Anthracycline-based chemotherapy in extraskeletal myxoid chondrosarcoma: a retrospective study

Extraskeletal Myxoid Chondrosarcoma: Retrospective Case Series Examining Prognostic Factors, Treatment Approaches, and Oncologic Outcomes

OBJECTIVES

Extraskeletal myxoid chondrosarcoma (EMC) is an ultrarare soft tissue sarcoma, and a limited number of studies are published regarding its clinical course and efficacy of treatment. The goal of this retrospective case series is to explore patient characteristics, treatment approaches, and oncologic outcomes to help inform future EMC management.

METHODS

All patients with a diagnosis of EMC seen at the University of Michigan Sarcoma Center between 1998 and 2021 were identified. A chart review was performed to analyze demographics, tumor characteristics, treatments, and outcomes.

RESULTS

Forty-four patients with EMC were identified. The median follow-up was 49.8 months. The median age at diagnosis was 57 (range: 25 to 79), and 35 patients (80%) were male. Thirty-four patients (77%) had locoregional disease at diagnosis, and 26 patients (59%) ultimately developed metastatic disease. After locoregional curative-intent surgery, 15 patients had documented recurrence, of which 11 were metastatic (73%). Five-year overall survival was 79% for all patients, 86% for locoregional disease, and 58% for metastatic disease; for locoregional disease, 5-year disease-free and metastasis-free survival post-surgery were 43% and 53%, respectively; 1-year progression-free survival for metastatic disease from the start of first-line systemic therapy was 43%. Older age was the only factor statistically associated with improved prognosis, although perioperative radiotherapy, lower histologic grade, and negative margins also had directional associations with outcomes.

CONCLUSIONS

The data in this patient series are generally consistent with published literature on EMC and demonstrate a high recurrence rate, high propensity for metastasis, and high rate of progression of metastatic disease on systemic therapy.

Extraskeletal myxoid chondrosarcoma in the pelvis successfully treated with proton beam radiotherapy

The standard treatment for extraskeletal myxoid chondrosarcoma is wide excision. However, extraskeletal myxoid chondrosarcoma is often located in the deep layers of the extremities and pelvis, so functional impairment due to wide resection is unavoidable in many cases. In addition, the efficacy of radiotherapy and chemotherapy has not been defined, so no treatment method is established for unresectable cases. Here we report a case involving a man in his late 60s with extraskeletal myxoid chondrosarcoma of the pelvis who responded to proton beam radiotherapy with intra-arterial chemotherapy and did not require surgery. The patient maintained a complete response for more than 7 years. The findings from this case suggest that definitive irradiation can be an alternative to wide resection for cases of extraskeletal myxoid chondrosarcoma in which severe disability cannot be avoided after resection or when the tumour is inoperable due to its size and location.

Establishment, characterization and functional testing of two novel ex vivo extraskeletal myxoid chondrosarcoma (EMC) cell models

Extraskeletal myxoid chondrosarcoma (EMC) is a malignant mesenchymal neoplasm of uncertain differentiation as classified by the WHO Classification of Tumours 2020. Although often associated with pronlonged survival, EMC has high rates of distant recurrences and disease-associated death. EMCs are translocation sarcomas and harbor in > 90% of the cases an NR4A3 rearrangement. The molecular consequences of the NR4A3 gene fusions are not yet fully elucidated as well-characterized ex vivo cell models for EMC are lacking. Patient-derived ex vivo models are important and essential tools for investigating disease mechanisms associated with diseases that are rare, that exhibit poor prognosis and for the identification of potential novel treatment options. We established two novel EMC ex vivo models (USZ20-EMC1 and USZ22-EMC2) for functional testing and research purposes. USZ20-EMC1 and USZ22-EMC2 were established and maintained as sarco-sphere cell models for several months in culture. The cells were molecularly characterized using DNA sequencing and methylation profiling. Both cell models represent their native tumor tissue as confirmed by histomorphology and their molecular profiles, suggesting that native tumor cell function can be recapitulated in the ex vivo models. Using a functional screening approach, novel anti-cancer drug sensitivities including potential synergistic combinations were identified. In conclusion, two novel EMC ex vivo cell models (USZ20-EMC1 and USZ22-EMC2) were successfully established and characterized from native tumor tissues. Both cell models will be useful tools for further investigating disease mechanisms and for answering basic and translational research questions.

