-free survival was 81 months (1-86 months). Functional assessment was made on 48 out of 56 living patients, after endoprosthetic reconstruction. The assessment was made according to MSTS functional scale.

RESULTS

In 14 cases (15%), the endoprosthesis had to be explanted, or amputation was performed for local recurrence or septic complication. Due to a mechanical failure of the implant, we had to perform a revision in 5 patients (5%). Eighteen out of 74 patients with endoprosthesis died of the disease. The median MSTS score was 84% (53-100%), and the best result of 85% was achieved in patients after distal femoral resection with endoprosthetic reconstruction.

CONCLUSION

Careful planning of the treatment of patients with extremity osteosarcoma that is performed at the referral centers gives the possibility of long-term survival with a good and excellent functional result.

Denosumab treatment of inoperable or locally advanced giant cell tumor of bone - Multicenter analysis outside clinical trial

BACKGROUND

Giant cell tumor of bone (GCTB) is an osteolytic, locally aggressive, rarely metastazing bone tumor. This is a retrospective study evaluating a large series of GCTB patients treated with denosumab in routine practice in 6 European reference centers.

METHODS

Patients with locally advanced, unresectable or metastatic GCTB, treated with denosumab outside clinical trials were eligible. Primary end-point was progression-free survival (PFS) for all patients; secondary end-points were: type of surgery, relapse rate and event-free survival for patients after preoperative denosumab + surgery.

RESULTS

We identified 138 patients treated in the period 2011-2016. In 40/43 cases the diagnosis was confirmed by H3F3A gene mutation. Median follow-up time was 23 months (range 6-48). Primary tumor was located in lower limb (38%) - mostly in femur and tibia, in upper limb (34%), and in pelvis/axial skeleton/ribs (28%). 110 (80%) patients had primary tumors, 28 (22%) recurrent tumors after previous surgical procedures (+/- radiotherapy). 89/138 patients had locally advanced GCTB and underwent neoadjuvant denosumab. The median denosumab treatment duration was 8 months (median number of cycles 11), 98% had clinical benefit from therapy. 39 (44%) had wide en-bloc resection - WE (+implantation of the prosthesis in 17 cases), the other 50 (56%) cases had intralesional curettage - C. Progression after surgical treatment was observed in 19 patients, 16 of them after C (32%); 13 patients underwent denosumab re-challenge, and all responded. Two-year progression-free survival (PFS; from denosumab start) rate was 81%; 2-year EventFS (from surgery) was significantly better in WE group (93%) vs 55% in C group (p = 0.006). Treatment was well tolerated with only 2 cases of grade 3 toxicity and one osteonecrosis of the jaw.

CONCLUSION

Our retrospective study confirms that denosumab is extremely efficient in unresectable/metastatic disease as well as in a neoadjuvant setting. Our data confirm excellent efficacy and short-term tolerability of this drug. Our data suggest that neoadjuvant therapy with denosumab is the option for treatment of initially locally advanced tumors to facilitate complete surgical resection or avoid mutilating surgery. The risk of recurrences after curettage of GCTB following denosumab raises questions about the optimal management of such cases.

[The long-term treatment outcomes of adult osteosarcoma]

Osteosarcoma is the most common primary bone tumor. Treatment of osteosarcoma patients is based on chemotherapy as well as surgical resection of primary tumor and distant metastases. Lung metastases are the primary cause of death in this group of patients.

AIM

The aim of this study is to summarize the 20 years of osteosarcoma treatment outcomes in the Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology in Warsaw.

MATERIALS AND METHODS

Our analysis included clinical data of 299 osteosarcoma patients aged between 14 and 81 years (median 32) treated in Maria Sklodowska-Curie Memorial Cancer Center between 1998 and 2016. The standard therapeutic protocol included perioperative anthracycline-based chemotherapy and surgical resection of primary tumor and distant metastases. The statistical analysis was performed using Kaplan-Meier estimator, log-rank test and Cox proportional hazards model.

RESULTS

In analyzed group 38 (13%) patients had distant metastases at the diagnosis. The tumor size was greater than 8 cm in 61% of cases. In the histopathological assessment the most prevalent subtype was the conventional one (diagnosed in 76% of cases) and histological grade 3 (79%). The 5-year survival rate for patients with localized disease reached 46%. The negative prognostic factors included: distant metastases at diagnosis, axial location of primary tumor, unresectability of the primary lesion, higher histological grade, and older age of patients.

CONCLUSIONS

The best results of the treatment of osteosarcoma patients are achieved with multidisciplinary treatment, and when the reference center supports other healthcare providers in management of diagnostic and treatment procedures of osteosarcoma patients.

