Treatment pathway of bone sarcoma in children, adolescents, and young adults

Extent of physician-pharmaceutical industry interactions in low- and middle-income countries: a systematic review

Background

Pharmaceutical companies spend large amounts of money promoting their products to physicians. There is evidence that physicians' interactions with pharmaceutical companies negatively affect their prescribing patterns. The objective of this study was to systematically review the extent of the relationship between physicians and pharmaceutical companies in low- and middle-income countries (LMICs).

Methods

Studies assessing the extent of any type of interaction between practicing physicians and pharmaceutical companies were eligible. We searched MEDLINE and EMBASE databases in July 2016. Reviewers worked in duplicate and independently to complete study selection, data abstraction and assessment of methodological features. We summarized the findings narratively.

Results

We included 11 eligible studies (7 quantitative and 4 qualitative). Quantitative studies found that pharmaceutical company representatives visited at least 90% of physicians. Printed material, stationery items and drug samples were the most frequently received gifts. Two of the studies assessing direct payment found percentages of 16 and 5%, respectively. Findings of qualitative studies were consistent with those of quantitative studies. In addition, they revealed an increasing tendency for pharmaceutical companies to provide expensive personal gifts, sponsor social events and offer cash as inducements to physicians based on their demands. They also identified building personal relationships, creating a sense of indebtedness and emotional blackmailing as commonly used techniques to influence physicians.

Conclusion

A relatively high percentage of physicians in LMICs interact with pharmaceutical companies. Findings have implications for policy and practice, given the current extent of interaction is likely affecting the prescribing habits and professional behaviour of physicians.

SCMCIE94: an intensified pilot treatment protocol known to be associated with cure in CD 56-negative non-pelvic isolated Ewing sarcoma (EWS) is also associated with no early relapses in non-metastatic extremity EWS

PURPOSE

We report the unexpected absence of early relapse (before 30 months) in 24 consecutive patients with isolated limb primary Ewing sarcoma treated with an intensified pilot protocol, SCMCIE94.

METHODS

Clinical data for the study were collected retrospectively from the patient files. The protocol included 6 courses of chemotherapy, split radiation, and limb salvage surgery. This SCMCIE94 protocol had been used in almost all the patients described in an earlier report, in whom those with non-pelvic isolated tumors and low/absent CD56 expression in Ewing sarcoma tumor cells were all long-term survivors.

RESULTS

The 5-year (10-year) event-free survival rate for the patients with isolated limb primary Ewing sarcoma was 78.95 ± 8.3% (68.6 ± 10.0%) and the overall survival rate was 90.7 ± 6.2% (71.1 ± 11.2%). There were no relapses before 30 months in any of these patients.

CONCLUSION

The intensified SCMCIE94 pilot protocol has been shown previously to cure patients with localized CD56-negative non-pelvic Ewing sarcoma. The present study shows that among all patients with localized extremity disease who were treated with this protocol, there were no cases of early relapse. Although our cohort was small, the difference in results from studies using other protocols is so striking, that it would seem reasonable to assume it is attributable to the changes made in the protocol itself rather than risk factors. Late relapses of isolated limb CD56-positive Ewing sarcoma suggest minimal residual disease warranting additional therapeutic approaches such as autologous stem cell rescue after Busulfan Melfelan.

Treatment and survival of osteosarcoma and Ewing sarcoma of the skull: a SEER database analysis

Background

Common primary bone tumors include osteosarcomas (OSC) and Ewing sarcomas (EWS). The skull is a rare site, and literature about their treatment and survival is scarce. Using the Surveillance, Epidemiology, and End Results (SEER) database, this study aims to assess the treatment and survival of skull OSC and skull EWS, as well as predictors for survival.

Methods

Skull OSC and EWS cases were obtained from the SEER database. Patient and tumor characteristics, treatment modalities, and survival were extracted. Overall survival (OS) was assessed using multivariable Cox proportional hazard regression stratified by tumor histology. Kaplan-Meier curves were constructed for OS comparing OSC and EWS, as well as histological subtypes in OSC.

