Survival of pediatric patients after relapsed osteosarcoma: the St. Jude Children's Research Hospital experience

Effects of matrix viscoelasticity on cell-matrix interaction, actin cytoskeleton organization, and apoptosis of osteosarcoma MG-63 cells

Many recent reports have shown the effects of viscoelasticity of the extracellular matrix on the spreading, migration, proliferation, survival and cell-matrix interaction of mesenchymal stem cells and normal cells. However, the effect of matrix viscoelasticity on the behavior of tumor cells is still in the state of preliminary exploration. To this aim, we prepared a viscoelastic hydrogel matrix with a storage modulus of about 2 kPa and a loss modulus adjustable from 0 to 600 Pa, through adding linear alginate and regulating the compactness of a polyacrylamide covalent network. Overall, the addition of viscous components inhibited the apoptosis of osteosarcoma MG-63 cells, while it promoted their spreading and proliferation and in particular led to a well-developed cytoskeleton organization. However, with the increase of the viscous fraction, this trend was reversed, and the apoptosis of MG-63 cells gradually increased with gradually decreased spreading and proliferation, accompanied by a surprising manner change of the cytoskeleton from fusiform cells dominated by focal adhesion to dendritic cells dominated by pseudopodia. Besides the upregulation of MAPK, Ras, Rap1 and PI3K-Akt pathways commonly involved in mechanotransduction, the upregulation of the Wnt pathway and inhibited endoplasmic reticulum stress-mediated apoptosis were observed for the viscous matrix with a low loss modulus. The high viscosity matrix showed additional involvement of Hippo and NF-kappa B signaling pathways related to the cell-matrix interaction, with downregulation of the endoplasmic reticulum stress pathway and upregulation related to mitochondrial organization. Our study would provide insight into the effect of viscosity on fundamental behaviors of tumor cells and might have important implications in designing antitumor materials.

Tyrosine kinase inhibitor therapy in pediatric sarcoma: Prognostic implications of pulmonary metastatic cavitation

PURPOSES

This study aims to ascertain the prevalence of cavitations in pulmonary metastases among pediatric and young adult patients with sarcoma undergoing tyrosine kinase inhibitor (TKI) therapy, and assess whether cavitation can predict clinical response and survival outcomes.

METHODS

In a single-center retrospective analysis, we examined chest computed tomography (CT) scans of 17 patients (median age 16 years; age range: 4-25 years) with histopathologically confirmed bone (n = 10) or soft tissue (n = 7) sarcoma who underwent TKI treatment for lung metastases. The interval between TKI initiation and the onset of lung nodule cavitation and tumor regrowth were assessed. The combination of all imaging studies and clinical data served as the reference standard for clinical responses. Progression-free survival (PFS) was compared between patients with cavitating and solid nodules using Kaplan-Meier survival analysis and log-rank test.

RESULTS

Five out of 17 patients (29%) exhibited cavitation of pulmonary nodules during TKI therapy. The median time from TKI initiation to the first observed cavitation was 79 days (range: 46-261 days). At the time of cavitation, all patients demonstrated stable disease. When the cavities began to fill with solid tumor, 60% (3/5) of patients exhibited progression in other pulmonary nodules. The median PFS for patients with cavitated pulmonary nodules after TKI treatment (6.7 months) was significantly longer compared to patients without cavitated nodules (3.8 months; log-rank p-value = .03).

CONCLUSIONS

Cavitation of metastatic pulmonary nodules in sarcoma patients undergoing TKI treatment is indicative of non-progressive disease, and significantly correlates with PFS.

Survival outcomes and surgical morbidity based on surgical approach to pulmonary metastasectomy in pediatric, adolescent and young adult patients with osteosarcoma

BACKGROUND

Thoracotomy is considered the standard surgical approach for the management of pulmonary metastases in osteosarcoma (OST). Several studies have identified the advantages of a thoracoscopic approach, however, the clinical significance of thoracotomy compared to thoracoscopy is yet to be evaluated in a randomized trial.

AIMS

The primary aim was to determine the survival outcomes in OST patients based on surgical approach for pulmonary metastasectomy (PM) and secondary aim was to assess the post-operative morbidities of OST PM through various surgical approaches.

MATERIALS AND METHODS

We conducted a single institution retrospective study to compare survival outcomes and surgical morbidity according to the surgical approach of the management of pulmonary metastases in patients with OST.

RESULTS

Sixty-one patients with OST underwent PM. Twenty-one patients were metastatic at diagnosis and underwent PM during primary treatment; nine had thoracotomy, six thoracoscopy, and six combined thoracoscopy with thoracotomy (CTT). Forty-three patients with first pulmonary relapse or progression underwent PM; 18 had thoracotomy, 16 thoracoscopy and nine CTT. There was no difference in survival between surgical approaches. There were significantly more postoperative morbidities associated with thoracotomy for initial PM (pain and postoperative chest tube placement), and for PM at first relapse (pneumothoraces, pain, Foley catheter use and prolonged hospitalizations).

CONCLUSION

Our study demonstrates that patients with OST pulmonary metastases have comparable poor outcomes despite varying surgical approaches for PM. There were significantly more postoperative morbidities associated with thoracotomy for PM. Surgical bias and other competing risks could not be assessed given the limitations of a retrospective study and may be addressed in a prospective trial evaluating surgical approach for PM in OST.

Solitary pulmonary metastases at first recurrence of osteosarcoma: Presentation, treatment, and survival of 219 patients of the Cooperative Osteosarcoma Study Group

BACKGROUND

To evaluate patient and tumour characteristics, treatment and their impact on survival in patients with a solitary pulmonary metastasis at first relapse of high-grade osteosarcoma.

PROCEDURE

Two-hundred and nineteen consecutive patients who had achieved a complete surgical remission and then developed a solitary pulmonary metastasis at first recurrence of high-grade osteosarcoma were retrospectively reviewed.

RESULTS

Two hundred and three (94.9%) of 214 patients achieved a second complete remission. After a median time from initial diagnosis of osteosarcoma to first relapse of 2.3 years (range, 0.3-18.8 years), actuarial post-relapse overall survival after 2 and 5 years was 72.0% and 51.2%. Post-relapse event-free survival was 39.1% and 31.1%. Median follow-up time was 3.2 years (range, 0.1-29.4 years). A longer time until first relapse and diagnosis due to imaging were positive prognostic factors in uni- and multivariate analyses, as were a second complete surgical remission and, in regard to death, the absence of a subsequent relapse. The use of salvage chemotherapy and radiotherapy were not associated with patient outcomes, nor was the surgical approach (thoracoscopy vs. thoracotomy) nor the exploration (uni- vs. bilateral).

CONCLUSION

Approximately half of the patients who experience a solitary pulmonary relapse at first recurrence of osteosarcoma remain alive 5 years after this first relapse. Only one third will remain disease-free. A complete surgical resection of the lesion is essential for long-term survival while relapse chemotherapy does not seem to improve survival. Innovative therapies are required to improve outcomes.

Clinical Outcomes of Patients With Osteosarcoma Experiencing Relapse or Progression: A Single-institute Experience

BACKGROUND

Patients with osteosarcoma who experience relapse or progression [R/P] have a poor prognosis.

METHODS

Data from 30 patients who experienced R/P among 59 with a diagnosis of high-grade osteosarcoma, who were younger than 40 years old between 2000 and 2019, were retrospectively analyzed to identify prognostic and therapeutic factors influencing their outcomes.

RESULTS

The 5-year overall survival [OS] rates after the last R/P of patients experiencing first [n=30], second [n=14], and third [n=9] R/P were 50.3%, 51.3%, and 46.7%, respectively. Multivariate analysis did not identify any independent risk factors affecting OS. The 5-year PFS rate of the 30 patients after first R/P was 22.4%, and multivariate analysis identified histologic subtype and curative local surgery as independent risk factors influencing PFS. Long [>6 mo] partial response was observed in three patients treated using temozolomide+etoposide, irinotecan+carboplatin, or regorafenib.

CONCLUSIONS

OS rate in the patients with osteosarcoma experiencing R/P included in this study was markedly higher than that reported previously, mainly due to the surgical total removal of tumors, even after subsequent R/P. The recent establishment of salvage chemotherapy or molecular targeted therapy may also increase survival rates in a subgroup of patients.

Survival estimates of childhood malignancies treated at the Mexican telethon pediatric oncology hospital

BACKGROUND

Pediatric cancer incidence in Mexico is ~160/million/year with leukemias making 49.8% of the cases. While survival rates have been reported in various Mexican studies, no data is available from the Telethon Pediatric Oncology Hospital-HITO, a nonprofit private institution specialized exclusively in comprehensive pediatric oncology care in the country that closely follows high-income countries' advanced standards of cancer care.

AIM

To determine overall survival (OS) and relapse-free survival (RFS) in patients treated at HITO between December 2013 and February 2018.

