Intensified Chemotherapy With Dexrazoxane Cardioprotection in Newly Diagnosed Nonmetastatic Osteosarcoma: A Report From the Children's Oncology Group

BACKGROUND

Although chemotherapy has improved outcome of osteosarcoma, 30-40% of patients succumb to this disease. Survivors experience substantial morbidity and mortality from anthracycline-induced cardiotoxicity. We hypothesized that the cardioprotectant dexrazoxane would (i) support escalation of the cumulative doxorubicin dose (600 mg/m(2)) and (ii) not interfere with the cytotoxicity of chemotherapy measured by necrosis grading in comparison to historical control data.

PROCEDURE

Children and adolescents with nonmetastatic osteosarcoma were treated with MAP (methotrexate, doxorubicin, cisplatin) or MAPI (MAP/ifosfamide). Dexrazoxane was administered with all doxorubicin doses. Cardioprotection was assessed by measuring left ventricular fractional shortening. Interference with chemotherapy-induced cytotoxicity was determined by measuring tumor necrosis after induction chemotherapy. Feasibility of intensifying therapy with either high cumulative-dose doxorubicin or high-dose ifosfamide/etoposide was evaluated for "standard responders" (SR, <98% tumor necrosis at definitive surgery).

RESULTS

Dexrazoxane did not compromise response to induction chemotherapy. With doxorubicin (450-600 mg/m(2)) and dexrazoxane, grade 1 or 2 left ventricular dysfunction occurred in five patients; 4/5 had transient effects. Left ventricular fractional shortening z-scores (FSZ) showed minimal reductions (0.0170  ±  0.009/week) over 78 weeks. Two patients (<1%) had secondary leukemia, one as a first event, a similar rate to what has been observed in prior trials. Intensification with high-dose ifosfamide/etoposide was also feasible.

CONCLUSIONS

Dexrazoxane cardioprotection was safely administered. It did not impair tumor response or increase the risk of secondary malignancy. Dexrazoxane allowed for therapeutic intensification increasing the cumulative doxorubicin dose in SR to induction chemotherapy. These findings support the use of dexrazoxane in children and adolescents with osteosarcoma.

Prosthetic-Joint-Associated Bordetella holmesii Infection

Bordetella holmesii is a globally distributed pathogen that is increasingly recognized as a cause of both pertussis-like respiratory infections and invasive disease. In this study, we describe a case of an immunocompetent man who developed B holmesii infection of his femoral prosthesis—the fifth B holmesii orthopedic infection reported in literature to date. This article highlights the potentially underrecognized role of B holmesii in orthopedic infections by reviewing these previously reported cases in the context of the current literature.

Conservative surgery in the treatment of giant cell tumor of the sacrum: 35 years' experience

OBJECT There is no consensus regarding the appropriate treatment of sacral giant cell tumor (GCT). There are 3 main management problems: tumor control, neurological loss, and pelvic instability. The objective of this study was to examine oncological, neurological, and structural outcomes of sacral GCT after intralesional excision and local intraoperative adjunctive treatment. METHODS The authors retrospectively reviewed the records of 24 patients with sacral GCT who underwent conservative surgery (intralesional resection/curettage) at Memorial Sloan Kettering Cancer Center from 1973 through 2012. They analyzed patient demographic data, tumor characteristics, and operative techniques, and examined possible correlations with postoperative functional outcomes, complications, recurrence, and mortality. RESULTS There were 7 local recurrences (30%) and 3 distant recurrences (13%). Three of 24 patients (12.5%) had significant neurological loss after treatment-specifically, severe bowel and/or bladder dysfunction, but all regained function within 1-4 years. Larger tumor size (> 320 cm³) was associated with greater postoperative neurological loss. Radiation therapy and preoperative embolization were associated with prolonged disease-free survival. There were no local recurrences among the 11 patients who were treated with both modalities. Based on radiographic and clinical assessment, spinopelvic stability was present in 23 of 24 patients at final follow-up. CONCLUSIONS High local and distant recurrence rates associated with sacral GCT suggest the need for careful local and systemic follow-up in managing these patients. Intraoperative preservation of sacral roots was associated with better pain relief, improvement in ambulatory function, and retention of bowel/bladder function in most patients. Fusion and instrumentation of the sacroiliac joint successfully achieved spinopelvic stability in cases deemed clinically unstable. Despite improvement in the management of sacral GCT over 35 years, a need for novel therapies remains. The strategy of combining radiotherapy and embolization merits further study.