Results

A total of 321 skull OSC and 80 skull EWS patients were registered from 1973 to 2013. EWS was more common in younger patients (p < 0.001). Resection was the predominant treatment strategy (80.1%), frequently in combination with adjuvant radiotherapy (30.4%). The 5-year survival rate varied significantly between OSC and EWS (51.0% versus 68.5%, p = 0.02). Kaplan-Meier curves show that EWS had a significantly better survival compared to OSC. Comparing histological subtypes of skull OSC, chondroblastic OSC had the best OS, Paget OSC the worst. Older age, tumor advancement, no surgical treatment, and the use of radiotherapy were identified as independent predictors of decreased OS in skull OSC.

Conclusion

Overall prognosis is better for EWS compared to OSC. Chondroblastic OSC have the best overall survival, while OSC associated with Paget’s disease of the bone has the poorest overall survival.

Pediatric Ewing sarcoma of the head and neck: A retrospective survival analysis

OBJECTIVE

To determine the demographics, treatment modalities, and overall survival of pediatric Ewing sarcoma of the head and neck.

METHODS

The National Cancer Institute's Surveillance, Epidemiology, and End Results database was used to identify cases of pediatric Ewing sarcoma of the head and neck between 1973 and 2015. Additional variables collected included age, gender, ethnicity, tumor grade, staging, treatment modality, and follow-up time. Kaplan-Meier survival curves were generated and overall survival was calculated.

RESULTS

One hundred and twenty-seven cases of pediatric Ewing sarcoma were identified. The majority of patients were male (52.8%), white (88.2%), and non-Hispanic (75.6%), and the mean age at diagnosis was 10.5 years. The most common tumor sites were bones and joints of the skull and face (45.5%), followed by soft tissue of the head, face, and neck (25.2%), followed by the mandible (13.4%). Most patients (69.2%) had some type of surgery, 70.0% received radiation, and 92.1% received chemotherapy as part of their treatment. Overall 1-, 5-, and 10-year survival was 91.1%, 72.9%, and 68.2%, respectively. There was no significant difference in survival based on patient gender, age, tumor location, radiation, or chemotherapy treatment.

CONCLUSION

This study demonstrates that pediatric patients with Ewing sarcoma of the head and neck most commonly have stage II disease, no distant metastasis, and are treated with chemotherapy, with or without radiation. One, five, and ten-year survival are 91.1%, 72.9%, and 68.2%, respectively, and age, gender, and radiation do not seem to affect prognosis.

A phase II study of temsirolimus and liposomal doxorubicin for patients with recurrent and refractory bone and soft tissue sarcomas

Background

Relapsed and refractory sarcomas continue to have poor survival rates. The cancer stem cell (CSC) theory provides a tractable explanation for the observation that recurrences occur despite dramatic responses to upfront chemotherapy. Preclinical studies demonstrated that inhibition of the mechanistic target of rapamycin (mTOR) sensitizes the CSC population to chemotherapy.

Methods

Here we present the results of the Phase II portion of a Phase I/II clinical trial that aimed to overcome the chemoresistance of sarcoma CSC by combining the mTOR inhibitor temsirolimus (20 mg/m² weekly) with the chemotherapeutic agent liposomal doxorubicin (30 mg/m² monthly).

Results

Fifteen patients with relapsed/refractory sarcoma were evaluable at this recommended Phase 2 dose level. The median progression free survival was 315 days (range 27–799). Response rate, defined as stable disease or better for 60 days, was 53%. Nine of the patients had been previously treated with doxorubicin. Therapy was well tolerated. In a small number of patients, pre- and post- treatment tumor biopsies were available for assessment of ALDH expression as a marker of CSCs and showed a correlation between response and decreased ALDH expression. We also found a correlation between biopsy-proven inhibition of mTOR and response.

Conclusions

Our study adds to the literature supporting the addition of mTOR inhibition to chemotherapy agents for the treatment of sarcomas, and proposes that a mechanism by which mTOR inhibition enhances the efficacy of chemotherapy may be through sensitizing the chemoresistant CSC population. Further study, ideally with pre- and post-therapy assessment of ALDH expression in tumor cells, is warranted.