Receptor Tyrosine Kinase Inhibitors for the Treatment of Recurrent and Unresectable Bone Sarcomas

Bone sarcomas are a heterogeneous group of rare tumors with a predominance in the young population. Few options of systemic treatment are available once they become unresectable and resistant to conventional chemotherapy. A better knowledge of the key role that tyrosine kinase receptors (VEGFR, RET, MET, AXL, PDGFR, KIT, FGFR, IGF-1R) may play in the pathogenesis of these tumors has led to the development of multi-target inhibitors (TKIs) that are progressively being incorporated into our therapeutic arsenal. Osteosarcoma (OS) is the most frequent primary bone tumor and several TKIs have demonstrated clinical benefit in phase II clinical trials (cabozantinib, regorafenib, apatinib, sorafenib, and lenvatinib). Although the development of TKIs for other primary bone tumors is less advanced, preclinical data and early trials have begun to show their potential benefit in advanced Ewing sarcoma (ES) and rarer bone tumors (chondrosarcoma, chordoma, giant cell tumor of bone, and undifferentiated pleomorphic sarcoma). Previous reviews have mainly provided information on TKIs for OS and ES. We aim to summarize the existing knowledge regarding the use of TKIs in all bone sarcomas including the most recent studies as well as the potential synergistic effects of their combination with other systemic therapies.

Extraskeletal myxoid chondrosarcoma: Clinicopathological features and outcomes from the United States sarcoma collaborative database

BACKGROUNDS AND OBJECTIVES

This investigation described clinicopathological features and outcomes of extraskeletal myxoid chondrosarcoma (EMC) patients.

METHODS

EMC patients were identified from the United States Sarcoma Collaborative database between 2000 and 2016. Overall survival (OS) and recurrence-free survival (RFS) were calculated, and prognostic factors were analyzed.

RESULTS

Sixty individuals with a mean age of 55 years were included, and 65.0% (n = 39) were male. 73.3% (n = 44) had a primary tumor. A total of 41.6% (n = 25) developed tumor relapse following resection. The locoregional recurrence rate was 30.0% (n = 18/60), and mean follow-up was 42.7 months. The 5-year OS was 71.0%, while the 5-year RFS was 41.4%. On multivariate analysis for all EMC, chemotherapy (hazard ratio [HR], 6.054; 95% confidence interval [CI], 1.33-27.7; p = 0.020) and radiation (HR, 5.07, 95% CI, 1.3-20.1; p = 0.021) were independently predictive of a worse RFS. Among patients with primary EMC only, the 5-year OS was 85.3%, with a 30.0% (n = 12) locoregional recurrence rate, though no significant prognostic factors were identified.

CONCLUSIONS

Long-term survival with EMC is probable, however there exists a high incidence of locoregional recurrence. While chemotherapy and radiation were associated with a worse RFS, these findings were likely confounded by recurrent disease as significance was lost in the primary EMC-only subset.

Primary intracranial extraskeletal myxoid chondrosarcoma: A case report and review of literature

BACKGROUND

Primary intracranial extraskeletal myxoid chondrosarcoma (EMC) is an extremely rare low- to intermediate-grade malignant soft tissue sarcoma, and only 15 cases have been reported in the literature. Due to its rarity, clinical data and research on this tumor type are extremely limited, the pathogenesis and histological origin are still unclear, and the diagnostic and standard clinical treatment strategies for intracranial EMC remain controversial and undefined.

CASE SUMMARY

We reported a case of a 52-year-old male who was admitted to the hospital with headache and dizziness for 1 mo, and his health status deteriorated during the last week. CT of the head showed a well-defined low-density lesion situated in the left cavernous sinus. Brain magnetic resonance imaging (MRI) showed a 3.4 cm × 3.0 cm sized, well-defined, round-shaped and heterogeneously enhanced lesion located in the left cavernous sinus. The entire lesion was removed via supratentorial craniotomy and microsurgery. Postoperative pathological diagnosis indicated primary intracranial EMC. Subsequently, the patient underwent 45 Gy/15 F stereotactic radiotherapy after discharge. At present, it is 12 mo after surgery, with regular postoperative follow-up and regular MRI examinations, that there are no clinical symptoms and radiographic evidence indicating the recurrence of the tumor, and the patient has returned to normal life.

CONCLUSION

Currently, the most beneficial treatment for primary intracranial EMC is gross total resection combined with postoperative radiotherapy. Long-term follow-up is also necessary for patients.

Single-Center Experience with Trabectedin for the Treatment of Non-L-sarcomas

INTRODUCTION

The effectiveness of trabectedin for the treatment of leiomyosarcoma and liposarcoma (commonly referred to as L-sarcomas) has been widely evidenced in clinical trials and real-world studies. Nevertheless, available literature on non-L-sarcomas is less abundant. The objective of the present study is to evaluate the effectiveness and safety of trabectedin in a cohort of patients with non-L-sarcomas in the real-world setting.

METHODS

This retrospective, observational study included 34 patients who received trabectedin in the Hospital de la Santa Creu i Sant Pau (Barcelona, Spain) between October 2013 and July 2020.