METHODS AND RESULTS

Secondary analysis of data extracted from medical records. It included 286 children aged 0-17 years diagnosed with various cancers grouped into three categories based on location: (1) Acute lymphoblastic leukemia (ALL), (2) tumors within the central nervous system (TWCNS), and (3) tumors outside the CNS (TOCNS). OS and RFS rates for patients who completed 1 (n = 230) and 3 (n = 132) years of follow-up after admission were computed by sex, age, and cancer location, and separately for a subsample (1-year = 191, 3-years = 110) who fulfilled the HITO criteria (no prior treatment, underwent surgery/chemotherapy when indicated, and initiated therapy). TOCNS accounted for 45.1%, but ALL was the most frequent single diagnosis with 28%. Three-year OS for patients with ALL, TWCNS, and TOCNS who fulfilled the HITO criteria were 91.9%, 86.7%, and 79.3%, respectively; for 3-year RFS these were 89.2%, 60%, and 72.4%. Boys showed slightly higher OS and RFS, but no major differences or trends were seen by age group.

CONCLUSION

This study sets a relevant reference in terms of survival and relapse for children with cancer in Mexico treated at a private oncology center that uses a comprehensive and integrated therapeutic model.

Effects of a Web-Based Pediatric Oncology Legacy Intervention on the Coping of Children With Cancer

BACKGROUND

Recurrent or refractory cancer often results in substantial and extensive physical, emotional, psychosocial, and spiritual burdens for children and their families. However, the therapeutic benefits of legacy interventions in children with recurrent or refractory cancer have been examined only recently, with limited attention to specific effects on children's coping abilities.

OBJECTIVE

The purpose of this study was to determine the effects of a digital storytelling-legacy intervention on the adaptive coping of children with recurrent or refractory cancer.

METHODS

This study used a 2-arm randomized, waitlist-controlled trial design. A total of 150 children with recurrent or refractory cancer and their parents were recruited via Facebook advertisements.

RESULTS

The analysis sample included 92 dyads (35-intervention group, 57-control group). The legacy intervention showed small and statistically nonsignificant effects on primary-control and disengagement coping strategies among children with recurrent or refractory cancer.

CONCLUSIONS

Legacy interventions using readily accessible digital storytelling have the potential to enhance the adaptive coping skills among children with recurrent or refractory cancer. Further research should determine how to enhance interventions tailored to this population to optimize the benefits.

The Outcome of Discontinuing Tyrosine Kinase Inhibitors in Advanced Sarcoma Following a Favorable Tumor Response to Antiangiogenics Therapy

(1) Background: The use of antiangiogenic TKIs (AA-TKIs) has recently emerged as a major paradigm shift in the treatment of advanced sarcoma. However, the feasibility of drug holidays for patients demonstrating a very favorable response remains unknown. (2) Methods: We aim to explore the outcomes of patients with advanced sarcoma who discontinued AA-TKIs after a (near-) complete remission or were long-term responders. Patients with advanced disease were included if they had bilateral or multiple lung metastases, extrapulmonary recurrence, a short disease-free interval, etc., at the initiation of AA-TKIs. (3) Results: A total of 22 patients with AA-TKI discontinuation were analyzed, with a median follow-up of 22.3 months post-discontinuation. Prior to discontinuation, there were four drug-induced complete remissions (CRs), twelve surgical CRs, and six long-term responders. Disease progression was observed in 17/22 (77.3%) patients, with a median of 4.2 months. However, since the majority were still sensitive to the original AA-TKIs and amenable to a second surgical remission, 7 out of these 17 patients achieved a second CR after disease progression and were thus considered as relapse-free post-discontinuation (pd-RFS). Therefore, the pd-RFS and post-discontinuation overall survival (pd-OS) in the last follow-up were 12/22 (54.5%) and 16/22 (72.7%), respectively. Remarkably, surgical CR and drug tapering off (versus abrupt stopping) were associated with a greater pd-RFS and pd-OS (p < 0.05). Furthermore, higher necrosis rates (p = 0.040) and lower neutrophil-to-lymphocyte ratios (NLR) (p = 0.060) before discontinuation tend to have a better pd-RFS. (4) Conclusions: Our results suggest that AA-TKI discontinuation with a taper-off strategy might be safe and feasible in highly selected patients with advanced sarcoma. Surgical CR, NLR, and tumor necrosis rates before discontinuation were potential biomarkers for AA-TKI withdrawal.

The Role of a Multidisciplinary Team in the Diagnosis and Treatment of Bone and Soft Tissue Sarcomas: A Single-Center Experience

Bone and soft tissue sarcomas with complex and varied clinical, imaging, and pathological characteristics cannot be diagnosed and treated by a single discipline, as each discipline has some limitations. This study aimed to explore the role of a multidisciplinary team (MDT) in the diagnosis and treatment of bone and soft tissue sarcomas over the past four consecutive years. The subjects were 269 patients discussed during MDT meetings at a Bone and Soft Tissue Sarcomas Center in South China. The diagnosis, relapse diagnosis, unplanned resection, management of pulmonary nodules, and treatment of refractory and advanced tumors were compared to similar data provided in the literature to (i) determine whether the MDT significantly affected the diagnosis and treatment of bone and soft tissue sarcomas, and (ii) explore trends in the types of patients with bone and soft tissue sarcomas and treatment decision-making since the establishment of the MDT. Results revealed that the MDT significantly improved preoperative diagnostic accuracy for patients with bone and soft tissue sarcomas; the accuracy of diagnosis and relapse diagnosis by the MDT reached 95.42% and 100%, respectively. After an MDT discussion, the positive pathology rate for extended resection after unplanned resection was 81.2%. The overall accuracy of the MDT in determining the nature of pulmonary nodules was 87.1-91.9%. For patients presenting with pulmonary nodules in osteosarcoma, no statistically significant difference in survival was shown between cases discussed by the MDT and those without an MDT discussion (p = 0.5751). Collectively, the MDT can play a positive role in accurate preoperative diagnosis, relapse diagnosis, the decision to extend resection after an unplanned resection, and the diagnostic accuracy of pulmonary nodules.

Controversies and Challenges in the Management of Osteosarcoma-an Indian Perspective

Osteosarcoma (OGS) is the most common primary bone tumor in children and adolescents which requires a multidisciplinary approach to management. Although chemotherapy and surgery can cure more than half of localized OGS cases, the unique challenges faced by resource-limited countries like India make this outcome difficult to achieve. Various questions in the management of OGS including role of high-dose methotrexate (HDMTX) in neoadjuvant setting, triplet vs doublet chemotherapy, intensification of chemotherapy based on response in setting of doublet, and indigenous prosthesis in setting of limb salvage need to be defined. Similarly, in the metastatic and recurrent setting, questions regarding intent of treatment, indications of chemotherapy, timing of surgery, and role of targeted therapies need clarification. Lack of randomized trials from India makes definite conclusions difficult, but an attempt can be made to define the best approach in the Indian scenario from available evidence. Hence, a critical review of literature from India and the West was done to define possible management approaches and highlight the lacuna for future research.

Renal metastasis of osteosarcoma after multiple pulmonary metastases: A case report and review of literature

Renal metastasis of osteosarcoma is a rare entity, with paucity of reported cases in the literature. We report a case of a 20-year-old gentleman who was diagnosed with right distal femur osteosarcoma, complicated with multiple pulmonary recurrences. At two-year-and-a-half interval post-treatment completion, the patient developed right flank pain and frank haematuria. Contrasted abdominal computed tomography revealed a right renal mass with calcification and perinephric haematoma. A right radical nephrectomy was undertaken and histopathological examination showed metastatic condroblastic osteosarcoma. A literature review on renal metastasis secondary to osteosarcoma was performed and we present a report and discussion of these cases.

miR-1297 inhibits osteosarcoma cell proliferation and growth by targeting CCND2

Cyclin D2 (CCND2) is abnormally overexpressed in many tumor types and has been associated with tumor cell proliferation. Although the important role of miR-1297 is well established, the molecular mechanism between CCND2 and miR-1297 in osteosarcoma (OS) has not been determined. In the present study, we found CCND2 was highly expressed in OS cells, and its downregulation suppressed cell proliferation, resulting in G1 phase cell cycle arrest. In contrast, miR-1297 was lowly expressed in OS compared to normal tissue. Several data platforms predicted that CCND2 was a target of miR-1297, which was validated by a dual-luciferase reporter assay that revealed miR-1297 could bind with CCND2-3'UTR. miR-1297 overexpression greatly inhibited CCND2 protein expression and exerted the same phenotypic effect as CCND2 downregulation in OS cells. Furthermore, miR-1297 inhibition could also be rescued by CCND2. Nude mice injected cells stable overexpressing miR-1297 OS cells showed lower size and tumor weight. Moreover, lower fluorescence activity recorded by in vivo imaging system and bone erosion revealed by microCT in the miR-1297 group demonstrated miR-1297 inhibited OS tumor growth via CCND2. Our findings demonstrated that miR-1297 can inhibit proliferation and tumor growth in OS by directly targeting CCND2, which indicates that miR-1297 may represent a novel therapeutic target for OS.