Tumour exosome integrins determine organotropic metastasis

Ever since Stephen Paget's 1889 hypothesis, metastatic organotropism has remained one of cancer's greatest mysteries. Here we demonstrate that exosomes from mouse and human lung-, liver- and brain-tropic tumour cells fuse preferentially with resident cells at their predicted destination, namely lung fibroblasts and epithelial cells, liver Kupffer cells and brain endothelial cells. We show that tumour-derived exosomes uptaken by organ-specific cells prepare the pre-metastatic niche. Treatment with exosomes from lung-tropic models redirected the metastasis of bone-tropic tumour cells. Exosome proteomics revealed distinct integrin expression patterns, in which the exosomal integrins α6β4 and α6β1 were associated with lung metastasis, while exosomal integrin αvβ5 was linked to liver metastasis. Targeting the integrins α6β4 and αvβ5 decreased exosome uptake, as well as lung and liver metastasis, respectively. We demonstrate that exosome integrin uptake by resident cells activates Src phosphorylation and pro-inflammatory S100 gene expression. Finally, our clinical data indicate that exosomal integrins could be used to predict organ-specific metastasis.

Tumour exosome integrins determine organotropic metastasis

Ever since Stephen Paget’s 1889 hypothesis, metastatic organotropism has remained one of cancer’s greatest mysteries. Here we demonstrate that exosomes from mouse and human lung-, liver- and brain-tropic tumour cells fuse preferentially with resident cells at their predicted destination, namely lung fibroblasts and epithelial cells, liver Kupffer cells and brain endothelial cells. We show that tumour-derived exosomes uptaken by organ-specific cells prepare the pre-metastatic niche. Treatment with exosomes from lung-tropic models redirected the metastasis of bone-tropic tumour cells. Exosome proteomics revealed distinct integrin expression patterns, in which the exosomal integrins α₆β₄ and α₆β₁ were associated with lung metastasis, while exosomal integrin α_vβ₅ was linked to liver metastasis. Targeting the integrins α₆β₄ and α_vβ₅ decreased exosome uptake, as well as lung and liver metastasis, respectively. We demonstrate that exosome integrin uptake by resident cells activates Src phosphorylation and pro-inflammatory S100 gene expression. Finally, our clinical data indicate that exosomal integrins could be used to predict organ-specific metastasis.

A Phase Ib/II Study of Gemcitabine and Docetaxel in Combination With Pazopanib for the Neoadjuvant Treatment of Soft Tissue Sarcomas

LESSONS LEARNED

Our results highlight some of the challenges in the management of soft tissue sarcomas, which requires close cooperation between surgeons and medical oncologists and a careful selection of patients. The incidence of hepatotoxicity was a concerning finding and had been previously reported in patients treated with pazopanib.Although pharmacokinetic analysis was not part of this study, concomitant treatment with pazopanib has been recently reported to increase docetaxel exposure, which may explain the increased toxicity of combination regimens. It remains possible that lower doses of combined gemcitabine, docetaxel, and pazopanib may be tolerable. However, caution should be exercised in future trials investigating similar combinations.

BACKGROUND

For extremity soft tissue sarcomas (STS), surgical resection remains the standard of care, and the addition of chemotherapy is controversial. This was a phase Ib/II trial of neoadjuvant therapy for patients with STS.

METHODS

Patients with high grade, extremity STS of >8 cm and amenable to definitive resection were treated with up to four 21-day cycles of 900 mg/m(2) gemcitabine on days 1 and 8, 75 mg/m(2) docetaxel on day 8, and 400 mg of pazopanib daily (GDP), followed by surgery and, if indicated, radiation therapy. Primary and secondary endpoints (phase Ib portion) were the safety and rate of pathologic response.

RESULTS

The trial was discontinued because of slow accrual after inclusion of five patients (leiomyosarcoma: two; undifferentiated pleomorphic sarcoma: three). Two patients completed four treatment cycles: one underwent surgery and one had insufficient response and received additional therapies. Three patients discontinued treatment because of toxicity. Grade 3 adverse events included hypertension, fatigue, aspartate aminotransferase (AST) or alanine aminotransferase (ALT) elevation, hoarseness, and myelotoxicity. There were no complete or partial responses. One patient had ≥ 90% pathologic response. Among four patients who underwent resection, three remain free of disease, and one patient eventually relapsed.