RESULTS

The most frequent histologic subtypes were undifferentiated spindle cell/pleomorphic sarcoma (n = 11, 32.4%), synovial sarcoma (n = 6, 17.7%), myxofibrosarcoma (n = 5, 14.7%), and malignant peripheral nerve sheath tumor (n = 4, 11.8%). The mean number of cycles with trabectedin was 5.5 (range 2-28). Three patients achieved partial response (8.8%) and eight patients showed stable disease (23.5%). The objective response rate and disease control rate were 8.8% (95% confidence interval (CI), 95% CI 1.9-23.7) and 32.4% (95% CI 17.4-50.5), respectively. Overall, progression-free survival was 2.9 months (95% CI 2.1-3.4). The overall survival was 7.3 months (95% CI 4.7-12.8). The most common trabectedin-related grade 3 adverse events were observed in 10 patients (26.5%), mostly being neutropenia (14.7%) and elevated transaminases (5.9%), whereas one patient (2.9%) reported grade 4 febrile neutropenia that required hospitalization.

CONCLUSIONS

The findings of this real-life study consistently support that trabectedin is an effective and safe option for the treatment of patients with non-L-sarcoma after failure of anthracyclines and ifosfamide, or in patients who are unsuited to receive these agents.

Uncommon and peculiar soft tissue sarcomas: Multidisciplinary review and practical recommendations. Spanish Group for Sarcoma research (GEIS -GROUP). Part II

Among all Soft Tissue sarcomas there are some subtypes with low incidence and/or peculiar clinical behaviour, that need to be consider separately. Most of them are orphan diseases, whose biological characteristics imply a clearly different diagnostic and therapeutic approach from other more common sarcoma tumors. We present a brief and updated multidiciplinary review, focused on practical issues, aimed at helping clinicians in decision making. In this second part we review these subtypes: Alveolar Soft Part Sarcoma, Epithelioid Sarcoma, Clear Cell Sarcoma, Desmoplastic Small Round Cell Tumor, Rhabdoid Tumor, Phyllodes Tumor, Tenosynovial Giant Cell Tumors, Myoepithelial Tumor, Perivascular Epithelioid Cell Neoplasms (PEComas), Extraskeletal Myxoid Chondrosarcoma, NTRK-fusions Sarcomas. Most of them present their own radiological and histopathological feautures, that are essential to know in order to achieve early diagnosis. In some of them, molecular diagnosis is mandatory, not only in the diagnosis, but also to plan the treatment. On the other hand, and despite the low incidence, a great scientific research effort has been made to achieve new treatment opportunities for these patients even with approved indications. These include new treatments with targeted therapies and immunotherapy, which today represent possible therapeutic options. It is especially important to be attentive to new and potential avenues of research, and to promote the conduct of specific clinical trials for rare sarcomas.

Extraskeletal Myxoid Chondrosarcoma: State of the Art and Current Research on Biology and Clinical Management

Simple Summary

The aim of this review is to provide an overview of the biological basis of pathogenesis and current research in extraskeletal myxoid chondrosarcoma (EMC), together with the state of the art of treatment for localized and advanced disease. EMC is an ultra-rare sarcoma sub-type, more often arising from the soft tissues, marked by specific molecular features consisting in rearrangement of the NR4A3 gene, identified in recent years and very useful to distinguish EMC from other mimics. Available pharmacological treatments in particular are discussed, with a focus on the most recent results and future perspectives.

Abstract

Extraskeletal myxoid chondrosarcoma (EMC) is an ultra-rare mesenchymal neoplasm with uncertain differentiation, which arises mostly in the deep soft tissue of proximal extremities and limb girdles. EMC is marked by a translocation involving the NR4A3 gene, which can be fused in-frame with different partners, most often EWSR1 or TAF1. Although EMC biology is still poorly defined, recent studies have started shedding light on the specific contribution of NR4A3 chimeric proteins to EMC pathogenesis and clinical outcome. Standard treatment for localized disease is surgery, plus or minus radiation therapy with an expected prolonged survival even though the risk of relapse is about 50%. In advanced cases, besides the standard chemotherapy currently used for soft tissue sarcoma, antiangiogenic agents have recently shown promising activity. The aim of this review is to provide the state of the art of treatment for localized and advanced disease, with a focus on pharmacological treatments available for EMC. The biological basis of current research and future perspectives will be also discussed.

Extraskeletal Myxoid Chondrosarcoma with Molecularly Confirmed Diagnosis: A Multicenter Retrospective Study Within the Italian Sarcoma Group

BACKGROUND

Extraskeletal myxoid chondrosarcoma (EMC) is a rare sarcoma of uncertain origin, marked by specific chromosomal translocations involving the NR4A3 gene, and usually characterized by an indolent course. Surgery (with or without radiotherapy) is the treatment of choice in localized disease. The treatment for advanced disease remains uncertain. In order to better evaluate prognostic factors and outcome, a retrospective pooled analysis of patients with EMC treated at three Italian Sarcoma Group (ISG) referral centers was carried out.