Osteogenic and anti-tumor Cu and Mn-doped borosilicate nanoparticles for syncretic bone repair and chemodynamic therapy in bone tumor treatment

Critical bone defects caused by extensive excision of malignant bone tumor and the probability of tumor recurrence due to residual tumor cells make malignant bone tumor treatment a major clinical challenge. The present therapeutic strategy concentrates on implanting bone substitutes for defect filling but suffers from failures in both enhancing bone regeneration and inhibiting the growth of tumor cells. Herein, Cu and Mn-doped borosilicate nanoparticles (BSNs) were developed for syncretic bone repairing and anti-tumor treatment, which can enhance bone regeneration through the osteogenic effects of Cu²⁺ and Mn³⁺ ions and meanwhile induce tumor cells apoptosis through the hydroxyl radicals produced by the Fenton-like reactions of Cu²⁺ and Mn³⁺ ions. In vitro study showed that both osteogenic differentiation of BMSCs and angiogenesis of endothelial cells were promoted by BSNs, and consistently the critical bone defects of rats were efficiently repaired by BSNs through in vivo evaluation. Meanwhile, BSNs could generate hydroxyl radicals through Fenton-like reactions in the simulated tumor microenvironment, promote the generation of intracellular reactive oxygen species, and eventually induce tumor cell apoptosis. Besides, subcutaneous tumors of mice were effectively inhibited by BSNs without causing toxic side effects to normal tissues and organs. Altogether, Cu and Mn-doped BSNs developed in this work performed dual functions of enhancing osteogenesis and angiogenesis for bone regeneration, and inhibiting tumor growth for chemodynamic therapy, thus holding a great potential for syncretic bone repairing and anti-tumor therapy.

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Dual-functional bioactive borosilicate nanoparticles were successfully synthesized.

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Incorporation of Cu and Mn to the nanoparticles enhanced osteogenesis and angiogenesis.

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Cu and Mn doped borosilicate nanoparticles inhibited tumor by producing ·OH.

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Potential syncretic bone repair and chemodynamic therapy developed for bone tumor treatment.

The Roles of KIFC1 in the Development of Osteosarcoma: Characterization of Potential Therapeutic Targets

Background

As an important member of the mitotic kinesin family, kinesin family member C1 (KIFC1) is abnormally expressed in a variety of tumors. However, the roles of KIFC1 in the development of osteosarcoma (OS) have never been elucidated.

Methods

The expression of KIFC1 in OS tissues which was detected by immunohistochemistry (IHC) staining was further confirmed by Gene Expression Profiling Interactive Analysis 2 (GEPIA2) database. The relationship between KIFC1 and CDC20 was analyzed by clinical data, STRING database, and GEPIA2 database. Survival analysis was performed through GEPIA2 database. To elucidate the roles of KIFC1 in OS, MG-63 and U-2 OS cells were treated with short hairpin RNA (shRNA) to knock down KIFC1 expression, and the knockdown efficiency was validated with quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blotting (WB). Moreover, colony formation and Cell Counting Kit-8 (CCK-8) assays were utilized to evaluate cell proliferation.

Results

According to IHC staining and GEPIA2 analysis, the expression of KIFC1 in OS tissues was significantly higher than that in adjacent normal tissues, which was inversely connected to the prognosis. These results were consistent with our clinical data. Besides, KIFC1 was positively correlated with CDC20. In addition, KIFC1 shRNA could effectively silence KIFC1 expression in MG-63 and U-2 OS cells. Furthermore, the knockdown of KIFC1 inhibited the cell proliferation ability with increased cell apoptosis in MG-63 and U-2 OS cells.

Conclusion

KIFC1 was significantly upregulated in OS and promoted OS progression by cell proliferation. These findings offered new clues for OS diagnosis and prognosis, suggesting KIFC1 could be a potential therapeutic target for OS in further study.

Prognostic factors and treatment of relapsed osteosarcoma: A monocentric Tunisian retrospective study

BACKGROUND

This study aimed to explore the treatment modalities of relapsed osteosarcoma, treatment results, and prognostic factors.

METHODS

We conducted a retrospective study of patients treated for relapsed osteosarcoma between 2005 and 2019. Patient survival was compared according to age, performance status, time to relapse, and surgical treatment at the relapse. Values of p<0.05 were considered to indicate statistical significance.

RESULTS

We included 49 patients who were treated for osteosarcoma. During the 13-year study period, 16 patients had relapsed osteosarcoma (32.7%). Prognostic factors of relapse were age over 18 years (p = 0.03), axial tumors (p = 0.01), and positive surgical margins (p = 0.018). Nine patients had palliative chemotherapy at the time of relapse. After a median follow-up of 8 months (range: 4-65 months), the overall survival at 1 year, 2 years, and 5 years after diagnosis of the relapse was 46.7%, 31.1%, and 20.7%, respectively. Relapsed osteosarcoma patients who had good performance status, late relapse (after 12 months), as well as surgery of the relapsed disease had better overall survival (OS).

CONCLUSION

Surgical treatment of relapsed osteosarcoma should be performed whenever possible since it improves significantly the survival of patients. Good performance status and late relapse were also associated with better survival.

Pediatric Osteosarcoma: Pearls and Pitfalls

Osteosarcoma is a malignant bone tumor most commonly presenting in children. It has a bimodal distribution with a peak incidence occurring during the ages of 10-14 years old and in adults greater than age 65. The first peak of osteosarcoma correlates with the increased proliferation of bone during the pubertal growth period. Osteosarcoma most frequently presents with localized bone pain, swelling, and an antalgic gait. The patient may attribute symptoms to trauma or strenuous exercise, causing the patient to be managed conservatively. In these cases, the pain persists and eventually leads to further evaluation. The most common type of osteosarcoma is the conventional high-grade osteosarcoma. For conventional osteosarcoma, the diagnosis is typically made or strongly suggested based upon the initial radiographic appearance. Other types of osteosarcomas include low grade central, telangiectatic, small-cell, surface and intracortical. Consequently, it is important for radiologists to be aware of these subtypes and the imaging features that differentiate them from other etiologies to prevent a delay in treatment.

Phase I study of pegylated liposomal doxorubicin and cisplatin in patients with advanced osteosarcoma

PURPOSE

The repeated use of doxorubicin is limited due to dose-limiting cardiac toxicity. Pegylated liposomal doxorubicin (PEG-LD, Duomeisu) has a reduced cardiac toxicity. This phase I study aimed to investigate the maximum tolerated doses (MTDs) and dose-limiting toxicities (DLTs) of the PEG-LD and cisplatin combination in patients with metastatic and recurrent osteosarcoma.

METHODS

Patients were given PEG-LD at a dose of 40, 50, or 60 mg/m² on day 1 of each 21-day cycle, according to a 3 + 3 approach for dose escalation. Cisplatin was administered as a fixed dose of 100 mg/m² for every cycle. Toxicities and tumor response were observed.

RESULTS

A total of 15 patients were enrolled in this trial, and nine of the patients had received prior doxorubicin. The MTD of PEG-LD was reached at 50 mg/m² in this regimen, with neutropenic fever and stomatitis as DTLs. The main adverse event (AE) was myelosuppression. The most common non-hematological AEs were vomiting, hypoproteinemia, stomatitis and transient sinus arrhythmia. Grade 3-4 toxicity was neutropenia, leukopenia, thrombocytopenia, anemia and stomatitis in the whole cohort. All the AEs were relieved after symptomatic and supportive treatment. Totally, the overall response rate was 13.3% and disease control rate was 66.7%. For the six patients who have not received prior doxorubicin, one partial response and five stable diseases were observed.

CONCLUSION

We provide the data showing that PEG-LD 50 mg/m² combined with cisplatin 100 mg/m² demonstrated an acceptable safety profile and promising clinical activity in advanced osteosarcoma, which merits further evaluation in phase II studies.

TRIAL REGISTRATION

ChiCTR1900021550.

Jacob TJ, Mathew LG, Kurian JJ. Long-Term Outcomes and Prognostic Factors Affecting Survival after Pulmonary Metastasectomy in Solid Tumors of Childhood: A Single Center Experience

Introduction

This study assessed the long-term survival and the prognostic variables affecting survival following pulmonary metastasectomy (PM) secondary to childhood solid tumors.

Materials and Methods

A retrospective analysis was done on 22 children who underwent PM for solid tumors between January 2007 and February 2020. The overall survival (OS) and event-free survival (EFS) at the end of the study period were noted. Tumor histology, completeness of resection, disease-free interval, laterality, location, number, and size of lung nodules were assessed for their significance in contributing to survival.

Results

High-grade osteosarcoma (54.5%), followed by Wilms' tumor (18.2%), was the most common histological types. Unilateral nodules (59.1%) situated in a peripheral, sub-pleural location (91%) were the most common presentation. Pleural extension was noted in 12 (54.5%) patients. Synchronous pulmonary metastases were noted in 12 (54.5%) patients. Two developed metastases while undergoing chemotherapy and eight after the completion of therapy. The EFS and OS were both 31.8% at a median follow-up of 15.5 months (range 3-129 months). The median time required for an event to occur was 4 months (95% confidence interval [CI]: 1.4, 6.6 months) and median post-PM survival interval was 17 months (95% CI: 6.6, 27.4 months). Significant association was noted between preoperative tumor response to chemotherapy (P = 0.002) and survival.

Conclusion

PM can improve survival in a select group of children with metastatic solid tumors. Favorable tumor response to chemotherapy was found to be a significant prognostic factors influencing survival.