Trial registration The trial was registered on clinicaltrials.gov (NCT00949325) on 30 July 2009. http://www.editorialmanager.com/csrj/default.aspx

Oncogenic role of SFRP2 in p53-mutant osteosarcoma development via autocrine and paracrine mechanism

Osteosarcoma (OS), the most common primary bone tumor, is highly metastatic with high chemotherapeutic resistance and poor survival rates. Using induced pluripotent stem cells (iPSCs) generated from Li-Fraumeni syndrome (LFS) patients, we investigate an oncogenic role of secreted frizzled-related protein 2 (SFRP2) in p53 mutation-associated OS development. Interestingly, we find that high SFRP2 expression in OS patient samples correlates with poor survival. Systems-level analyses identified that expression of SFRP2 increases during LFS OS development and can induce angiogenesis. Ectopic SFRP2 overexpression in normal osteoblast precursors is sufficient to suppress normal osteoblast differentiation and to promote OS phenotypes through induction of oncogenic molecules such as FOXM1 and CYR61 in a β-catenin-independent manner. Conversely, inhibition of SFRP2, FOXM1, or CYR61 represses the tumorigenic potential. In summary, these findings demonstrate the oncogenic role of SFRP2 in the development of p53 mutation-associated OS and that inhibition of SFRP2 is a potential therapeutic strategy.

Pediatric Musculoskeletal Imaging: The Indications for and Applications of PET/Computed Tomography

The use of PET/computed tomography (CT) for the evaluation and management of children, adolescents, and young adults continues to expand. The principal tracer used is 18F-fluorodeoxyglucose and the principal indication is oncology, particularly musculoskeletal neoplasms. The purpose of this article is to review the common applications of PET/CT for imaging of musculoskeletal issues in pediatrics and to introduce the use of PET/CT for nononcologic issues, such as infectious/inflammatory disorders, and review the use of 18F-sodium fluoride in trauma and sports-related injuries.

Matrix stiffness regulates epithelial-mesenchymal transition via cytoskeletal remodeling and MRTF-A translocation in osteosarcoma cells

Matrix stiffness is known to alter cellular behaviors in various biological contexts. Previous investigations have shown that epithelial-mesenchymal transition (EMT) promotes the progression and invasion of tumor. Mechanical signaling is identified as a regulator of EMT. However, the molecular mechanisms underlying the influence exerted by matrix stiffness on EMT in osteosarcoma remains largely unknown. Using polyacrylamide hydrogel model, we investigate the effects of matrix stiffness on EMT and migration in osteosarcoma. Our data indicates that high matrix stiffness regulates cell morphology and promotes EMT and migration in osteosarcoma MG63 cell line in vitro. Notably, matrix stiffness promotes polymerization of actin and nuclear accumulation of myocardin-related transcription factor A (MRTF-A). Furthermore, inhibiting MRTF-A by CCG 203971 significantly reduces EMT and migration on rigid gels. These data suggest that matrix stiffness of the tumor microenvironment actively regulate osteosarcoma EMT and migration through cytoskeletal remodeling and translocation of MRTF-A, which may contribute to cancer progression.

Profiling targetable immune checkpoints in osteosarcoma

Osteosarcomas are aggressive bone tumors for which therapeutic advances have not improved over several decades. Unlike most pediatric tumors, the osteosarcoma genome is remarkably unstable, characterized by numerous copy number alterations and chromosomal structural aberrations. In this study, we asked if the targetable immune checkpoints CD274 (PD-L1), PDCD1LG2 (PD-L2), CD276 (B7-H3) and IDO1 are impacted by copy number alterations in osteosarcoma. Of the 215 osteosarcoma samples investigated, PD-L1/PD-L2, B7-H3 and IDO1 were independently gained at frequencies of approximately 8-9%, with a cumulative frequency of approximately 24%. RNA sequencing data from two independent cohorts revealed that B7-H3 is the most highly expressed immune checkpoint gene among the four investigated. We also show that IDO1 is preferentially expressed in pediatric solid tumors and that increased protein expression of B7-H3 and IDO1 are significantly associated with inferior survival in patient samples. Using human osteosarcoma cell lines, we demonstrate that IDO1 is gained in MG63 and G292 cells and that the IDO1 inhibitor, epacadostat, inhibits the enzymatic activity of IDO1 in a dose-dependent manner in these cells. Together, these data reveal the genomic and transcriptomic profiles of PD-L1, PD-L2, B7-H3 and IDO1 in osteosarcoma and identifies a potential context for targeted immunotherapeutic intervention in a subset of patients.