CONCLUSION

GDP combination used in the neoadjuvant setting resulted in significant toxicity; despite pathologic responses, no objective responses occurred.

Structure-Guided Blockade of CSF1R Kinase in Tenosynovial Giant-Cell Tumor

BACKGROUND

Expression of the colony-stimulating factor 1 (CSF1) gene is elevated in most tenosynovial giant-cell tumors. This observation has led to the discovery and clinical development of therapy targeting the CSF1 receptor (CSF1R).

METHODS

Using x-ray co-crystallography to guide our drug-discovery research, we generated a potent, selective CSF1R inhibitor, PLX3397, that traps the kinase in the autoinhibited conformation. We then conducted a multicenter, phase 1 trial in two parts to analyze this compound. In the first part, we evaluated escalations in the dose of PLX3397 that was administered orally in patients with solid tumors (dose-escalation study). In the second part, we evaluated PLX3397 at the chosen phase 2 dose in an extension cohort of patients with tenosynovial giant-cell tumors (extension study). Pharmacokinetic and tumor responses in the enrolled patients were assessed, and CSF1 in situ hybridization was performed to confirm the mechanism of action of PLX3397 and that the pattern of CSF1 expression was consistent with the pathological features of tenosynovial giant-cell tumor.

RESULTS

A total of 41 patients were enrolled in the dose-escalation study, and an additional 23 patients were enrolled in the extension study. The chosen phase 2 dose of PLX3397 was 1000 mg per day. In the extension study, 12 patients with tenosynovial giant-cell tumors had a partial response and 7 patients had stable disease. Responses usually occurred within the first 4 months of treatment, and the median duration of response exceeded 8 months. The most common adverse events included fatigue, change in hair color, nausea, dysgeusia, and periorbital edema; adverse events rarely led to discontinuation of treatment.

CONCLUSIONS

Treatment of tenosynovial giant-cell tumors with PLX3397 resulted in a prolonged regression in tumor volume in most patients. (Funded by Plexxikon; ClinicalTrials.gov number, NCT01004861.).

How do we estimate survival? External validation of a tool for survival estimation in patients with metastatic bone disease-decision analysis and comparison of three international patient populations

Background

We recently developed a clinical decision support tool, capable of estimating the likelihood of survival at 3 and 12 months following surgery for patients with operable skeletal metastases. After making it publicly available on www.PATHFx.org, we attempted to externally validate it using independent, international data.

Methods

We collected data from patients treated at 13 Italian orthopaedic oncology referral centers between 2010 and 2013, then applied to PATHFx, which generated a probability of survival at three and 12-months for each patient. We assessed accuracy using the area under the receiver-operating characteristic curve (AUC), clinical utility using Decision Curve Analysis (DCA), and compared the Italian patient data to the training set (United States) and first external validation set (Scandinavia).

Results

The Italian dataset contained 287 records with at least 12 months follow-up information. The AUCs for the three-month and 12-month estimates was 0.80 and 0.77, respectively. There were missing data, including the surgeon’s estimate of survival that was missing in the majority of records. Physiologically, Italian patients were similar to patients in the training and first validation sets. However notable differences were observed in the proportion of those surviving three and 12-months, suggesting differences in referral patterns and perhaps indications for surgery.

Conclusions

PATHFx was successfully validated in an Italian dataset containing missing data. This study demonstrates its broad applicability to European patients, even in centers with differing treatment philosophies from those previously studied.

Ewing sarcoma in adults treated with modern radiotherapy techniques

BACKGROUND AND PURPOSE

To evaluate local control and survival outcomes in adults with Ewing sarcoma (ES) treated with radiotherapy (RT).

MATERIAL AND METHODS

Retrospective review of all 109 patients age ⩾18 treated for ES with RT to the primary site at Memorial Sloan Kettering Cancer Center between 1990 and 2011. RT was used as the definitive local control modality in 44% of patients, preoperatively for 6%, and postoperatively for 50%.