Denosumab treatment of inoperable or locally advanced giant cell tumor of bone

Giant cell tumor of bone (GCTB) is an osteolytic, locally aggressive tumor that rarely metastasizes and typically occurs in the bones. At present, the primary treatment for GCTB is curettage with local adjuvants. Giant cells express receptor activator of nuclear factor-κB ligand (RANKL). Denosumab, a RANKL inhibitor appears to present an effective therapeutic option in advanced cases of GCTB. The aim of the present study was to confirm the efficacy of denosumab in large group of patients with locally advanced GCTB. A total of 35 patients with histologically confirmed GCTB that were treated with denosumab with no participation in clinical trials between May 2013 and September 2015 were included in the present study. Denosumab treatment was administered until complete tumor resection was feasible or tumor progression or unacceptable toxicity had occurred. The mean denosumab treatment duration was 7.4 months. A total of 17 patients received surgery following denosumab treatment: 11 patients underwent wide en bloc resection with prosthesis implantation in 10 cases and 6 patients were treated with intralesional curettage. Tumor progression was observed in 2 patients that underwent intralesional curettage without prosthesis implantation. In addition, tumor progression was observed during denosumab treatment in 2 patients that had previously undergone radiotherapy. The overall 1-year progression-free survival rate was 92.8%. Thus, for patients with advanced, unresectable, progressive or symptomatic pretreated GCTB, denosumab provides a therapeutic option not previously available, which has become the standard therapy in multidisciplinary management of GCTB.

The long-term results and prognostic significance of cutaneous melanoma surgery using sentinel node biopsy with triple technique

BACKGROUND

The sentinel lymph node biopsy (SLN) is a basic staging method in all primary cutaneous melanomas ≥pT1b. The standard technique is a triple technique consisting of preoperative lymphoscintigraphy, intraoperative blue-dye lymphography, and gamma-probe assessment. We performed the analysis of long-term results in a very large one-institution series of cutaneous melanoma patients.

METHODS

We have analyzed treatment results of a group of 1764 consecutive patients with cutaneous melanoma, who underwent SLN biopsy between 1997 and 2008 in one tertiary center. Additionally, we have analyzed the outcomes of a group of 473 patients with positive SLN biopsy undergoing completion lymph node dissection (CLND). Median follow-up time was 5.3 years.

RESULTS

Metastases to SLN (SLN+) were found in 19.9%. Eight-year overall survival (OS) rate in the entire group was 73.5%, 80% without SLN metastases (SLN-) and 50% in group with SLN+ (p < 0.001). Independent prognostic factors for OS were as follows: presence of metastases to SLN, primary tumor ulceration, and higher mitotic index (>5/mm(2)) of primary tumor. The nodal recurrences in the biopsied lymphatic basin were 5.4%. The metastases to non-sentinel lymph nodes (NSLN found in 27% of patients with SLN+) correlated (on multivariable logistic regression analysis) with primary tumor thickness >4 mm, SLN metastatic deposit size >1 mm, and extracapsular involvement of SLN. In an additionally analyzed SLN+ group, the NSLN involvement was related to poorer prognosis (8-year OS rate NSLN- vs NSLN+: 59.6 vs. 34.7%, respectively). The independent prognostic factors for OS in the SLN+ group were a higher Breslow thickness and ulceration of primary tumor, metastases to more than 1 lymph nodes.

CONCLUSIONS

The long-term results confirm crucial prognostic significance of SLN biopsy in cutaneous melanoma. We identified factors related to NSLN involvement, which in the future may limit indications for CLND.

Preoperative hypofractionated radiotherapy in the treatment of localized soft tissue sarcomas

BACKGROUND

The primary treatment of soft tissue sarcomas (STS) is a radical resection of the tumor with adjuvant radiotherapy. Conventional fractionation of preoperative radiotherapy is 50 Gy in fraction of 2 Gy a day. The purpose of the conducted study was to assess the efficacy and safety of hypofractionated radiotherapy in preoperative setting in STS patients.

METHODS

272 patients participated in this prospective study conducted from 2006 till 2011. Tumors were localized on the extremities or trunk wall. Median tumor size was 8.5 cm, 42% of the patients had tumor larger than 10 cm, whereas 170 patients (64.6%) had high grade (G3) tumors. 167 patients (61.4%) had primary tumors. Patients were treated with preoperative radiotherapy for five consecutive days in 5 Gy per fraction, with an immediate surgery. Median follow up is 35 months.

RESULTS

79 patients died at the time of the analysis, the 3-year overall survival was 72%. Local recurrences were observed in 19.1 % of the patients. Factors that had a significant adverse impact on local recurrence were tumor size of 10 cm or more and G3 grade. 114 patients (42%) had any kind of treatment toxicity, vast majority with tumors located on lower limbs. 7% (21) of the patients required surgery for treatment of the complications.

CONCLUSION

In this non-selected group of locally advanced STS use of hypofractionated preoperative radiotherapy was associated with similar local control (81%) when compared to previously published studies. The early toxicity is tolerable, with small rate of late complications. Presented results warrant further evaluation.