Alveolar soft part sarcomas: molecular pathogenesis and implications for novel targeted therapies

Biological and therapeutic insights from animal modeling of fusion-driven pediatric soft tissue sarcomas

Survival for children with cancer has primarily improved over the past decades due to refinements in surgery, radiation and chemotherapy. Although these general therapies are sometimes curative, the cancer often recurs, resulting in poor outcomes for patients. Fusion-driven pediatric soft tissue sarcomas are genetically defined by chromosomal translocations that create a chimeric oncogene. This distinctive, almost 'monogenic', genetic feature supports the generation of animal models to study the respective diseases in vivo. This Review focuses on a subset of fusion-driven pediatric soft tissue sarcomas that have transgenic animal tumor models, which includes fusion-positive and infantile rhabdomyosarcoma, synovial sarcoma, undifferentiated small round cell sarcoma, alveolar soft part sarcoma and clear cell sarcoma. Studies using the animal models of these sarcomas have highlighted that pediatric cancers require a specific cellular state or developmental stage to drive tumorigenesis, as the fusion oncogenes cause different outcomes depending on their lineage and timing of expression. Therefore, understanding these context-specific activities could identify targetable activities and mechanisms critical for tumorigenesis. Broadly, these cancers show dependencies on chromatin regulators to support oncogenic gene expression and co-opting of developmental pathways. Comparative analyses across lineages and tumor models will further provide biological and therapeutic insights to improve outcomes for these children.

Comparative genomics incorporating translocation renal cell carcinoma mouse model reveals molecular mechanisms of tumorigenesis

Translocation renal cell carcinoma (tRCC) most commonly involves an ASPSCR1-TFE3 fusion, but molecular mechanisms remain elusive and animal models are lacking. Here, we show that human ASPSCR1-TFE3 driven by Pax8-Cre (a credentialed clear cell RCC driver) disrupted nephrogenesis and glomerular development, causing neonatal death, while the clear cell RCC failed driver, Sglt2-Cre, induced aggressive tRCC (as well as alveolar soft part sarcoma) with complete penetrance and short latency. However, in both contexts, ASPSCR1-TFE3 led to characteristic morphological cellular changes, loss of epithelial markers, and an epithelial-mesenchymal transition. Electron microscopy of tRCC tumors showed lysosome expansion, and functional studies revealed simultaneous activation of autophagy and mTORC1 pathways. Comparative genomic analyses encompassing an institutional human tRCC cohort (including a hitherto unreported SFPQ-TFEB fusion) and a variety of tumorgraft models (ASPSCR1-TFE3, PRCC-TFE3, SFPQ-TFE3, RBM10-TFE3, and MALAT1-TFEB) disclosed significant convergence in canonical pathways (cell cycle, lysosome, and mTORC1) and less established pathways such as Myc, E2F, and inflammation (IL-6/JAK/STAT3, interferon-γ, TLR signaling, systemic lupus, etc.). Therapeutic trials (adjusted for human drug exposures) showed antitumor activity of cabozantinib. Overall, this study provides insight into MiT/TFE-driven tumorigenesis, including the cell of origin, and characterizes diverse mouse models available for research.

Everolimus in combination with vandetanib in children, adolescents, and young adults: a phase I study

BACKGROUND

Combined use of inhibitors of mammalian target of rapamycin (mTOR) and vascular endothelial growth factor (VEGF-2) receptors is a potential strategy to overcome resistance to either class of drugs when used alone.

PATIENTS AND METHODS

We designed a phase 1 trial to test the drug combination of a multikinase VEGF receptor 2 inhibitor, vandetanib, and an mTOR inhibitor, everolimus, in a pediatric and young adult patient cohort with advanced cancers. Exceptional responders were probed for tumor mutational profile to explore possible molecular mechanisms of response.