Efficient tumor transduction and antitumor efficacy in experimental human osteosarcoma using retroviral replicating vectors

Retroviral replicating vectors (RRVs) have achieved efficient tumor transduction and enhanced therapeutic benefit in a wide variety of cancer models. Here, we evaluated two different RRVs derived from amphotropic murine leukemia virus (AMLV) and gibbon ape leukemia virus (GALV), which utilize different cellular receptors (PiT-2 and PiT-1, respectively) for viral entry, in human osteosarcoma cells. Quantitative RT-PCR showed that low levels of expression of both receptors were observed in normal and non-malignant cells. However, high PiT-2 (for AMLV) and low PiT-1 (for GALV) expression was observed in most osteosarcoma cell lines. Accordingly, AMLV expressing the green fluorescent protein gene infected and replicated more efficiently than GALV in most osteosarcoma cell lines. Furthermore, RRVs expressing the cytosine deaminase prodrug activator gene showed differential cytotoxicity that correlated with the results of viral spread. AMLV-RRV-mediated prodrug activator gene therapy achieved significant inhibition of subcutaneous MG-63 tumor growth over GALV in nude mice. These data indicate that AMLV vectors predominate over GALV in human osteosarcoma cells. Moreover, our findings support the potential utility of the two RRVs in personalized cancer virotherapy on the basis of receptor expression.

Brazilin induces FOXO3A-dependent autophagic cell death by disturbing calcium homeostasis in osteosarcoma cells

PURPOSE

Osteosarcoma is a common primary malignant bone tumour, and its cure rate has stagnated over the past 25-30 years. Brazilin, a purified natural product from sappan wood (Caesalpinia sappan L.), has been proved to possess potent anti-cancer effects. In this study, we investigated the anti-cancer effect of brazilin on human osteosarcoma and elucidated the underlying mechanisms.

METHODS

We exposed MG-63 cells to different concentrations of brazilin (5, 10 and 20 µM) for 24 h. Western blotting, immunocytofluorescence, luciferase reporter assays, and RT-PCR were used to evaluate whether brazilin activates FOXO family-dependent autophagy.

RESULTS

Brazilin increased autophagic flux in the human osteosarcoma cell line MG-63, as evidenced by the upregulation of LC3-II and the downregulation of P62/SQSTM1. Moreover, the pharmacological or genetic blockade of autophagy decreased brazilin-induced cell death, indicating that brazilin triggered autophagic cell death in MG-63 cells. Specifically, brazilin induced FOXO3A(Ser7) phosphorylation, activated FOXO3A nuclear translocation and increased FOXO3A reporter activity, which contributed to the expression of autophagy-related genes and subsequently initiated autophagic cell death in MG-63 cells. Importantly, the increased expression and nuclear translocation of FOXO3A were tightly related to the disturbance of calcium homeostasis, which could be prevented by chelating intracellular calcium.

CONCLUSIONS

Taken together, these data demonstrate that brazilin induces osteosarcoma cell death by inducing excessive autophagy, which is mediated through the Ca²⁺-FOXO3A pathway. Our study provides a new anti-tumour mechanism for brazilin treatment in osteosarcoma patients.

In vitro and in vivo characterization of stem-like cells from canine osteosarcoma and assessment of drug sensitivity

Cancer stem cell (CSC) self-renewing and drug resistance cause treatment failure and tumor recurrence. Osteosarcoma is an aggressive bone tumor characterized by biological and molecular heterogeneity, possibly dependent on CSCs. CSC identification in osteosarcoma and their efficient targeting are still open questions. Spontaneous canine osteosarcoma shares clinical and biological features with the human tumors, representing a model for translational studies. We characterized three CSC-enriched canine osteosarcoma cultures. In serum-free conditions, these CSC cultures grow as anchorage-independent spheroids, show mesenchymal-like properties and in vivo tumorigenicity, recapitulating the heterogeneity of the original osteosarcoma. Osteosarcoma CSCs express stem-related factors (Sox2, Oct4, CD133) and chemokine receptors and ligands (CXCR4, CXCL12) involved in tumor proliferation and self-renewal. Standard drugs for osteosarcoma treatment (doxorubicin and cisplatin) affected CSC-enriched and parental primary cultures, showing different efficacy within tumors. Moreover, metformin, a type-2 diabetes drug, significantly inhibits osteosarcoma CSC viability, migration and self-renewal and, in co-treatment with doxorubicin and cisplatin, enhances drug cytotoxicity. Collectively, we demonstrate that canine osteosarcoma primary cultures contain CSCs exhibiting distinctive sensitivity to anticancer agents, as a reliable experimental model to assay drug efficacy. We also provide proof-of-principle of metformin efficacy, alone or in combination, as pharmacological strategy to target osteosarcoma CSCs.