METHODS

All patients with localized EMC surgically treated from 1989 to 2016 were identified. Diagnosis was centrally reviewed according to WHO 2013. Only patients with NR4A3 rearrangement were included.

RESULTS

Sixty-seven patients were identified: 13 (20%) female, 54 (80%) male. Median age was 56 years (range 18-84). Numbers and type of translocation were: 50 (80%) NR4A3-EWS, 10 (16%) NR4A3-TAF15, 1 (2%) NR4A3-TCF12, and 1 (2%) NR4A3-TFG. Median follow-up was 55 months (range 2-312). Five- and ten-year overall survival rates were 94% (86-100 95%CI) and 84% (69-98 95%CI). Thirty-five (52%) patients relapsed: 9 had local recurrence (LR) and 26 had distant metastasis (5 with concomitant LR). The 5- and 10-year disease-free survival rates (DFS) were 51% (38-65 95%CI) and 20% (7-33 95%CI). Size of the primary tumor was significantly related to distant metastasis-free survival (DMFS) (p = 0.004). Patients carrying the NR4A3-EWS translocation had a trend in favor of better DFS (p = 0.08) and DMFS (p = 0.09) compared with the patients with NR4A3-TAF15.

CONCLUSIONS

Prolonged survival can be expected in patients with EMC, in spite of a high rate of recurrence. Size is significantly associated with distant relapse. The type of NR4A3 translocation could influence outcome.

Extraskeletal Myxoid Chondrosarcoma: Clinical and Molecular Characteristics and Outcomes of Patients Treated at Two Institutions

Background: Extraskeletal myxoid chondrosarcoma (EMC) is a rare subtype of STS, which usually arises in extremities. It carries reciprocal translocations involving the NR4A3 gene. It displays an indolent behavior, but studies with long follow-up showed a high proportion of local and distant recurrences. For patients with progressing metastatic disease anthracycline-based chemotherapy is the standard front-line regimen, though has limited activity. There is some evidence on possible activity of antiangiogenetics.

Methods: This is a retrospective study conducted at Istituto Oncologico Veneto and at Institut Gustave Roussy. All patients with a confirmed diagnosis of EMC from January 1980 to December 2018 were extracted from a prospectively maintained database.

Results: 59 patients were identified, 37 male (62.7%) and 22 female (37.3%) with a M/F ratio of 1.7/1. We performed molecular analysis in 23 cases, all carried a EWSR1-NR4A3. Out of 49 patients treated with curative intent, 28.6% developed local recurrence and 40.8% patients developed metastases. In patients who had been radically resected (R0) local recurrence occurred in 7.6% of cases and metastases occurred in 15.4% of cases; in patients treated with R1 surgery, rates of relapse were higher. Twenty patients received chemotherapy for metastatic disease; best response was partial response with clinical benefit in 50% of patients. Fourteen patients received a second line of chemotherapy, with 46.1% disease control rate. A drug holiday was proposed to 8 patients with a mean duration of 22.8 months. Median overall survival was 180 months for the study population and 76 months for metastatic patients. No significant prognostic role was found for all studied variables, yet a trend of better survival for complete surgery, location in extremities of primary tumor and solitary lung metastases was observed. Chemotherapy for metastatic disease was negatively associated with survival.

Conclusion: In this large retrospective cohort of patients with ECM, location of primary tumor and solitary lung metastases seem to be associated with better survival. Chemotherapy did not impact survival in unselected patients. Further research is necessary in order to identify more active regimens and to provide clinical and molecular factors to select patients that could delay systemic treatment for metastatic disease.

NR4A3 fusion proteins trigger an axon guidance switch that marks the difference between EWSR1 and TAF15 translocated extraskeletal myxoid chondrosarcomas

Extraskeletal myxoid chondrosarcoma (EMC) is a rare sarcoma histotype with uncertain differentiation. EMC is hallmarked by the rearrangement of the NR4A3 gene, which in most cases fuses with EWSR1 or TAF15. TAF15‐translocated EMC seem to feature a more aggressive course compared to EWSR1‐positive EMCs, but whether the type of NR4A3 chimera impinges upon EMC biology is still largely undefined. To gain insights on this issue, a series of EMC samples (7 EWSR1‐NR4A3 and 5 TAF15‐NR4A3) were transcriptionally profiled. Our study unveiled that the two EMC variants display a distinct transcriptional profile and that the axon guidance pathway is a major discriminant. In particular, class 4–6 semaphorins and axonal guidance cues endowed with pro‐tumorigenic activity were more expressed in TAF15‐NR4A3 tumors; vice versa, class 3 semaphorins, considered to convey growth inhibitory signals, were more abundant in EWSR1‐NR4A3 EMC. Intriguingly, the dichotomy in axon guidance signaling observed in the two tumor variants was recapitulated in in vitro cell models engineered to ectopically express EWSR1‐NR4A3 or TAF15‐NR4A3. Moreover, TAF15‐NR4A3 cells displayed a more pronounced tumorigenic potential, as assessed by anchorage‐independent growth. Overall, our results indicate that the type of NR4A3 chimera dictates an axon guidance switch and impacts on tumor cell biology. These findings may provide a framework for interpretation of the different clinical–pathological features of the two EMC variants and lay down the bases for the development of novel patient stratification criteria and therapeutic approaches. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Extraskeletal myxoid chondrosarcoma with massive pulmonary metastases