Treatment of 120 adult osteosarcoma patients with metachronous and synchronous metastases: A retrospective series of the French Sarcoma Group

Treatment options for metastatic osteosarcomas are scarce. Following failure of standard first line therapy, patients who relapse present a challenging treatment dilemma, and have a poor prognosis. Surgical removal of all metastases is essential. A retrospective analysis of patients with metastatic osteosarcomas was conducted in 15 French Sarcoma Group centers. From January 2009 to December 2018, we identified 120 adult patients; 36 with synchronous and 84 with metachronous metastases with 74 males and 46 females. Mean age was 30 years (18-53). Metastatic sites were lung, bone and other in 91, 11 and 24 patients, respectively. Mean time to first metachronous metastases was 22 months (4-97). All patients except 13 (10.8%) with metachronous metastases received a first line systemic treatment for relapse, and 39 patients (32.5%) were included in a clinical trial. Eighty-one patients (67.5%) had local treatment of distant metastases. Median progression free survival (PFS) and overall survival (OS) were 5.5 (95% CI 4.6-6.4) and 20.5 months (95% CI 13.2-27.7) respectively for the overall group. In multivariate analysis, more than five metastases, time to first metastases <24 months, were statistically significant negative prognostic factors for OS and PFS (P = .002, ≤.001 and P = .006, ≤.001, respectively). Surgery of metastases was associated with better prognosis on OS and PFS (P = .001 and .037, respectively). The presence of bone metastases was a negative prognostic factor on OS but not on PFS (P = .021). In reference sarcoma centers, relapsed osteosarcoma patients with more than one metastasis commonly receive more than one line of systemic therapy, and are included in clinical trial if available.

State-of-the-art, approved therapeutics for the pharmacological management of osteosarcoma

Introduction: Advances in the treatment of osteosarcoma (OS) came in the mid-1970s, when adding chemotherapy to surgery significantly improved patient survival. OS outcomes have since plateaued, however, despite exhaustive clinical investigations.Area covered: This review focuses on the most significant recent results of trials (in phases II and III) on localized and metastatic/relapsing OS and offers an overview of new targeted drugs.Expert opinion: Recent findings confirm the MAP (methotrexate, doxorubicin, and cisplatin) regimen as the gold standard for OS patients, also in metastatic cases, and the inefficacy of augmenting or modifying chemotherapy in poor responder patients. Immunotherapy and several tyrosine kinase inhibitors seem to be effective and promising in the treatment of OS. Optimizing the use of active drugs available by personalizing chemotherapies might prove important in the future. We urgently need bench-to-bedside research on OS. This will need to involve the extensive sequencing and immunoprofiling of all resected tumor tissue to find new therapeutic agents, especially for relapsing/metastatic patients. The low incidence of OS, its genomic complexity, and differences within and between tumors combine to complicate efforts to elucidate the biology of this disease. This means that we need to pool the resources of different groups studying OS and support translational research.

Targeting the VEGF Pathway in Osteosarcoma

Osteosarcoma is the most common primary tumor of the bones affecting mainly young adults. Despite the advances in the field of systemic anticancer therapy, the prognosis of relapsed of metastatic osteosarcoma patients remain dismal with very short survival. However, the better understanding of the pathophysiology of this subtype of sarcoma has led to the identification of new targeted agents with significant activity. In fact, increased angiogenesis plays a major role in the tumor growth and survival of osteosarcoma patients. Several targeted agents have demonstrated a significant anti-tumor activity including multi-kinase inhibitors. In this review, we will discuss the pathophysiology, rationale, and role of targeting angiogenesis via the VEGF pathway in patients with osteosarcoma with emphasis on the published clinical trials and future directions.

Successive Osteosarcoma Relapses after the First Line O2006/Sarcome-09 Trial: What Can We Learn for Further Phase-II Trials?

Simple Summary

Osteosarcoma is the most common primary malignant bone tumour in adolescents and young adults. The survival of osteosarcoma patients has not improved for four decades. The purpose was to describe first and subsequent relapses in patients from the OS2006/Sarcome-09 trial, to help future trial design. Among the 434 patients with a confirmed osteosarcoma who achieved CR1 during first line treatment, 157 patients experienced at least one relapse. The 3-year progression-free and overall survival rates were 21% and 37%, respectively. Only a quarter of the patients were included in clinical trials at first recurrence. We want to promote randomised phase-II trials in osteosarcoma relapses, with broad inclusion criteria at study entry in terms of age and disease status, and PFS as primary endpoint. Surgery/local treatment of all residual lesions should be allowed when feasible. Single-arm trial design could be used for subsequent relapses.

Abstract

The purpose was to describe first and subsequent relapses in patients from the OS2006/Sarcome-09 trial, to help future trial design. We prospectively collected and analysed relapse data of all French patients included in the OS2006/Sarcome-09 trial, who had achieved a first complete remission. 157 patients experienced a first relapse. The median interval from diagnosis to relapse was 1.7 year (range 0.5–7.6). The first relapse was metastatic in 83% of patients, and disease was not measurable according to RECIST 1.1 criteria in 23%. Treatment consisted in systemic therapy (74%) and surgical resection (68%). A quarter of the patients were accrued in a phase-II clinical trial. A second complete remission was obtained for 79 patients. Most of them had undergone surgery (76/79). The 3-year progression-free and overall survival rates were 21% and 37%, respectively. In patients who achieved CR2, the 3y-PFS and OS rates were 39% and 62% respectively. Individual correlation between subsequent PFS durations was poor. For osteosarcoma relapses, we recommend randomised phase-II trials, open to patients from all age categories (children, adolescents, adults), not limited to patients with measurable disease (but stratified according to disease status), with PFS as primary endpoint, response rate and surgical CR as secondary endpoints.

How Are Indeterminate Pulmonary Nodules at Diagnosis Associated with Survival in Patients with High-Grade Osteosarcoma?

BACKGROUND

Pulmonary metastases are a poor prognostic factor in patients with osteosarcoma; however, the clinical significance of subcentimeter lung nodules and whether they represent a tumor is not fully known. Because the clinician is faced with decisions regarding biopsy, resection, or observation of lung nodules and the potential impact they have on decisions about resection of the primary tumor, this remains an area of uncertainty in patient treatment. Surgical management of the primary tumor is tailored to prognosis, and it is unclear how aggressively patients with indeterminate pulmonary nodules (IPNs), defined as nodules smaller than 1 cm at presentation, should be treated. There is a clear need to better understand the clinical importance of these nodules.

QUESTIONS/PURPOSES

(1) What percentage of patients with high-grade osteosarcoma and spindle cell sarcoma of bone have IPNs at diagnosis? (2) Are IPNs at diagnosis associated with worse metastasis-free and overall survival? (3) Are there any clinical or radiologic factors associated with worse overall survival in patients with IPN?

METHODS

Between 2008 and 2016, 484 patients with a first presentation of osteosarcoma or spindle cell sarcoma of bone were retrospectively identified from an institutional database. Patients with the following were excluded: treatment at another institution (6%, 27 of 484), death related to complications of neoadjuvant chemotherapy (1%, 3 of 484), Grade 1 or 2 on final pathology (4%, 21 of 484) and lack of staging chest CT available for review (0.4%, 2 of 484). All patients with abnormalities on their staging chest CT underwent imaging re-review by a senior radiology consultant and were divided into three groups for comparison: no metastases (70%, 302 of 431), IPN (16%, 68 of 431), and metastases (14%, 61 of 431) at the time of diagnosis. A random subset of CT scans was reviewed by a senior radiology registrar and there was very good agreement between the two reviewers (κ = 0.88). Demographic and oncologic variables as well as treatment details and clinical course were gleaned from a longitudinally maintained institutional database. The three groups did not differ with regard to age, gender, subtype, presence of pathological fracture, tumor site, or chemotherapy-induced necrosis. They differed according to local control strategy and tumor size, with a larger proportion of patients in the metastases group presenting with larger tumor size and undergoing nonoperative treatment. There was no differential loss to follow-up among the three groups. Two percent (6 of 302) of patients with no metastases, no patients with IPN, and 2% (1 of 61) of patients with metastases were lost to follow-up at 1 year postdiagnosis but were not known to have died. Individual treatment decisions were determined as part of a multidisciplinary conference, but in general, patients without obvious metastases received (neo)adjuvant chemotherapy and surgical resection for local control. Patients in the no metastases and IPN groups did not differ in local control strategy. For patients in the IPN group, staging CT images were inspected for IPN characteristics including number, distribution, size, location, presence of mineralization, and shape. Subsequent chest CT images were examined by the same radiologist to reevaluate known nodules for interval change in size and to identify the presence of new nodules. A random subset of chest CT scans were re-reviewed by a senior radiology resident (κ = 0.62). The association of demographic and oncologic variables with metastasis-free and overall survival was first explored using the Kaplan-Meier method (log-rank test) in univariable analyses. All variables that were statistically significant (p < 0.05) in univariable analyses were entered into Cox regression multivariable analyses.