RESULTS

Among 21 enrolled patients, clinical benefit was observed in 38% (one patient with partial response and eight patients with stable disease) with a median progression-free survival of 3.3 months. The most common treatment-related adverse event was rash (n = 13). Other treatment-related toxicities included diarrhea, fatigue, hypertension, QT prolongation, hypertriglyceridemia/hypercholesterolemia, transaminitis, thrombocytopenia, and weight loss. None of the patients experienced dose-limiting toxicities. Three exceptional responders were analyzed and were found to harbor genetic alterations including kinase insert domain receptor (KDR) Q472H mutation, EWSR1-CREB3L1, CDKN2A/B loss, and ASPL/ASPSCR1-TFE3 fusion.

CONCLUSIONS

The combination of vandetanib and everolimus showed early activity and tolerable toxicity profile in pediatric patients with advanced cancers.

Primary Alveolar Soft-Part Sarcoma (ASPS) of the Prostate: Report of a Deceptive Case

Alveolar soft-part sarcoma (ASPS) is a rare soft tissue tumor that primarily involves the extremities. We report a case of a 30-year-old never-smoker man who presented with hematuria, dysuria, and constipation at an outside hospital. He was diagnosed with and treated for multiple episodes of urinary tract infection. However, he continued to have voiding symptoms for which a cystoscopy was performed and revealed a bladder neck mass. He underwent transurethral resection of a bladder tumor and was diagnosed with muscle-invasive urothelial carcinoma, nested variant, at an outside hospital. Subsequent to this diagnosis he transferred his care to our center. In-house imaging revealed a large vascular mass involving the prostate and pushing against the bladder base. Prostate needle biopsies were performed and revealed an epithelioid neoplasm with a nested growth pattern composed of cells with a moderate amount of eosinophilic cytoplasm, mildly pleomorphic nuclei, and occasional prominent nucleoli. Since the findings were not classic for urothelial carcinoma or for prostate cancer, we included a wider differential of poorly differentiated carcinoma, sarcoma, and paraganglioma. A wide panel of keratin stains was negative, ETS (erythroblast transformation-specific)-related gene highlighted an extensive vascular network and neuroendocrine stains were all negative. A transcription factor E3 fluorescent in-situ hybridization was positive and subsequently, an ASPSCR1 gene rearrangement was demonstrated. The outside hospital transurethral resection of bladder tumor was obtained for review and the tumor was morphologically similar to that seen on the in-house prostate needle biopsies. Based on the above findings a final diagnosis of primary ASPS of the prostate with involvement of the bladder was made. The patient was later diagnosed with bilateral lung metastases. He was treated with pazopanib, radiation therapy, and cystoprostatectomy and is symptom-free on a 15-month follow-up.

Rhabdomyosarcoma Associated with Core Myopathy/Malignant Hyperthermia: Combined Effect of Germline Variants in RYR1 and ASPSCR1 May Play a Role

Rhabdomyosarcomas have been described in association with thyroid disease, dermatomyositis, Duchenne muscular dystrophy, and in muscular dystrophy models but not in patients with ryanodine receptor-1 gene (RYR1) pathogenic variants. We described here an 18-year-old male who reported a cervical nodule. Magnetic resonance images revealed a mass in the ethmoidal sinus corresponding to rhabdomyosarcoma. As his father died from malignant hyperthermia (MH), an in vitro contracture test was conducted and was positive for MH susceptibility. Muscle histopathological analysis in the biopsy showed the presence of cores. Molecular analysis using NGS sequencing identified germline variants in the RYR1 and ASPSCR1 (alveolar soft part sarcoma) genes. This report expands the spectrum of diseases associated with rhabdomyosarcomas and a possible differential diagnosis of soft tissue tumors in patients with RYR1 variants.