Background

Extraskeletal myxoid chondrosarcoma (EMC) is a rare malignant mesenchymal neoplasm of uncertain differentiation characterized by rearrangements of the NR4A3 gene. EMC often affects adults around the age of 50 and arise in the deep tissues of the proximal extremities and limb girdles. EMC is characterized by indolent growth rate but strong tendency to local recurrence and metastatic spread. No systemic treatment is specifically approved by the FDA for this disease and surgery has been traditionally the only potentially curative strategy.

Case presentation

A 41-year-old Caucasian woman originally presented with a 14.8 cm left thigh mass. She was managed with wide local resection but after 2 years she developed recurrent disease in the pelvis and in the lungs; the lung involvement was characterized by innumerable nodules without any significant respiratory symptoms. After failing three clinical trials, she experienced prolonged disease control while on treatment with the tyrosine kinase inhibitor (TKI) pazopanib and radiation therapy delivered to the pelvic lesion. Dose reduction of pazopanib due to severe diarrhea was followed by rapid disease progression in the pelvis requiring vascular stenting; increase in tumor growth after discontinuation of a TKI has been described in other malignancies and is a possibility in this specific patient.

Conclusion

While surgical management of EMC with or without radiation therapy is still the preferable approach when feasible, small series support the use of tyrosine kinase inhibitors and possible new immunotherapies in selected patients. Basket trials focusing on diseases with unique genomic features such as EMC will hopefully provide a better understanding of new options for care.

Extraskeletal myxoid chondrosarcoma with massive pulmonary metastases

Background

Extraskeletal myxoid chondrosarcoma (EMC) is a rare malignant mesenchymal neoplasm of uncertain differentiation characterized by rearrangements of the NR4A3 gene. EMC often affects adults around the age of 50 and arise in the deep tissues of the proximal extremities and limb girdles. EMC is characterized by indolent growth rate but strong tendency to local recurrence and metastatic spread. No systemic treatment is specifically approved by the FDA for this disease and surgery has been traditionally the only potentially curative strategy.

Case presentation

A 41-year-old Caucasian woman originally presented with a 14.8 cm left thigh mass. She was managed with wide local resection but after 2 years she developed recurrent disease in the pelvis and in the lungs; the lung involvement was characterized by innumerable nodules without any significant respiratory symptoms. After failing three clinical trials, she experienced prolonged disease control while on treatment with the tyrosine kinase inhibitor (TKI) pazopanib and radiation therapy delivered to the pelvic lesion. Dose reduction of pazopanib due to severe diarrhea was followed by rapid disease progression in the pelvis requiring vascular stenting; increase in tumor growth after discontinuation of a TKI has been described in other malignancies and is a possibility in this specific patient.

Conclusion

While surgical management of EMC with or without radiation therapy is still the preferable approach when feasible, small series support the use of tyrosine kinase inhibitors and possible new immunotherapies in selected patients. Basket trials focusing on diseases with unique genomic features such as EMC will hopefully provide a better understanding of new options for care.

Systemic manifestations of extraskeletal myxoid chondrosarcoma associated with a novel t(2;22)(q34;q12) EWS translocation in a child and a review of the literature

Extraskeletal myxoid chondrosarcoma (EMC), a soft-tissue sarcoma with unique clinicopathologic features and characteristic chromosomal translocations, is extremely rare in the pediatric population. We, herein, present the case of a 7-year-old boy with profound microcytic hypochromic anemia, poor weight gain and a mid-thoracic paraspinal mass that was identified as EMC. Systemic manifestations of localized, nonmetastatic EMC have never been described in the pediatric population, yet our patient's anemia and poor weight gain resolved after successful surgical resection of the tumor, suggesting that localized EMC can present with systemic manifestations. The tumor also contained a novel t(2;22)(q34;q12) translocation involving the EWSR1 gene, which is consistent with additional reports suggesting that a growing list of translocations can drive formation of, and potential new management strategies for, EMC.