RESULTS

Median age at diagnosis was 27years (range, 18-67). The 5-year local failure (LF) was 18%. Differences in LF were not identified when evaluated by modality of local control (RT versus combined surgery and RT), RT dose, fractionation, and RT technique. However, margin status at time of resection significantly predicted LF. The 5-year event-free survival and overall survival rates were 44% and 66% for patients with localized disease, compared with 16% and 26% for metastatic disease (p=0.0005 and 0.0002). Tumor size, histopathologic response to chemotherapy, and treatment on or according to a protocol were also significantly associated with survival.

CONCLUSIONS

This series of adults treated with modern chemotherapy and RT had prognostic factors and outcomes similar to adolescents with ES. All adults with ES should be treated with an aggressive, multidisciplinary approach.

Embolization of hypervascular bone metastases reduces intraoperative blood loss: a case-control study

BACKGROUND

Small case series suggest that preoperative transcatheter arterial embolization minimizes bleeding and facilitates surgery for hypervascular metastatic bone tumors. However, control groups would make our confidence in clinical recommendations stronger, but small patient numbers make prospective trials difficult to conduct on this topic.

QUESTIONS/PURPOSES

In this case-control study, we asked whether (1) patients who undergo embolization have less estimated blood loss and/or shorter operative time than patients who do not have embolization; (2) larger tumor size, greater initial tumor vascularity, and longer interval from embolization to surgery are associated with greater estimated blood loss and packed red blood cell transfusion volume; and (3) embolization does not affect renal function in patients with normal preoperative renal function.

METHODS

We retrospectively reviewed records of patients with hypervascular bone metastases treated at our institution between 1998 and 2008. Twenty-seven patients with renal cell carcinoma and 12 with thyroid carcinoma who underwent embolization before 41 surgical procedures were matched to 41 patients who did not have embolization with respect to age, diagnosis, tumor size and potential vascularity, and procedure type; matching was performed without knowledge of outcomes. In univariate and multivariate analyses, age, tumor size, use of embolization, surgery type and risk, embolization-to-surgery interval, and degree of devascularization were evaluated for correlations with estimated blood loss, packed red blood cell transfusion volume, operative time, and postembolization renal function.

RESULTS

Overall, patients who had embolization had less mean estimated blood loss (0.90 versus 1.77 L; p = 0.002), packed red blood cell transfusion volume (2.15 versus 3.56 U; p = 0.020), and operative time (3.13 versus 3.91 hours; p < 0.001). Larger tumor size correlated with greater estimated blood loss (r = 0.451; p = 0.003), packed red blood cell transfusion volume (r = 0.50; p = 0.002), and operative time (r = 0.595; p < 0.001). Neither the interval for embolization to surgery nor the degree of devascularization correlated with estimated blood loss or transfusion volume. In open rodding with intralesional curettage, transcatheter arterial embolization was associated with reduced estimated blood loss, transfusion volume, and operative time. Packed red blood cell transfusion volume was not reduced by embolization in intramedullary nailing procedures with the patient numbers available. Among patients with normal preoperative renal function who had embolization, creatinine levels remained normal. Mild transient, reversible renal function change occurred in one patient with preoperatively abnormal renal function.

CONCLUSIONS

This study suggests that preoperative embolization probably reduces estimated blood loss, particularly for large tumors and during open femoral procedures.

Comparative evaluation of local control strategies in localized Ewing sarcoma of bone: a report from the Children's Oncology Group

BACKGROUND

Patients with Ewing sarcoma require local primary tumor control with surgery, radiation, or both. The optimal choice of local control for overall and local disease control remains unclear.

METHODS

Patients with localized Ewing sarcoma of bone who were treated on 3 consecutive protocols with standard-dose, 5-drug chemotherapy every 3 weeks were included (n=465). Propensity scores were used to control for differences between local control groups by constructing multivariate models to assess the impact of local control type on clinical endpoints (event-free survival [EFS], overall survival, local failure, and distant failure) independent of differences in their propensity to receive each local control type.

RESULTS

Patients who underwent surgery were younger (P=.02) and had more appendicular tumors (P<.001). Compared with surgery, radiation had higher unadjusted risks of any event (hazard ratio [HR], 1.70; 95% confidence interval [CI], 1.18-2.44), death (HR, 1.84; 95% CI, 1.18-2.85), and local failure (HR, 2.57; 95% CI, 1.37-4.83). On multivariate analysis, compared with surgery, radiation had a higher risk of local failure (HR, 2.41; 95% CI, 1.24-4.68), although there were no significant differences in EFS (HR, 1.42; 95% CI, 0.94-2.14), overall survival (HR, 1.37; 95% CI, 0.83-2.26), or distant failure (HR, 1.13; 95% CI, 0.70-1.84) between local control groups.