Lingual Alveolar Soft Part Sarcoma in a 78-Year-Old Woman: A Case Report and Comprehensive Review of the Literature from 1952 to 2022

BACKGROUND

Alveolar soft part sarcoma (ASPS) is a rare translocation-related soft tissue sarcoma, occurring mainly in the limbs and trunk in young adults and adolescents. ASPS is rarely seen in the head and neck and one fourth of those cases described are tongue primary. Given its nonspecific symptoms, clinical findings, and rarity in this location, lingual ASPS (L-ASPS) has been reported to be commonly misdiagnosed as various benign tumors, leading to adverse outcomes.

METHODS

We report a case of L-ASPS occurring in the oldest (78 years) female patient published to date and comprehensively review the literature from 1952 to 2022.

RESULTS

She presented with a slow-growing (2-year duration) tongue mass, measuring 3.5 cm on palpation. Intraoperative frozen section could not render the definitive diagnosis. The pathological findings of the tumor were characteristic of ASPS with eosinophilic polygonal cells in an organoid/nested pattern, rich sinusoidal capillaries, and TFE3 immunoreactivity, except for the strong diffuse aberrant cytoplasmic CD68 immunoexpression and absence of intracytoplasmic crystalline inclusions on PAS with diastase. After TFE3 gene rearrangement had been identified with fluorescent in-situ hybridization, reflex testing confirmed a rearrangement of TFE3 gene with the known fusion partner ASPSCR1.

CONCLUSIONS

ASPS should be included in the differential diagnoses in cases of any slow-growing lingual masses (especially vascular ones) with non-specific clinical pictures, regardless of the patient's age.

Case report: Primary alveolar soft-part sarcoma of the lung in a child

Alveolar soft-part sarcoma involving the lung is mostly metastatic in nature, while primary alveolar soft-part sarcoma involving the lung occurs more rarely. Herein, we report a rare case of a patient with primary alveolar soft-part sarcoma of the lung, which may represent the earliest onset of this condition reported thus far. In this patient, surgery was performed to excise the lesion to the greatest extent possible, and the combination of surgery with chemoradiotherapy and an antiangiogenic agent may provide an important reference for the development of standard or first-line treatment for such pediatric patients.

Complex Elucidation of Cells-of-Origin in Pediatric Soft Tissue Sarcoma: From Concepts to Real Life, Hide-and-Seek through Epigenetic and Transcriptional Reprogramming

Soft tissue sarcoma (STS) comprise a large group of mesenchymal malignant tumors with heterogeneous cellular morphology, proliferative index, genetic lesions and, more importantly, clinical features. Full elucidation of this wide diversity remains a central question to improve their therapeutic management and the identity of cell(s)-of-origin from which these tumors arise is part of this enigma. Cellular reprogramming allows transitions of a mature cell between phenotypes, or identities, and represents one key driver of tumoral heterogeneity. Here, we discuss how cellular reprogramming mediated by driver genes in STS can profoundly reshape the molecular and morphological features of a transformed cell and lead to erroneous interpretation of its cell-of-origin. This review questions the fact that the epigenetic context in which a genetic alteration arises has to be taken into account as a key determinant of STS tumor initiation and progression. Retracing the cancer-initiating cell and its clonal evolution, notably via epigenetic approach, appears as a key lever for understanding the origin of these tumors and improving their clinical management.

Molecular Targets for Novel Therapeutics in Pediatric Fusion-Positive Non-CNS Solid Tumors

Chromosomal fusions encoding novel molecular drivers have been identified in several solid tumors, and in recent years the identification of such pathogenetic events in tumor specimens has become clinically actionable. Pediatric sarcomas and other rare tumors that occur in children as well as adults are a group of heterogeneous tumors often with driver gene fusions for which some therapeutics have already been developed and approved, and others where there is opportunity for progress and innovation to impact on patient outcomes. We review the chromosomal rearrangements that represent oncogenic events in pediatric solid tumors outside of the central nervous system (CNS), such as Ewing Sarcoma, Rhabdomyosarcoma, Fibrolamellar Hepatocellular Carcinoma, and Renal Cell Carcinoma, among others. Various therapeutics such as CDK4/6, FGFR, ALK, VEGF, EGFR, PDGFR, NTRK, PARP, mTOR, BRAF, IGF1R, HDAC inhibitors are being explored among other novel therapeutic strategies such as ONC201/TIC10.