Identification of an Actionable Mutation of KIT in a Case of Extraskeletal Myxoid Chondrosarcoma

Extraskeletal myxoid chondrosarcoma (EMC) is an extremely rare soft tissue sarcoma, marked by a translocation involving the NR4A3 gene. EMC is usually indolent and moderately sensitive to anthracycline-based chemotherapy. Recently, we reported on the therapeutic activity of sunitinib in a series of EMC cases, however the molecular target of sunitinib in EMC is unknown. Moreover, there is still the need to identify alternative therapeutic strategies. To better characterize this disease, we performed whole transcriptome sequencing in five EMC cases. Peculiarly, in one sample, an in-frame deletion (c.1735_1737delGAT p.D579del) was identified in exon 11 of KIT. The deletion was somatic and heterozygous and was validated both at DNA and mRNA level. This sample showed a marked high expression of KIT at the mRNA level and a mild phosphorylation of the receptor. Sanger sequencing of KIT in additional 15 Formalin Fixed Paraffin Embedded (FFPE) EMC did not show any other mutated cases. In conclusion, exon 11 KIT mutation was detected only in one out of 20 EMC cases analyzed, indicating that KIT alteration is not a recurrent event in these tumors and cannot explain the EMC sensitivity to sunitinib, although it is an actionable mutation in the individual case in which it has been identified.

Extraskeletal Myxoid Chondrosarcoma of Nasopharynx: An Oncologic Entity Rarely Reported

Extraskeletal myxoid chondrosarcoma (ESMC) is an extremely rare variant of chondrosarcoma accounting for less than 10% cases. It affects mainly the soft tissues of the proximal end of long bones. Its incidence in the head and neck region is less than 5%. This case presented in the nasopharynx, an exceedingly unusual site for ESMC in a 60-year-old female with left-sided nasal obstruction and occasional epistaxis of one-year duration. Biopsy from the nasopharyngeal mass was suggestive of low-grade chondrosarcoma. She underwent endoscopic resection of the tumor. Postoperative histopathology confirmed the diagnosis as myxoid chondrosarcoma of nasopharynx after performing a battery of immunohistochemical markers to rule out other possible differential diagnoses. We treated her with conformal adjuvant radiotherapy to a dose of 66 Gray in 33 fractions given residual disease to which she responded well with significant symptomatic and radiological improvement. The patient has been on regular follow-up for over two years without any evidence of recurrence or distant metastasis. This case is presented to highlight the extreme rarity, the clinicopathological findings of this disease, and to emphasize the role of radiotherapy as the primary adjuvant treatment affecting the final prognosis. A thorough review of the literature reveals that our case may be the second case of myxoid chondrosarcoma of nasopharynx ever reported in the world literature to date.

Temozolomide post pazopanib treatment failure in patients with advanced sarcoma: A case series

Background

Sarcomas are rare, heterogeneous tumors for which prognosis remains dismal in patients with advanced disease. Pazopanib, a vascular endothelial growth factor receptor inhibitor, has shown modest efficacy in patients with soft tissue sarcoma who fail cytotoxic chemotherapy. The cytotoxic agent temozolomide has also demonstrated activity in patients with advanced sarcoma.

Objective

We performed a retrospective case series to evaluate the feasibility of adding temozolomide to pazopanib in advanced sarcoma patients following single-agent pazopanib failure.

Patients and methods

Patients with recurrent, metastatic sarcomas who had progressed on single-agent pazopanib and continued on pazopanib with the addition of temozolomide were included in this retrospective analysis to examine the tolerability and responses associated with the treatment combination.

Results

Nine patients with a range of sarcoma subtypes were identified (55% female; median age, 48 years; median number of therapies prior to pazopanib, 3). All patients received combination therapy. One patient was recently started on therapy and was excluded from the analysis (n = 8 evaluable patients). Median PFS for single-agent pazopanib was 7.5 months (range 2–19). For the eight evaluable patients (63% female), best response at 4 months with pazopanib plus temozolomide was partial response (n = 1), stable disease (n = 3) and progressive disease (n = 4), with a median PFS of 3.5 months (range 0–15). Median PFS with combination treatment in patients with stable disease or response was 8 months (range 5–15). All four patients who achieved clinical benefit remain on therapy and are tolerating the combination therapy with expected but manageable side effects.

Conclusions

In heavily pretreated patients with advanced sarcoma, the addition of temozolomide to pazopanib was found to be tolerable. Future prospective trials are required to deduce whether temozolomide extends the clinical benefit of pazopanib.