CONCLUSIONS

In this large group of similarly treated patients, choice of the mode of local control was not related significantly to EFS, overall survival, or distant failure, although the risk of local failure was greater for radiation compared with surgery. These data support surgical resection when appropriate, whereas radiotherapy remains a reasonable alternative in selected patients.

EWSR1-PBX3: a novel gene fusion in myoepithelial tumors

The genetics of myoepithelial tumors (ME) of soft tissue and bone have recently been investigated, with EWSR1-related gene fusions being seen in approximately half of the tumors. The fusion partners of EWSR1 so far described include POU5F1, PBX1, ZNF444 and, in a rare case, ATF1. We investigated by RNA sequencing an index case of EWSR1-rearranged ME of the tibia, lacking a known fusion partner, and identified a novel EWSR1-PBX3 fusion. The fusion was further validated by reverse transcriptase polymerase chain reaction and fluorescence in situ hybridization (FISH). To evaluate if this is a recurrent event, an additional cohort of 22 EWSR1-rearranged ME cases lacking a fusion partner were screened by FISH for abnormalities in PBX3 gene. Thus, two additional cases were identified showing an EWSR1-PBX3 gene fusion. One of them was also intraosseous involving the ankle, while the other occurred in the soft tissue of the index finger. The morphology of the EWSR1-PBX3 fusion positive cases showed similar findings, with nests or sheets of epithelioid to spindle cells in a partially myxoid to collagenous matrix. All three cases showed expression of S100 and EMA by immunohistochemistry. In summary, we report a novel EWSR1-PBX3 gene fusion in a small subset of ME, thereby expanding the spectrum of EWSR1-related gene fusions seen in these tumors. This gene fusion seems to occur preferentially in skeletal ME, with two of the three study cases occurring in intraosseous locations.

Analysis of outcomes in extraskeletal osteosarcoma: a review of fifty-three cases

BACKGROUND

Extraskeletal osteosarcoma is a rare soft-tissue sarcoma about which little is known. The objectives of this study were to describe the clinical features and natural history of extraskeletal osteosarcoma and to investigate factors affecting outcomes.

METHODS

A retrospective review of a prospectively maintained database of patients diagnosed with soft-tissue sarcoma was conducted. Patients with pathologically confirmed extraskeletal osteosarcoma from 1982 to 2012 were identified and were included in the analysis. Medical records were reviewed for clinical features, treatment, and outcomes.

RESULTS

Fifty-three patients were identified from the database: forty-two presented with localized disease, two presented with metastatic disease, and nine presented with recurrent (local and/or distant) disease. The median patient age at diagnosis was sixty-four years, with a median follow-up time of thirty-four months (range, one to 290 months) for survivors. Of the fifty-three patients who were identified, forty-one had lesions in the extremities, fifty-one had high-grade lesions, forty had lesions >5 cm, and forty-two had deep lesions. For patients presenting with localized disease, the median survival was 45.8 months with a three-year cumulative incidence of death due to disease of 39%. All patients with localized disease were managed with surgical resection of the primary tumor: nineteen with surgery only, ten with adjuvant radiation, five with adjuvant chemotherapy, and eight with both radiation and chemotherapy. Eighteen patients relapsed: two patients had local recurrences, ten patients had distant metastases, and six patients had local recurrences and distant metastases. In log-rank analysis, patients with superficial tumors and negative margins at resection had a higher three-year event-free survival. No significant association of disease-specific or event-free survival was found with the addition of radiation, chemotherapy, or both to surgery.

CONCLUSIONS

For patients presenting with localized extraskeletal osteosarcoma, three-year event-free survival was higher for patients with superficial tumors and negative margins at resection. Radiation and chemotherapeutic treatment were not associated with a lower incidence of death due to disease or a longer event-free survival.