RESULTS

Following re-review of staging chest CTs, IPNs were found in 16% (68 of 431) of patients, while an additional 14% (61 of 431) of patients had lung metastases (parenchymal nodules 10 mm or larger). After controlling for potential confounding variables like local control strategy, tumor size, and chemotherapy-induced necrosis, we found that the presence of an IPN was associated with worse overall survival and a higher incidence of metastases (hazard ratio 1.9 [95% CI 1.3 to 2.8]; p = 0.001 and HR 3.6 [95% CI 2.5 to 5.2]; p < 0.001, respectively). Two-year overall survival for patients with no metastases, IPN, or metastases was 83% [95% CI 78 to 87], 65% [95% CI 52 to 75] and 45% [95% CI 32 to 57], respectively (p = 0.001). In 74% (50 of 68) of patients with IPNs, it became apparent that they were true metastatic lesions at a median of 5.3 months. Eighty-six percent (43 of 50) of these patients had disease progression by 2 years after diagnosis. In multivariable analysis, local control strategy and tumor subtype correlated with overall survival for patients with IPNs. Patients who were treated nonoperatively and who had a secondary sarcoma had worse outcomes (HR 3.6 [95% CI 1.5 to 8.3]; p = 0.003 and HR 3.4 [95% CI 1.1 to 10.0]; p = 0.03). The presence of nodule mineralization was associated with improved overall survival in the univariable analysis (87% [95% CI 39 to 98] versus 57% [95% CI 43 to 69]; p = 0.008), however, because we could not control for other factors in a multivariable analysis, the relationship between mineralization and survival could not be determined. We were unable to detect an association between any other nodule radiologic features and survival.

CONCLUSION

The findings show that the presence of IPNs at diagnosis is associated with poorer survival of affected patients compared with those with normal staging chest CTs. IPNs noted at presentation in patients with high-grade osteosarcoma and spindle cell sarcoma of bone should be discussed with the patient and be considered when making treatment decisions. Further work is required to elucidate how the nodules should be managed.

LEVEL OF EVIDENCE

Level III, prognostic study.

Targetable Intercellular Signaling Pathways Facilitate Lung Colonization in Osteosarcoma

Outcomes for young people diagnosed with osteosarcoma hinge almost exclusively on whether they develop lung metastasis. The striking predilection that osteosarcoma shows for metastatic spread to lung suggests properties and/or lung interactions that generate tissue-specific survival and proliferation advantages. While these mechanisms remain overall poorly defined, studies have begun to describe biological elements important to metastasis. Mechanisms described to date include both cell-autonomous adaptations that allow disseminated tumor cells to survive the stressors imposed by metastasis and intercellular signaling networks that tumor cells exploit to pirate needed signals from surrounding tissues or to recruit other cells that create a more favorable niche. Evidence suggests that cell-autonomous changes are largely driven by epigenetic reprogramming of disseminated tumor cells that facilitates resistance to late apoptosis, manages endoplasmic reticulum (ER) stressors, promotes translation of complex transcripts, and activates clotting pathways. Tumor-host signaling pathways important for lung colonization drive interactions with lung epithelium, mesenchymal stem cells, and mediators of innate and adaptive immunity. In this chapter, we highlight one particular pathway that integrates cell-autonomous adaptations with lung-specific tumor-host interactions. In this mechanism, aberrant ΔNp63 expression primes tumor cells to produce IL6 and CXCL8 upon interaction with lung epithelial cells. This tumor-derived IL6 and CXCL8 then initiates autocrine, osteosarcoma-lung paracrine, and osteosarcoma-immune paracrine interactions that facilitate metastasis. Importantly, many of these pathways appear targetable with clinically feasible therapeutics. Ongoing work to better understand metastasis is driving efforts to improve outcomes by targeting the most devastating complication of this disease.

Survival after pulmonary metastasectomy for relapsed osteosarcoma

OBJECTIVES

The purpose of this study was to evaluate the postrelapse survival of relapsed osteosarcoma with pulmonary metastases in patients who received pulmonary metastasectomy using intent to treat and propensity score analysis.

METHODS

Patients with osteosarcoma who relapsed with pulmonary metastases between 2004 and 2018 who were treated in a hospital affiliated with a medical school were included. All the enrolled patients were evaluated as operable with assessment algorithm at the time of diagnosis of pulmonary relapse and intent to treat analysis was done. Multiple propensity score methods (eg, matching, stratification, covariate adjustment, and inverse probability of treatment weighting) were performed to balance confounding bias. Cox proportional hazards regression and the Kaplan-Meier method were used to evaluate patient survival.

RESULTS

A total of 125 patients met the study criteria. Of these, 59 (47.2%) patients received pulmonary metastasectomy combined with chemotherapy and 66 (52.8%) received chemotherapy alone. The 2-year and 5-year postrelapse survival rate of metastasectomy group and nonmetastasectomy group were 68.4% versus 25.0% and 41.0% versus 0%, respectively. The median postrelapse survival was 24.9 versus 13.5 months, respectively. Pulmonary metastasectomy was independently associated with improved survival (hazard ratio, 0.185; 95% confidence interval, 0.103-0.330; P < .001). These results were confirmed by multiple propensity score analyses. Further stratified analysis revealed that the survival advantage associated with metastasectomy was not significant in patients with metastases involving ≥3 lung lobes and patients with very high pretreatment serum alkaline phosphatase (more than twice the upper limit).

CONCLUSIONS

Pulmonary metastasectomy is associated with improved survival in patients with recurrent osteosarcoma.

A multi-institutional phase 2 trial of stereotactic body radiotherapy in the treatment of bone metastases in pediatric and young adult patients with sarcoma

BACKGROUND

Metastasectomy is standard of care for pediatric patients with metastatic sarcoma with limited disease. For patients with unresectable disease, stereotactic body radiotherapy (SBRT) may serve as an alternative. Herein, the authors report the results of a prospective, multi-institutional phase 2 trial of SBRT in children and young adults with metastatic sarcoma.

METHODS

Patients aged >3 years and ≤40 years with unresected, osseous metastatic nonrhabdomyosarcoma sarcomas of soft tissue and bone were eligible. Patients received SBRT to a dose of 40 Gray (Gy) in 5 fractions. Local control (LC), progression-free survival (PFS), and overall survival (OS) were calculated using the Kaplan-Meier method.

RESULTS

Fourteen patients with a median age of 17 years (range, 4-25 years) were treated to 37 distinct metastatic lesions. With a median follow-up of 6.8 months (30.5 months in surviving patients), the Kaplan-Meier patient-specific and lesion-specific LC rates at 6 months were 89% and 95%, respectively. The median PFS was 6 months and the median OS was 24 months. In a post hoc analysis, PFS (median, 9.3 months vs 3.7 months; log-rank P = .03) and OS (median not reached vs 12.7 months; log-rank P = .02) were improved when all known sites of metastatic disease were consolidated with SBRT compared with partial consolidation. SBRT was well tolerated, with 2 patients experiencing grade 3 toxicities.

CONCLUSIONS

SBRT achieved high rates of LC in pediatric patients with inoperable metastatic nonrhabdomyosarcoma sarcomas of soft tissue and bone. These results suggest that the ability to achieve total consolidation of metastatic disease with SBRT is associated with improved PFS and OS.

Implication of ZNF217 in Accelerating Tumor Development and Therapeutically Targeting ZNF217-Induced PI3K-AKT Signaling for the Treatment of Metastatic Osteosarcoma

We previously identified ZNF217 as an oncogenic driver of a subset of osteosarcomas using the Sleeping Beauty (SB) transposon system. Here, we followed up by investigating the genetic role of ZNF217 in osteosarcoma initiation and progression through the establishment of a novel genetically engineered mouse model, in vitro assays, orthotopic mouse studies, and paired these findings with preclinical studies using a small-molecule inhibitor. Throughout, we demonstrate that ZNF217 is coupled to numerous facets of osteosarcoma transformation, including proliferation, cell motility, and anchorage independent growth, and ultimately promoting osteosarcoma growth, progression, and metastasis in part through positive modulation of PI3K-AKT survival signaling. Pharmacologic blockade of AKT signaling with nucleoside analogue triciribine in ZNF217⁺ orthotopically injected osteosarcoma cell lines reduced tumor growth and metastasis. Our data demonstrate that triciribine treatment may be a relevant and efficacious therapeutic strategy for patients with osteosarcoma with ZNF217⁺ and p-AKT rich tumors. With the recent revitalization of triciribine for clinical studies in other solid cancers, our study provides a rationale for further evaluation preclinically with the purpose of clinical evaluation in patients with incurable, ZNF217⁺ osteosarcoma.

Temozolomide and etoposide combination for the treatment of relapsed osteosarcoma

The prognosis of patients with relapsed osteosarcoma is extremely poor and the optimal treatment remains to be identified. Here, we retrospectively analysed the clinical outcomes of nine patients with relapsed osteosarcoma treated with temozolomide/etoposide. Of the two patients who received temozolomide/etoposide as palliative therapy for unresectable tumours, one remained alive with stable disease for >4 years. The remaining seven patients received temozolomide/etoposide as adjuvant therapy following resection of relapsed metastatic disease; of these, one was free from disease for 41 months. Potentially beneficial effects were observed in two of three O6-methylguanine-DNA methyltransferase protein-negative patients, whereas all five O6-methylguanine-DNA methyltransferase-positive patients experienced subsequent relapse. None of the patients experienced severe adverse effects requiring hospitalization. Temozolomide/etoposide is a feasible candidate as salvage therapy for relapsed osteosarcoma. Further studies are needed to verify the utility of O6-methylguanine-DNA methyltransferase protein expression as a biomarker for predicting the response to this treatment.