Next generation sequencing of extraskeletal myxoid chondrosarcoma

Extraskeletal myxoid chondrosarcoma (EMC) is an indolent translocation-associated soft tissue sarcoma with a high propensity for metastases. Using a clinical sequencing approach, we genomically profiled patients with metastatic EMC to elucidate the molecular biology and identify potentially actionable mutations. We also evaluated potential predictive factors of benefit to sunitinib, a multi-targeted tyrosine kinase inhibitor with reported activity in a subset of EMC patients. Between January 31, 2012 and April 15, 2016, six patients with EMC participated in the clinical sequencing research study. High quality DNA and RNA was isolated and matched normal samples underwent comprehensive next generation sequencing (whole or OncoSeq capture exome of tumor and normal, tumor PolyA+ and capture transcriptome). The expression levels of sunitinib targeted-kinases were measured by transcriptome sequencing for KDR, PDGFRA/B, KIT, RET, FLT1, and FLT4. The previously reported EWSR1-NR4A3 translocation was identified in all patient tumors; however, other recurring genomic abnormalities were not detected. RET expression was significantly greater in patients with EMC relative to other types of sarcomas except for liposarcoma (p<0.0002). The folate receptor was overexpressed in two patients. Our study demonstrated that similar to other translocation-associated sarcomas, the mutational profile of metastatic EMC is limited beyond the pathognomonic translocation. The clinical significance of RET expression in EMC should be explored. Additional pre-clinical investigations of EMC may help elucidate molecular mechanisms contributing to EMC tumorigenesis that could be translated to the clinical setting.

HSPA8 as a novel fusion partner of NR4A3 in extraskeletal myxoid chondrosarcoma

Extraskeletal myxoid chondrosarcoma (EMC) is a very rare sarcoma most often arising in the soft tissue. Rare EMC of the bone have been reported. EMC exhibits distinctive clinico-pathological and genetic features; however, despite the name, it lacks any feature of cartilaginous differentiation. EMC is characterized by the rearrangement of the NR4A3, which, in most cases (about 62-75%), is fused with EWSR1 and less frequently with other partners, including TAF15 (27%), TCF12 (4%), TFG, and FUS. We herein report the identification by whole-transcriptome sequencing of HSPA8 as a novel fusion partner of NR4A3 in a case of EMC. FISH analysis confirmed the presence of a genomic HSPA8-NR4A3 translocation in the vast majority of tumor cells. Our findings expand the spectrum of NR4A3 fusion partners involved in EMC pathobiology.

Pulmonary extraskeletal myxoid chondrosarcoma: A case report and literature review

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Extraskeletal myxoid chondrosarcoma (EMC) is a rare tumor characterized by the multinodular growth of primitive chondroid cells in an abundant myxoid matrix.

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EMC is categorized as a tumor of uncertain differentiation by the 2002 WHO classification.

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EMC has shown to have the recurrent balanced chromosomal translocation t(9;22) (q22;q12.2), which leads to the oncogenic fusion gene EWSR1-NR4A3.

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EMC usually presents in male patients beyond their fifth decade as a slow growing, palpable mass in the extremities.

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Pulmonary extraskeletal myxoid chondrosarcomas are extremely rare with only isolated case reports found in the literature.

Background

Extraskeletal myxoid chondrosarcoma (EMC) accounts for the 3% of all soft tissue sarcomas and it's categorized as a tumour of uncertain differentiation. This entity has shown to have the recurrent balanced chromosomal translocation t(9;22) (q22;q12.2), which leads to the oncogenic fusion gene EWSR1-NR4A3. This sarcoma usually presents as a slow growing, palpable mass in the extremities. EMC arising from the lung is extremely infrequent. We report one case of pulmonary extraskeletal mixoid chondrosarcoma and a review of the world literature.

Case report

A 69-year-old male patient presented with intermittent hemoptysis for the last 6 months. A PET/CT scan showed a hypermetabolic solid mass with lobulated borders of approximately 29 × 26 mm in the inferior right lobe. We performed a right thoracotomy with inferior lobectomy and lymphadenectomy of levels VII, VIII, X, and XI levels. The neoplasm was constituted by cords of small cells with small round nucleus and scarce cytoplasm immerse in an abundant myxoid matrix. The immunophenotype was positive for MUM-1, CDK4, MDM2, and showed focal expression for S-100 protein and CD56. The final pathology report revealed a pulmonary extraskeletal mixoid chondrosarcoma. No further surgical interventions or adjuvant therapies were needed.

Conclusion

EMC is an intermediate-grade neoplasm, characterized by a long clinical course with high potential for local recurrence and distant metastasis. Treatment for EMC is surgical and non-surgical treatment is reserved for recurrence or metastatic disease. Pulmonary extraskeletal myxoid chondrosarcoma is a rare neoplasm with only isolated case reports found in the literature.