Induction of sarcomas by mutant IDH2

More than 50% of patients with chondrosarcomas exhibit gain-of-function mutations in either isocitrate dehydrogenase 1 (IDH1) or IDH2. In this study, we performed genome-wide CpG methylation sequencing of chondrosarcoma biopsies and found that IDH mutations were associated with DNA hypermethylation at CpG islands but not other genomic regions. Regions of CpG island hypermethylation were enriched for genes implicated in stem cell maintenance/differentiation and lineage specification. In murine 10T1/2 mesenchymal progenitor cells, expression of mutant IDH2 led to DNA hypermethylation and an impairment in differentiation that could be reversed by treatment with DNA-hypomethylating agents. Introduction of mutant IDH2 also induced loss of contact inhibition and generated undifferentiated sarcomas in vivo. The oncogenic potential of mutant IDH2 correlated with the ability to produce 2-hydroxyglutarate. Together, these data demonstrate that neomorphic IDH2 mutations can be oncogenic in mesenchymal cells.

Quality of life following amputation or limb preservation in patients with lower extremity bone sarcoma

Purpose: Although functional differences have been described between patients with lower extremity bone sarcoma with amputation and limb-preservation surgery, differences have not clearly been shown between the two groups related to quality of life. The purpose of the study was to determine if there is a difference in overall quality of life in lower extremity bone sarcoma survivors related to whether they had an amputation or a limb-preservation procedure while identifying psychological differences for further evaluation. The main hypothesis was that sparing a person’s limb, as opposed to amputating it, would result in a better quality of life.

Patients and Methods: Eighty-two long-term survivors of lower extremity bone sarcoma were studied to make a comparison of the overall quality of life, pain assessment, and psychological evaluations in limb preservation and amputation patients. Forty-eight patients with limb preservation and thirty-four patients with amputations were enrolled in the study. Validated psychometric measures including the Quality of Life Questionnaire (QLQ), the Minnesota Multiphasic Personality Inventory, and visual analog scales were utilized.

Results: The overall quality of life of patients with limb preservation was significantly higher than patients with amputation (p-value < 0.01). Significant differences were noted in the categories of material well-being, job satisfiers, and occupational relations.

Conclusion: The overall quality of life of patients with limb-preservation appears to be better than for those patients with amputation based on the QLQ in patients surviving lower extremity bone sarcoma. Further analysis needs to verify the results and focus on the categories that significantly affect the overall quality of life.

Additive Influence of Extracellular pH, Oxygen Tension, and Pressure on Invasiveness and Survival of Human Osteosarcoma Cells

BACKGROUND/PURPOSE

The effects of chemical and physical interactions in the microenvironment of solid tumors have not been fully elucidated. We hypothesized that acidosis, hypoxia, and elevated interstitial fluid pressure (eIFP) have additive effects on tumor cell biology and lead to more aggressive behavior during tumor progression. We investigated this phenomenon using three human osteosarcoma (OS) cell lines and a novel in vitro cell culture apparatus.

MATERIALS AND METHODS

U2OS, SaOS, and MG63 cell lines were cultured in media adjusted to various pH levels, oxygen tension (hypoxia 2% O2, normoxia 20% O2), and hydrostatic gage pressure (0 or 50 mmHg). Growth rate, apoptosis, cell cycle parameters, and expression of mRNA for proteins associated with invasiveness and tumor microenvironment (CA IX, VEGF-A, HIF-1A, MMP-9, and TIMP-2) were analyzed. Levels of CA IX, HIF-1α, and MMP-9 were measured using immunofluorescence. The effect of pH on invasiveness was evaluated in a Matrigel chamber assay.

RESULTS

Within the acidic-hypoxic-pressurized conditions that simulate the microenvironment at a tumor's center, invasive genes were upregulated, but the cell cycle was downregulated. The combined influence of acidosis, hypoxia, and IFP promoted invasiveness and angiogenesis to a greater extent than did pH, pO2, or eIFP individually. Significant cell death after brief exposure to acidic conditions occurred in each cell line during acclimation to acidic media, while prolonged exposure to acidic media resulted in reduced cell death. Furthermore, 48-h exposure to acidic conditions promoted tumor invasiveness in the Matrigel assay.

CONCLUSION

Our findings demonstrate that tumor microenvironmental parameters - particularly pH, pO2, and eIFP - additively influence tumor proliferation, invasion, metabolism, and viability to enhance cell survival and must be controlled in OS research.