Long noncoding RNA NBAT1 negatively modulates growth and metastasis of osteosarcoma cells through suppression of miR-21

Osteosarcoma (OS) is the most common primary bone malignancies. Long noncoding RNAs (lncRNAs) are key regulatory RNAs which takes part in several biological processes. LncRNA neuroblastoma associated transcript 1 (NBAT1) is a newly identified functional lncRNA. NBAT1 functions as a tumor suppressor in some cancers. However, the expression pattern, the biological function and the mechanisms of NBAT1 in OS progress have not been elucidated. In this study, for the first time, we found that NBAT1 expression is downregulated in OS tissues and cell lines and is associated with clinical stage, distant metastasis and poor prognosis. Loss- and gain-of-function assays showed that NBAT1 played a negative regulatory role in OS growth and metastasis in vitro and in vivo. Further investigation demonstrated that NBAT1 physically interacted with miR-21 and then suppressed its expression. NBAT1 also regulated downstream genes targeted by miR-21, including PTEN, PDCD4, TPM1 and RECK. These findings may extend the function of NBAT1 in tumor progression and provide a novel target for OS treatment.

Pediatric soft tissue sarcoma of the limbs: clinical outcome of 97 patients

PURPOSE

Soft tissue sarcomas (STS) of the extremities in children are a heterogeneous group of tumors with a very different prognosis for which optimal treatment remains controversial.

PATIENTS AND METHODS

We retrospectively evaluated 97 patients younger than 15 years old affected by limb soft tissue sarcomas. All cases were histologically revised, and tumor grade was assessed according to the FNLCC system. Thirty-two were rhabdomyosarcoma (RMS) and 65 non-rhabdomyosarcoma (NRMSTS); among these, 40 (61.5%) were grade 3 according to FNLCC classification. Overall survival, local recurrence and distant metastasis were analyzed.

RESULTS

Overall survival was 77.8% at 5 years and 69.7% at 10 years. Among grade 3 tumors, RMS had a worse prognosis over NRSTS. Similarly, tumors larger than 5 cm had a worse prognosis compared to smaller ones. Local recurrence-free survival was 90.7% at 5 years and 87.1% at 10 years with a better local control in grade 3 NRSTS over RMS and in tumors smaller than 2 cm.

CONCLUSION

Children affected by extremities RMS were confirmed to have the worst prognosis, in particular in case of metastasis at presentation. Differently from adult patients, hand and feet locations are frequent site for STS and 2 cm diameter should be taken as cut off for higher risk of LR. Similarly to adulthood STS, grading correlates with prognosis in NRSTS. The identification of prognostic variables should enable risk-adapted therapies to be planned.

Long noncoding RNA LeXis promotes osteosarcoma growth through upregulation of CTNNB1 expression

Osteosarcoma (OS) is the most common primary bone cancer in adolescents and children. Long noncoding RNAs (lncRNAs) contain > 200 nucleotides and do not have protein-coding ability. Liver-expressed LXR-induced sequence (LeXis) is a newly identified functional lncRNA. However, its expression pattern, biological function, and molecular mechanism in OS progression are unclear. The present study is the first to show that LeXis expression was upregulated in OS tissues. Increased LeXis expression was significantly correlated with high tumor stage, large tumor size, and poor prognosis. Our findings highlight the oncogenic activity of lncRNA LeXis in OS growth. Results of functional assays showed that LeXis promoted OS growth both in vitro and in vivo. Mechanistic investigation showed that LeXis directly interacted with miR-199a and suppressed its expression. Moreover, LeXis increased CTNNB1 expression by functioning as a ceRNA of CTNNB1 against miR-199a. These findings may have important implications for developing novel therapeutic strategies for OS.