Clinicopathologic and radiologic features of extraskeletal myxoid chondrosarcoma: a retrospective study of 40 Chinese cases with literature review

The aim of this study is to describe the clinicopathologic and radiologic features of 40 cases of extraskeletal myxoid chondrosarcoma (EMC) from China. There were 25 males and 15 females (sex ratio, 1.7:1). Apart from an adolescent, all patients were adults with a median age of 49years. Twenty-four tumors (60%) occurred in the lower limb and limb girdles, especially the thigh, followed by the upper limb and limb girdles (20%) and trunk (10%). Other less commonly involved locations included the head and neck, sacrococcygeal region, and perineum. Tumors ranged in size from 1.5 to 19cm (mean, 7cm). By radiology, they appeared as hypoattenuated or isoattenuated masses on computed tomography with hyperintense signal on T2-weighted magnetic resonance imaging. Intralesional hypointense septa were present in most cases. Of the 40 tumors, 30 belonged to the classic subtype, whereas 9 cases were cellular, and 1 case had a rhabdoid phenotype. Tumor cells showed variable expression of synaptophysin (36%), S-100 protein (29%), epithelial membrane antigen (11%), and neuron-specific enolase (7%). Ki-67 index was remarkably higher in the cellular variant (mean, 30%). EWSR1-related rearrangement was detected in 12 of 14 cases tested by fluorescence in situ hybridization using break-apart probes. The overall 5- and 7-year survival was 71% and 60%, respectively. Awareness of the imaging features may help pathologists in the diagnosis of EMC. Fluorescence in situ hybridization also serves as a useful diagnostic tool for EMC, especially in the distinction from its mimics.

Unresectable Extraskeletal Myxoid Chondrosarcoma of the Neck: Early Tumor Response to Chemoradiotherapy

Extraskeletal myxoid chondrosarcoma (EMC) rarely occurs in the head and neck and is generally managed with primary surgery. To our knowledge, no cases of unresectable EMC of the neck have been reported. We present a case of an unresectable EMC treated with chemotherapy and radiation, and highlight the exceptional early response to therapy. 

Histology-Driven Therapy

Soft tissue tumors (STTs) are rare mesenchymal neoplasms accounting for less than 1% of adult cancers. More than 50 different subtypes of STTs have been identified, with this number expected to grow as our understanding of the complex genetic landscape of these diseases improves. As the classification of soft tissue neoplasms continues to diversify, so does the approach to therapy. Accurate histopathologic diagnosis, utilizing the appropriate ancillary immunohistochemical and molecular diagnostic platforms, underpins the oncologic management of soft tissue sarcomas. As increasing numbers of reproducible genetic abnormalities in soft tissue neoplasms are defined, molecular genetic and molecular cytogenetic investigations have become a standard part of the ancillary diagnostic repertoire. However, other soft tissue neoplasms lack reproducible genetic abnormalities, and for these, traditional histology and immunohistochemistry remain the cornerstones for diagnosis. Here, we give an overview of histology-driven therapy in STTs, highlighting the critical role of accurate surgical pathology in guiding the systemic treatment of patients with these neoplasms, and the importance of close collaboration between the surgical pathologist and the oncologist. We also summarize what is considered standard practice in nonhistology- and histology-driven therapy.

Activity of sunitinib in extraskeletal myxoid chondrosarcoma

BACKGROUND

Extraskeletal myxoid chondrosarcoma (EMC) is a rare soft tissue sarcoma, marked by NR4A3 rearrangement. Herein we report on the activity of sunitinib in a series of 10 patients, strengthening what initially observed in two cases.

PATIENTS AND METHODS

From July 2011, 10 patients with progressive metastatic translocated EMC have been consecutively treated with sunitinib 37.5mg/day, on a named-use basis. In an attempt to interpret the activity of sunitinib in EMC, genotype/phenotype correlations were carried out by fluorescence in situ hybridization (FISH) analyses. Moreover, transcriptome, immunohistochemical and biochemical analyses of a limited set of samples were performed focusing on some putative targets of sunitinib.

RESULTS

Eight of 10 patients are still on therapy. Six patients had a Response Evaluation Criteria in Solid Tumours (RECIST) partial response (PR), two were stable, two progressed. Positron emission tomography (PET) was consistent in 6/6 evaluable cases. One patient underwent surgery after sunitinib, with evidence of a pathologic response. At a median follow-up of 8.5 months (range 2-28), no secondary resistance was detected. Median progression free survival (PFS) has not been reached. Interestingly, all responsive cases turned out to express the typical EWSR1-NR4A3 fusion, while refractory cases carried the alternative TAF15-NR4A3 fusion. Among putative sunitinib targets, only RET was expressed and activated in analysed samples.

CONCLUSIONS

This report confirms the therapeutic activity of sunitinib in EMC. Genotype/phenotype analyses support a correlation between response and EWSR1-NR4A3 fusion. Involvement of RET deserves further investigation.