Thoracoscopy vs thoracotomy for the management of metastatic osteosarcoma: A Pediatric Surgical Oncology Research Collaborative Study

Complete surgical resection of pulmonary metastatic disease in patients with osteosarcoma is crucial to long-term survival. Open thoracotomy allows palpation of nodules not identified on imaging but the impact on survival is unknown. The objective of this study was to compare overall survival (OS) and pulmonary disease-free survival (DFS) in children who underwent thoracotomy vs thoracoscopic surgery for pulmonary metastasectomy. A multi-institutional collaborative group retrospectively reviewed 202 pediatric patients with osteosarcoma who underwent pulmonary metastasectomy by thoracotomy (n = 154) or thoracoscopy (n = 48). Results were analyzed by Kaplan-Meier survival estimates and multivariate Cox proportional hazard regression models. With median follow-up of 45 months, 135 (67.5%) patients had a pulmonary relapse and 95 (47%) patients were deceased. Kaplan-Meier analysis showed no significant difference in 5-year pulmonary DFS (25% vs 38%; P = .18) or OS (49% vs 42%, P = .37) between the surgical approaches of thoracotomy and thoracoscopy. In Cox regression analysis controlling for other factors impacting outcome, there was a significantly increased risk of mortality (HR 2.11; P = .027; 95% CI 1.09-4.09) but not pulmonary recurrence (HR 0.96; P = .90; 95% CI 0.52-1.79) with a thoracoscopic approach. However, in the subset analysis limited to patients with oligometastatic disease, thoracoscopy had no increased risk of mortality (HR 1.16; P = .62; 0.64-2.11). In conclusion, patients with metastatic osteosarcoma and limited pulmonary disease burden demonstrate comparable outcomes after thoracotomy and thoracoscopy for metastasectomy. While significant selection bias in these surgical cohorts limits the generalizability of the conclusions, clinical equipoise for a randomized clinical trial in patients with oligometastatic disease is supported.

What is the best clinical approach to recurrent/refractory osteosarcoma?

Introduction: Osteosarcoma is the most common malignant bone tumor. It is currently treated with pre-and postoperative chemotherapy, associated with surgical resection of the tumor.Area covered: Relapses occur in about one in three patients presenting with localized disease, and three in four of those with metastases at diagnosis. Relapsing disease carries a very poor prognosis, with 5-year survival rates ranging between 13% and 40%.Expert opinion: Patients with unilateral lung involvement or solitary lung metastases and a recurrence-free interval (RFI) longer than 24 months have a better prognosis, and could be managed with surgical resection and close observation. Complete surgical resection of all sites of disease remains essential to survival: patients unable to achieve complete remission have a catastrophic overall survival rate. The role of second-line chemotherapy is not at all clear, and no controlled studies are available on this topic. It is worth considering for patients unable to achieve complete surgical remission, and those with multiple metastases and/or a RFI <24 months. Given their dismal prognosis, patients with multiple sites of disease not amenable to complete surgical resection should also be considered for innovative therapeutic approaches.

Response to Pazopanib in Patients With Relapsed Osteosarcoma

Axial skeleton primary tumor, metastatic disease at presentation, incomplete surgical resection, and <90% tumor necrosis have all been known to influence prognosis adversely in osteosarcoma. Relapse of osteosarcoma, typically occurring within the first 18 months of therapy, with an incidence rate of 50% is treated with surgery, chemotherapy, and targeted therapy. Here, we discuss 2 patients treated with pazopanib, a multi-tyrosine kinase inhibitor presently approved to treat renal cell carcinoma and soft tissue sarcomas. Case 1 achieved positive response and remains on pazopanib. Case 2 sustained gastrointestinal toxicity requiring suspension of drug, despite achieving stable disease.

Phase II, multi-center, open-label, single-arm clinical trial evaluating the efficacy and safety of Mycophenolate Mofetil in patients with high-grade locally advanced or metastatic osteosarcoma (ESMMO): rationale and design of the ESMMO trial

BACKGROUND

Clinical outcomes of patients with osteosarcoma remain unsatisfactory, with little improvement in a 5-year overall survival over the past three decades. There is a substantial need for further research and development to identify and develop more efficacious agents/regimens in order to improve clinical outcomes of patients for whom the prognosis is unfavorable. Recently, mycophenolate mofetil, a prodrug of mycophenolic acid, has been found to have anticancer activity against osteosarcoma in both in vitro and animal experiments, so that further investigation in humans is warranted.

METHODS

A total of 27 patients with high-grade locally advanced or metastatic osteosarcoma will be enrolled into this phase II, multi-center, open-label, single-arm, two-stage clinical trial. The main objectives of this study are to determine the efficacy and safety of mycophenolate mofetil in the patients. The primary endpoint is progression-free survival at 16 weeks; the secondary endpoints include progression-free survival, overall survival, overall response rate, safety parameters, pharmacokinetic parameters, biomarkers, pain score, and quality of life. Mycophenolate mofetil at the initial dose of 5 g/day or lower will be administered for 4 cycles (28 days/cycle) or until disease progression or unacceptable toxicity. The dose of mycophenolate mofetil may be reduced by 1-2 g/day or withheld for some Grade 3 or Grade 4 toxicities whenever clinically needed. The duration of study participation is approximately 4-5 months, with a minimum of 12 study visits. If mycophenolate mofetil proves beneficial to some patients, as evidenced by stable disease or partial response at 16 weeks, administration of mycophenolate mofetil will continue in the extension period.

DISCUSSION

This trial is the first step in the translation of therapeutic potential of mycophenolate mofetil emerging from in vitro and animal studies into the clinical domain. It is designed to assess the efficacy and safety of mycophenolate mofetil in patients with high-grade locally advanced or metastatic osteosarcoma. The results will provide important information about whether or not mycophenolate mofetil is worth further development.

TRIAL REGISTRATION

This trial was prospectively registered on Thai Clinical Trials Registry (registration number: TCTR20190701001). The posted information will be updated as needed to reflect protocol amendments and study progress.

A population-based propensity-matched study of regional dissections in patients with metastatic osteosarcoma

Background

The survival rates of patients with metastatic osteosarcoma are poor, and the prognosis is closely related to the choice of treatment, especially surgery. This study aimed to evaluate the survival outcomes of patients with metastatic osteosarcoma undergoing regional dissections.

Methods

We collected data on patients with metastatic osteosarcoma between 2004 and 2014 from the Surveillance, Epidemiology, and End Results (SEER) database. Kaplan–Meier curves were used to compare overall survival (OS) and cancer-specific survival (CSS), while univariate and multivariate Cox regression analyses were used to evaluate outcomes. Propensity score matching (PSM) was used to minimize the effects of confounding factors.

Results

The SEER database had records of 2768 patients diagnosed with osteosarcoma, of whom 398 were included in our study. Of the included patients, 116 (29.15%) underwent regional dissections, while 282 (70.85%) underwent non-regional dissections. The univariate and multivariate Cox regression analyses, prior to PSM, showed that OS (hazard ratio (HR): 0.34, 95% confidence interval (CI): 0.26–0.44, P<0.001 and HR: 0.47, 95% CI: 0.35–0.64, P<0.001, respectively) and CSS (HR: 0.33, 95% CI: 0.25–0.43, P<0.001 and HR: 0.46, 95% CI: 0.34–0.63, P<0.001, respectively) were better in patients who underwent regional dissections than those who underwent non-regional dissections. Compared with non-regional dissections, regional dissections, which included both primary tumour resection (PTR) and primary tumour and metastatic site resection (PTMR), were associated with better OS (P<0.001) and CSS (P<0.001) . However, the survival outcomes following PTR and PTMR showed no significant difference. After PSM, patients in the regional dissection group still had a higher OS (P<0.001) and CSS (P<0.001) than those in the non-regional dissection group.

Conclusions

Compared with non-regional dissection, regional dissection resulted in better survival in patients with metastatic osteosarcoma.

Cabozantinib in patients with advanced Ewing sarcoma or osteosarcoma (CABONE): a multicentre, single-arm, phase 2 trial

BACKGROUND

Patients with Ewing sarcoma or osteosarcoma have a median overall survival of less than 12 months after diagnosis, and a standard treatment strategy has not yet been established. Pharmacological inhibition of MET signalling and aberrant angiogenesis has shown promising results in several preclinical models of Ewing sarcoma and osteosarcoma. We aimed to investigate the activity of cabozantinib, an inhibitor of MET and VEGFR2, in patients with advanced Ewing sarcoma and osteosarcoma.