Alveolar soft part sarcoma in childhood and adolescence: Report of three cases and review of literature

Alveolar soft part sarcoma (ASPS) is a rare soft tissue sarcoma with unique tumor characteristics, which is rare in children. Herein, we present the immunophenotype, treatment, and prognosis of three children with ASPS from The Second Xiangya Hospital of Central South University, and 51 children with ASPS have been reported in the previous literature, along with a focused review of the clinical features, pathological features, differential diagnosis, treatment, and prognosis of ASPS in pediatric patients.

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.

Combined immunotherapy and targeted treatment for primary alveolar soft part sarcoma of the lung: case report and literature review

Primary acinar soft part sarcoma of the lung (ASPS) is a rare malignancy with unique cellular structure and clinical and genetic characteristics. Most patients do not exhibit clear clinical symptoms, with only a few developing respiratory symptoms. The typical histological characteristics are acinoid or organ-like structures. Immunofluorescence in situ hybridization suggests a rearrangement of the transcription factor E3 gene. Patients respond poorly to chemotherapy and are, thus, primarily treated with surgery and targeted therapy. We report herein a unique case of primary alveolar soft part sarcoma of the lung. The patient was a 24-year-old man with metastases to multiple organs, such as the brain, lungs, pancreas, and liver. The craniocerebral lesions attained partial remission after whole-brain radiotherapy and targeted combined immunotherapy, and other distant metastases completely disappeared after targeted combined immunotherapy (anlotinib and camrelizumab), indicating significant treatment efficacy. Anlotinib is an oral multi-target tyrosine kinase inhibitor (TKI) that exerts its anti-tumor effects by acting on various kinases. Camrelizumab is a humanized immunoglobulin G4 monoclonal antibody that can target PD-1 to block the interaction between PD-L1 and programmed death ligand 2, ultimately causing an anti-tumor effect. This is the first report of successful use of anlotinib combined with camrelizumab in the treatment of advanced primary ASPS. The treatment benefit provides preliminary evidence that targeted therapy, combined with immunotherapy, may be a safe and effective approach to treat primary pulmonary ASPS patients, thus warranting further investigation.

Alveolar Soft Part Sarcoma Metastasizing to the Brain: A Rare Entity Revisited with Review of Recent Literature

A 20-year-old male patient presented with a recent history of two episodes of seizures and Glasgow Coma Scale of E3V3M6. He was drowsy at presentation with bradycardia. On further examination, he was found to be having a 10 × 6cm well-circumscribed mass in the right medial thigh whose fine needle aspiration cytology was suggestive of soft tissue sarcoma. Contrast-enhanced magnetic resonance imaging brain showed enhancing lobulated lesions in bilateral hemispheres with significant edema. A decision to decompress the intracranial space occupying lesion was taken. Left-sided larger brain lesions underwent total gross excision followed by excision of the thigh mass. Histopathology of brain lesion was suggestive of metastatic deposits of alveolar soft part sarcoma, whereas the thigh mass was suggestive of alveolar soft part sarcoma grade 2 according to Fédération Nationale des Centres de Lutte Contre Le Cancer grading system. Postoperative course of the patient was unremarkable and his general condition improved remarkably (Functional Assessment of Cancer Therapy–Brain version 4 score improvement >50% at 1 month). He is in follow-up for the last 12 months and currently has completed chemoradiotherapy and is living a self-sufficient life. Though patients with aforementioned rare diagnosis have overall poor prognosis, decompressive craniotomy with metastasectomy may improve the overall quality of life of such young patients, and further chemoradiotherapy may help in prolonging life with acceptable level of comorbidity. This case is being discussed here in terms of the rarity of the final diagnosis, the management strategy used, and the quality of life improvement.