Targeting the giant cell tumor stromal cell: functional characterization and a novel therapeutic strategy

Giant cell tumor of bone (GCTB) is a benign, locally destructive neoplasm, with tumors comprised of mesenchymal fibroblast-like stromal cells; monocytic, mononuclear cells of myeloid lineage; and the characteristic osteoclast-like, multinucleated giant cells. Hampering the study of the complex interaction of its constituent cell types is the propensity of longstanding, repeatedly passaged cell cultures to undergo phenotypic alteration and loss of osteoclast-inducing capacities. In this study, we employed a novel, single-step technique to purify freshly harvested stromal cells using a CD14-negative selection column. Using 9 freshly harvested GCTB specimens and the purified stromal cell component, we performed analyses for markers of osteoblast lineage and analyzed the capacity of the stromal cells to undergo osteoblastic differentiation and induce osteoclastogenesis in co-cultures with monocytic cells. Successful purification of the CD14-negative stromal cells was confirmed via flow cytometric analysis and immunocytochemistry. Osteogenic media upregulated the expression of osteocalcin, suggesting an osteoblastic lineage of the GCTB stromal cells. The effects of the Wnt pathway agonist, SB415286, and recombinant human bone morphogenetic protein (BMP)-2 on osteoblastogenesis varied among samples. Notably, osteogenic media and SB415286 reversed the receptor activator of NF-κB ligand (RANKL)/osteoprotegerin (OPG) expression ratio resulting in diminished osteoclastogenic capacity. Recombinant human BMP2 had the opposite effect, resulting in enhanced and sustained support of osteoclastogenesis. Targeting the giant cell tumor stromal cell may be an effective adjunct to existing anti-resorptive strategies.

Trends in the surgical treatment of pathologic proximal femur fractures among Musculoskeletal Tumor Society members

BACKGROUND

Several strategies for the treatment of pathologic proximal femur fractures are practiced but treatment outcomes have not been rigorously compared.

QUESTIONS/PURPOSES

Major variations in the use of intramedullary fixation, extramedullary/plate-screw fixation, and endoprosthetic reconstruction techniques for pathologic proximal femur fractures in patients with skeletal metastases are reported. The clinical and surgical variables that influence this choice differ among treating surgeons. To characterize the technique preferences and to identify areas of consensus regarding specific clinical presentations, we administered an online survey to the Musculoskeletal Tumor Society (MSTS) membership. We also tested whether responses correlated with the respondents' years in practice and asked about the indications for wide tumor resection and the role of tumor debulking and adjuvant cementation.

METHODS

A 10-minute, web-based survey was sent via email to 244 MSTS members. The survey queried participants' musculoskeletal oncology training and experience and presented case scenarios illustrating different combinations of four variables that influence decision-making: cancer type, estimated patient survival, fracture displacement, and anatomic region of involvement.

RESULTS

Forty-one percent (n = 98) of MSTS members completed the survey. Intramedullary nail fixation (IMN; 45%) and proximal femur resection and reconstruction (34%) were the most commonly recommended techniques followed by long-stem cemented hemiarthroplasty/cemented hemiarthroplasty (15%) and open reduction and internal fixation (7%). Most respondents (56%) recommended use of cementation with IMN. Differences of opinion on recommended treatment were associated with variations in cancer type, fracture displacement, and anatomic region of involvement.

CONCLUSIONS

Our online survey showed a trend among MSTS members for selecting IMN and arthroplasty-related techniques to treat pathologic fractures of the proximal femur, but major differences in preferred operative technique exist. Prospective studies are needed to develop consistent, evidence-based treatment recommendations.

Making a case for the socioeconomic determinacy of survival in osteosarcoma

BACKGROUND

The literature on osteosarcoma survival generally focuses on tumor and treatment variables, although it is unclear whether and how ethnic and socioeconomic factors might influence survival.

QUESTIONS/PURPOSES

We therefore investigated the relative contribution of socioeconomic influences together with more traditional tumor-specific factors on osteosarcoma survival.

METHODS

We performed survival analyses on two national databases in two countries. Using multivariable analyses, we compared these with corresponding institution-specific survival to determine if socioeconomic factors might impact osteosarcoma survival.