METHODS

We did a multicentre, single-arm, two-stage, phase 2 trial in patients with advanced Ewing sarcoma or osteosarcoma recruited from ten centres in the French Sarcoma Group. Key eligibility criteria were aged 12 years or older, Eastern Cooperative Oncology Group performance status of 0-1, and documented disease progression (according to Response Evaluation Criteria in Solid Tumors version 1.1) before study entry. The number of previous lines of treatment was not limited. Patients received cabozantinib (adults 60 mg, children [<16 years] 40 mg/m²) orally once daily in 28-day cycles until disease progression, unacceptable toxicity, the investigator's decision to discontinue, or participant withdrawal. The primary endpoint for Ewing sarcoma was best objective response within 6 months of treatment onset; for osteosarcoma, a dual primary endpoint of 6-month objective response and 6-month non-progression was assessed. All enrolled patients who received at least one dose of cabozantinib were included in the safety analysis, and all participants who received at least one complete or two incomplete treatment cycles were included in the efficacy population. This study was registered with ClinicalTrials.gov, number NCT02243605.

FINDINGS

Between April 16, 2015, and July 12, 2018, 90 patients (45 with Ewing sarcoma 45 with osteosarcoma) were recruited to the study. Median follow-up was 31·3 months (95% CI 12·4-35·4) for patients with Ewing sarcoma and 31·1 months (24·4-31·7) for patients with osteosarcoma. 39 (87%) patients with Ewing sarcoma and 42 (93%) patients with osteosarcoma were assessable for efficacy after histological and radiological review. In patients with Ewing sarcoma, ten (26%; 95% CI 13-42) of 39 patients had an objective response (all partial responses) by 6 months; in patients with osteosarcoma, five (12%; 4-26) of 42 patients had an objective response (all partial responses) and 14 (33%; 20-50) had 6-month non-progression. The most common grade 3 or 4 adverse events were hypophosphataemia (five [11%] for Ewing sarcoma, three [7%] for osteosarcoma), aspartate aminotransferase increase (two [4%] for Ewing sarcoma, three [7%] for osteosarcoma), palmar-plantar syndrome (three [7%] for Ewing sarcoma, two [4%] for osteosarcoma), pneumothorax (one [2%] for Ewing sarcoma, four [9%] for osteosarcoma), and neutropenia (two [4%] for Ewing sarcoma, four [9%] for osteosarcoma). At least one serious adverse event was reported in 61 (68%) of 90 patients. No patients died from drug-related toxic effects.

INTERPRETATION

Cabozantinib has antitumor activity in patients with advanced Ewing sarcoma and osteosarcoma and was generally well tolerated. Cabozantinib could represent a new therapeutic option in this setting, and deserves further investigation.

FUNDING

Institut Bergonié; French National Cancer Institute; Association pour la Recherche contre le Cancer.

A multicentric randomized phase II clinical trial evaluating high-dose thiotepa as adjuvant treatment to standard chemotherapy in patients with resectable relapsed osteosarcoma

BACKGROUND

The role of high-dose chemotherapy in relapsing osteosarcomas has not been established. We evaluated the efficacy and tolerance of high-dose thiotepa (HDTp) after standard chemotherapy (SCT) in patients with relapsed osteosarcoma.

PATIENTS AND METHODS

This randomised open-label phase II study enrolled patients 1-50 years, with local or metastatic relapse of a high-grade osteosarcoma, not progressive after two cycles of SCT, for whom a complete surgery can be achievable following treatment. The trial assigned enrolled patients in a 1:1 ratio to receive two additional courses of SCT + HDTp and autologous transplantation (Arm A), or SCT alone (Arm B). Surgery for complete resection was scheduled as soon as feasible. Primary endpoint was overall survival (OS). Secondary objectives included progression-free survival (PFS) and safety.

RESULTS

From September 2009 to November 2016, 44 patients were randomised (A:22; B:22). In total, 54.5% were males, and the median age was 16 years (9-32years). The two-year OS rate was 66.7% (95% CI 42.5-82.5) (SCT + HDTp, Arm A) versus 50.0% (95% CI 28.2-68.4) for SCT alone (Arm B). Median OS was 27.4 and 24.8 months, respectively (hazard ratio [HR] 0.826, 95% CI 0.393-1.734; p = 0.6123). Median PFS was 15.6 (8.9-24.9) months in Arm A versus 7.2 (4.8-33.3) months in Arm B, p = 0.3845. Among the 22 patients treated with SCT + HDTp, 16 (72.7%) experienced at least one grade ≥3 adverse events versus 18/22 (81.8%) patients treated with SCT. No toxic death occurred.

CONCLUSION

Adjuvant HDTp failed to significantly improve OS and PFS in resectable relapsed osteosarcomas. Despite a trend of prolonged survival and an acceptable toxicity, thiotepa cannot be recommended.

KEY MESSAGE

HDTp and autologous transplantation added to SCT did not improve OS and PFS in patients with resectable relapsed osteosarcomas. Despite a trend of prolonged survival, thiotepa cannot be recommended.

Lung metastases at the initial diagnosis of high-grade osteosarcoma: prevalence, risk factors and prognostic factors. A large population-based cohort study

BACKGROUND

Osteosarcoma is the most prevalent malignant bone tumor in children and adolescents. Lung metastases are associated with poor prognosis.

OBJECTIVE

The aim here was to explore the prevalence of and risk and prognostic factors for lung metastases in high-grade osteosarcoma patients.

DESIGN AND SETTING

Retrospective cohort study based on the Surveillance, Epidemiology and End Results (SEER) database in the United States.

METHODS

Data on 1,408 high-grade osteosarcoma patients registered in the SEER database between 2010 and 2015 were extracted. From these, all patients with high-grade osteosarcoma and initial lung metastasis were selected for analysis on risk and prognostic factors for lung metastases. Overall survival was estimated.

RESULTS

There were 238 patients (16.90%) with lung metastases at diagnosis. Axial location, tumor size > 10 cm (odds ratio, OR 3.19; 95% confidence interval, CI: 1.58-6.45), higher N stage (OR 4.84; 95% CI: 1.94-12.13) and presence of bone metastases (OR 8.73; 95% CI: 4.37-17.48) or brain metastases (OR 25.63; 95% CI: 1.55-422.86) were significantly associated with lung metastases. Younger age and surgical treatment (hazard ratio, HR 0.46; 95% CI: 0.30-0.71) favored survival. Median survival was prolonged through primary tumor surgery.

CONCLUSIONS

The factors revealed here may guide lung metastasis screening and prophylactic treatment for osteosarcoma patients. A primary tumor in an axial location, greater primary tumor size, higher lymph node stage and presence of bone or brain metastases were significantly correlated with lung metastases. The elderly group (≥ 60 years) showed significant correlation with poor overall survival. For improved survival among high-grade osteosarcoma patients with lung metastases, aggressive surgery on the primary tumor site should be encouraged.

Programmed cell death 1 (PD-1) targeting in patients with advanced osteosarcomas: results from the PEMBROSARC study

PURPOSE

There are some lines of evidence suggesting a potential role of immunotherapy for treating patients with osteosarcomas.

PATIENTS AND METHODS

This was an open-label, multicentre, phase 2 study of pembrolizumab in combination with metronomic cyclophosphamide in patients with advanced osteosarcomas. All patients received 50 mg b.i.d. of cyclophosphamide one week on and one week off and 200 mg of intravenous pembrolizumab (every 3 weeks). There was a dual primary end-point, encompassing both the non-progression and objective responses at 6 months per Response Evaluation Criteria in Solid Tumours (RECIST), version 1.1. An objective response rate of 20% and/or a 6-month non-progression rate of 60% were determined as reasonable objectives for treatment with meaningful effect. Correlative studies of immune biomarkers were planned from the patients' tumour samples.

RESULTS

Between October 13 2015 and July 3 2017, 17 patients were included. Fifty were assessable for the efficacy end-point. Four patients experienced tumour shrinkage, resulting in a partial response (PR) in one patient (6.7%). The 6-month non-progression rate was 13.3% (95% confidence interval [CI]: 1.7-40.5). The most frequent adverse events were grade I or II nausea, anaemia, anorexia and fatigue. programmed death-ligand 1 (PD-L1) expression rate was low, observed in only 2 cases of 14 with available tumour material. The only patient who experienced PR had a PD-L1-negative tumour.

CONCLUSION

Programmed cell death 1 (PD-1) inhibition has limited activity in osteosarcomas. Further studies investigating PD-1 inhibitor in combination with agents modulating the microenvironment are warranted.

TRIAL REGISTRATION

This study is registered with ClinicalTrials.gov, number NCT02406781.