RESULTS

East Asian descent, state-specific treatment, female sex, treatment in the 1990s, low-grade disease, intracompartmental disease, small size, wide resections as opposed to forequarter or hindquarter amputations, and single primaries were good prognostic factors. Survival was better in the more affluent states. Males were affected at an older age than females. Blacks tended to have larger tumors, although their overall survival was similar to whites. East Asians were more likely to be treated in the 1990s with wide resections for smaller tumors and were located around states associated with good treatment. East Asians in Singapore and the United States had the same survival. Survival in East Asians in Singapore was similar to that of other races. The provision of health care for osteosarcoma varies greatly across the United States but is uniform in the socialized medical system in Singapore. Hence, the observed differences in the United States were likely the result of socioeconomic factors.

CONCLUSIONS

Our analysis suggests ethnic and economic bias may influence survival in osteosarcoma and should receive greater attention in the collective literature on survival analyses.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

External validation of the Bayesian Estimated Tools for Survival (BETS) models in patients with surgically treated skeletal metastases

Background

We recently developed two Bayesian networks, referred to as the Bayesian-Estimated Tools for Survival (BETS) models, capable of estimating the likelihood of survival at 3 and 12 months following surgery for patients with operable skeletal metastases (BETS-3 and BETS-12, respectively). In this study, we attempted to externally validate the BETS-3 and BETS-12 models using an independent, international dataset.

Methods

Data were collected from the Scandinavian Skeletal Metastasis Registry for patients with extremity skeletal metastases surgically treated at eight major Scandinavian referral centers between 1999 and 2009. These data were applied to the BETS-3 and BETS-12 models, which generated a probability of survival at 3 and 12 months for each patient. Model robustness was assessed using the area under the receiver-operating characteristic curve (AUC). An analysis of incorrect estimations was also performed.

Results

Our dataset contained 815 records with adequate follow-up information to establish survival at 12 months. All records were missing data including the surgeon’s estimate of survival, which was previously shown to be a first-degree associate of survival in both models. The AUCs for the BETS-3 and BETS-12 models were 0.79 and 0.76, respectively. Incorrect estimations by both models were more commonly optimistic than pessimistic.

Conclusions

The BETS-3 and BETS-12 models were successfully validated using an independent dataset containing missing data. These models are the first validated tools for accurately estimating postoperative survival in patients with operable skeletal metastases of the extremities and can provide the surgeon with valuable information to support clinical decisions in this patient population.

Randomized controlled trial of interval-compressed chemotherapy for the treatment of localized Ewing sarcoma: a report from the Children's Oncology Group

PURPOSE

Chemotherapy with alternating vincristine-doxorubicin-cyclophosphamide and ifosfamide-etoposide cycles and primary tumor treatment with surgery and/or radiation therapy constitute the usual approach to localized Ewing sarcoma in North America. We tested whether chemotherapy intensification through interval compression could improve outcome.

PATIENTS AND METHODS

This was a prospective, randomized controlled trial for patients younger than 50 years old with newly diagnosed localized extradural Ewing sarcoma. Patients assigned to standard and intensified treatment were to begin chemotherapy cycles every 21 and 14 days, respectively, provided an absolute neutrophil count greater than 750×10(6)/L and a platelet count greater than 75×10(9)/L. Patients received vincristine (2 mg/m2), doxorubicin (75 mg/m2), and cyclophosphamide (1.2 g/m2) alternating with ifosfamide (9 g/m2) and etoposide (500 mg/m2) for 14 cycles, with filgrastim (5 mg/kg per day; maximum, 300 mg) between cycles. Primary tumor treatment (surgery, radiation, or both) was to begin at week 13 (after four cycles in the standard arm and six cycles in the intensified arm). The primary end point was event-free survival (EFS). The study is registered at ClinicalTrials.gov (identifier: NCT00006734).

RESULTS

Five hundred eighty-seven patients were enrolled and randomly assigned, and 568 patients were eligible, with 284 patients in each regimen. For all cycles, the median cycle interval for standard treatment was 21 days (mean, 22.45 days); for intensified treatment, the median interval was 15 days (mean, 17.29 days). EFS at a median of 5 years was 65% in the standard arm and 73% in the intensified arm (P=.048). The toxicity of the regimens was similar.

CONCLUSION

For localized Ewing sarcoma, chemotherapy administered every 2 weeks is more effective than chemotherapy administered every 3 weeks, with no increase in toxicity.