Furowanin A Exhibits Antiproliferative and Pro-Apoptotic Activities by Targeting Sphingosine Kinase 1 in Osteosarcoma

Osteosarcoma (OS) is one of the most common malignant bone tumors among children and young adults. Furowanin A (Fur A), one of the active ingredients of Millettia pachycarpa Benth, has been found to exert pro-apoptotic activity in human leukemia cells. This study is designed to evaluate the efficacy of Fur A against OS. The effect of Fur A on cell viability was assessed by Cell Counting Kit-8 (CCK-8) assay. Western blotting and quantitative real-time PCR (qRT-PCR) were performed to determine the protein and mRNA level of sphingosine kinase 1 (SphK1), respectively. To validate the role of SphK1 in the pro-apoptotic activity of Fur A, overexpressing SphK1 vector and siRNA targeting SphK1 were utilized to transfect OS cells. Moreover, an OS xenograft murine model was used to analyze the therapeutic efficacy of Fur A in vivo. Fur A treatment led to a dose-dependent decrease in the number of viable cells. It also exhibited antiproliferative activity and significantly promoted apoptotic cell death in OS cell lines. Our results showed that the anticancer activity of Fur A was associated with downregulation of SphK1 and inactivation of its downstream signaling. The mediatory role of SphK1 was validated when the pro-apoptotic activity of Fur A was significantly blocked by SphK1 overexpression, while SphK1 knockdown sensitized the OS cells to Fur A. We concluded that Fur A can exhibit anti-growth and pro-apoptotic activities in vitro and in vivo in OS by downregulating SphK1. Our study highlights the possibility of utilizing Fur A as a chemotherapeutic agent in the treatment of OS. Anat Rec, 302:1941-1949, 2019. © 2019 American Association for Anatomy.

Targeting mutant TP53 as a potential therapeutic strategy for the treatment of osteosarcoma

Mutant TP53 is a promising therapeutic target in cancers. Considering the current challenges facing the clinical treatment of cancer, as well as the urgent need to identify novel therapeutic targets in osteosarcomas, we aimed to evaluate the clinical significance of mutant TP53 in osteosarcoma patients and to explore the therapeutic effect of targeting mutant TP53 in osteosarcomas. We performed a meta-analysis to investigate the relationship between mutant TP53 and the overall survival of patients with osteosarcoma. A CRISPR-Cas9 system and a TP53 inhibitor, NSC59984, were also used to specifically knock-out and inhibit mutant TP53 in the human osteosarcoma cell lines, KHOS, and KHOSR2. The meta-analysis demonstrated that mutations in the TP53 gene could be used to predict a poor 2-year survival in osteosarcoma patients. We also demonstrated that the expression of mutant TP53 in human osteosarcoma cell lines can be efficiently knocked-out using CRISPR-Cas9, and this decreased the proliferation, migration, and tumor formation activity of these osteosarcoma cells. Moreover, drug sensitivity to doxorubicin was increased in these TP53 knock-out osteosarcoma cells. NSC59984 also showed similar anti-tumor effects as CRISPR-Cas9 targeted TP53 in the osteosarcoma cells in vitro. We have also demonstrated that the knock-out or inhibition of mutant TP53 decreased the expression of the oncogene IGF-1R, anti-apoptotic proteins Bcl-2, and Survivin in osteosarcoma cells. Collectively, these results suggest that mutant TP53 is a promising therapeutic target in osteosarcomas. Therefore, further studies exploring novel strategies to target mutant TP53 may help improve the treatment outcomes of osteosarcoma patients in the clinic. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Pulmonary Metastasectomy in Pediatric Solid Tumors

Metastatic disease and the complications of treating metastatic disease are the primary causes of mortality in children with solid malignancies. Nearly 25% of children with solid tumors have metastatic disease at initial diagnosis and another 20% develop metastases during or after treatment. The most common location of these metastases is the lung. The role of surgery in metastatic disease depends greatly on the histology of the primary. In general, tumors that are refractory to adjuvant therapies are most appropriate for pulmonary metastasectomy. This article will summarize the indications for metastasectomy in pediatric solid tumors and discuss the ongoing debate over the technique of metastasectomy in osteosarcoma.

Factors influencing survival after recurrence in osteosarcoma: A report from the Children's Oncology Group

BACKGROUND

Despite drastic improvement in overall survival for pediatric patients with cancer, those with osteosarcoma have stable rates of survival since the 1980s. This project evaluates the effect of several variables on survival after first recurrence in patients with osteosarcoma.

METHODS

Data from three prospective North American cooperative group trials for newly diagnosed osteosarcoma are included: INT-0133, POG-9754, and AOST0121. The analytic population for this study is all enrolled patients with first event-free survival (EFS) event of relapse. The primary outcome measure for this retrospective analysis was survival after recurrence (SAR).

RESULTS

The analytic population consisted of N = 431 patients. SAR was statistically significantly associated with age at enrollment (<10 years, P = 0.027), presence of metastatic disease at diagnosis (localized, P < 0.0001), site of relapse (combination lung + bone, unfavorable, P = 0.005), and time to first relapse (2+ years, favorable, P < 0.0001) in multivariate analysis. Ethnicity, primary site of tumor, race, and sex were not significantly related to SAR.

CONCLUSIONS

Prolonged SAR in patients with relapsed osteosarcoma is associated with age, extent of disease at diagnosis, site of and time to relapse. Adolescent and young adult patients with osteosarcoma have shorter SAR than younger patients, consistent with studies showing decreased overall survival in this group. Although patients with primary metastatic disease have shorter SAR, there is a subset of patients who relapse greater than 2 years from initial diagnosis that will become survivors. Histological response was significantly associated with time to relapse, but was not predictive of SAR.

Combination of gemcitabine and docetaxel: a regimen overestimated in refractory metastatic osteosarcoma?

Background

The combination of gemcitabine and docetaxel (GT) has been demonstrated to be effective against various types of solid tumors, including sarcoma. However, the regimen has not been confirmed in large, well-designed clinical trials in refractory metastatic osteosarcoma.

Methods

We retrospectively reviewed the records of patients with refractory metastatic osteosarcoma at Peking University People’s Hospital who were treated with gemcitabine (1000 mg/m²) intravenously (IV) on Day 1 and Day 8, and docetaxel (75 mg/m²) IV on Day 8, repeated every 21 days.

Results

A total of 52 patients with a median age of 18.4 years were treated with GT at the Peking University People’s Hospital from August 2012 to August 2017. A total of 174 courses were administered. Only five patients with pulmonary metastasis achieved a best response of stable disease (SD), while all other patients had progressive disease. The result was disappointing with an ORR of 0%, a DCR of 9.6%, and a median DOR of 3.5 months. Grade 3 or 4 toxicities were observed in 69 (39.7%) courses and in 28 (53.8%) patients, most of which were myelosuppression, especially thrombocytopenia. No fatal adverse effect (AE) was found.

Conclusion

The combination of gemcitabine and docetaxel (GT) as a salvage regimen is well-tolerated but not as effective as expected in refractory metastatic osteosarcoma. This report highlights the need for the development of new approaches with higher activity in these patients.

Current status of immunotherapy for sarcomas

Although the development of anticancer drugs has improved the outcomes of bone and soft tissue sarcomas, the clinical outcome of patients with relapsed sarcomas remains unsatisfactory due to therapeutic toxicities and resistance to anticancer drugs. Therefore, novel therapeutic modalities are needed to improve the outcome of patients with bone and soft tissue sarcomas. Dendritic cells present tumor antigens and stimulate immune responses, and immune cells, such as cytotoxic T lymphocytes, kill tumor cells by recognizing tumor antigens. However, immune-suppressive conditions by immune regulator PD-1, CTLA-4 and regulatory T cells help tumor growth and progression. In this report, current immunotherapies including cellular immunotherapy and checkpoint inhibitors are introduced, and the advantages and disadvantages of the treatments are discussed.

Mechanisms of oxidative stress, apoptosis, and autophagy involved in graphene oxide nanomaterial anti-osteosarcoma effect

Background

Graphene and its derivative graphene oxide (GO) have been implicated in a wide range of anticancer effects.

Purpose

The objective of this study was to systematically evaluate the toxicity and underlying mechanisms of GO on two osteosarcoma (OSA) cancer cell lines, MG-63 and K₇M₂ cells.

Methods

MG-63 and K₇M₂ cells were treated by GO (0–50 µg/mL) for various time periods. Cell viability was tested by MTT and Live/Dead assays. A ROS Detection Kit based on DHE oxidative reaction was used for ROS detection. An Annexin V-FITC Apoptosis Kit was used for apoptosis detection. Dansylcadaverine (MDC) dyeing was applied for seeking unspecific autophagosomes. Western blot and Immunofluorescence analysis were used for related protein expression and location.

Results

K₇M₂ cells were more sensitive to GO compared with MG-63 cells. The mechanism was attributed to the different extent of the generation of reactive oxygen species (ROS). In K₇M₂ cells, ROS was easily stimulated and the apoptosis pathway was subsequently activated, accompanied by elevated expression of proapoptosis proteins (such as caspase-3) and decreased expression levels of antiapoptosis proteins (such as Bcl-2). A ROS inhibitor (N-acetylcysteine) could alleviate the cytotoxic effects of GO in K₇M₂ cells. However, the production of ROS in MG-63 cells was probably inhibited by the activation of an antioxidative factor, nuclear factor-E2-related factor-2, which translocated from the cytoplasm to the nucleus after GO treatment, while a nuclear factor-E2-related factor-2 inhibitor (ML385) significantly increased ROS production in MG-63 cells when combined with GO treatment. In addition, autophagy was simultaneously stimulated by characteristic autophagosome formation, autophagy flux, and increased the expression level of autophagy-related proteins (such as LC3I to LC3II conversion, ATG5, and ATG7).

Conclusion

This paper proposes various underlying mechanisms of the anticancer effect of GO. The novel synthetic use of GO with an oxidizing agent is the key step for further potential applications in clinical OSA cancer therapy.