The efficacy and safety of apatinib in metastatic alveolar soft part sarcoma: a case series of six patients in one institution

Background: Evidence suggests that advanced or metastatic alveolar soft part sarcoma (ASPS) with high metastatic potential is chemo-resistant. However, the benefits of tyrosine kinase inhibitors have been demonstrated for the treatment of ASPS.

Purpose: This study aimed to investigate the efficacy and safety of apatinib, aspecific VEGFR-2 inhibitor, in ASPS patients. This retrospective analysis involved six patients with metastatic ASPS not amenable to curative treatment.

Patients and methods: Apatinib was administered at a dose of 500mg per day. Tumor responses were assessed according to the Response Evaluation Criteria in Solid Tumors (RECIST 1.1) guidelines. Survival analysis was performed using the Kaplan–Meier test, and a safety profile was recorded.

Results: The mean age of patients was 26.5 (range, 17–32) years. The median progression-free survival (PFS) was 18.53 months (95% CI, 12.23-NE). However, median overall survival (OS) has not been reached. Twenty-four month PFS and OS rates were 50.0% and 100.0%, respectively. One patient achieved a complete response, and the remaining patients achieved partial responses, with an objective response rate of 100%. Median follow-up was 20.6 (range, 12.43–34.13) months. The most common adverse events included gastrointestinal discomfort (4/6[66.7%]), hair hypopigmentation (4/6[66.7%]) and hand-foot skin reaction (3/6[50.0%]).

Conclusion: Apatinib shows beneficial activity in metastatic ASPS patients, and further studies are warranted with more cases and longer follow-up periods to fully characterize clinical efficacy and safety of apatinib in ASPS.

Alveolar soft-part sarcoma of the prostate: a case report and review of the literature

Alveolar soft-part sarcoma (ASPS) is a rare malignant soft tissue tumor of uncertain cellular origin. We reported the case of a 21-year-old man with ASPS presenting itself as a markedly vascular tumor of the prostate. Immunohistochemistry showed positive nuclear staining for TFE3, positive cytoplasm staining for MyoD1 and neuron-specific enolase, and negative for S100, CK, synaptophysin, chromogranin A, myogenin and PSA. A dual-color, break-apart fluorescence in situ hybridization (FISH) assay identified the presence of a TFE3 gene fusion in the tumor cells. RT-PCR was performed to confirm the ASPSCR1 (ASPL)/TFE3 fusion transcript product in the tumor tissue. The patient suffered bone metastases 8 months after surgery and died of cachexia 14 months later. ASPS of the prostate should be discussed in terms of differential diagnosis from clinicopathological characteristics, immunophenotypes, and molecular genetic features.

More Than 50 Subtypes of Soft Tissue Sarcoma: Paving the Path for Histology-Driven Treatments

Sarcomas are a diverse group of cancers with mesenchymal origin. Although sarcomas comprise less than 1% of cancers, there are more than 50 different subtypes that are quite different from one another in terms of both their biology and clinical behavior. Historically, the need for adequate patient numbers in clinical trials has pushed sarcoma researchers to lump these very different malignancies together and treat the patients using a "one-size-fits-all" approach. However, with improvements in our scientific understanding, we are finally ready for a histology-tailored therapeutic approach to these complex diseases. In this review, we discuss key advances in our understanding of the biology underlying selected sarcoma subtypes and how targeting these subtypes is relevant therapeutically with respect to both molecularly targeted agents as well as immunotherapy.

Human Cytomegalovirus is Present in Alveolar Soft Part Sarcoma

Alveolar soft part sarcoma (ASPS) is an exquisitely rare sarcoma of unknown histogenesis, with a predilection for adolescents and young adults, characterized by slow progressive clinical course and high frequency of metastases. They are traditionally chemoresistant with very limited treatment options in the metastatic setting. Human cytomegalovirus (HCMV) is a DNA β-herpes virus and it is characterized by persistent lifelong and latent infection. There is growing evidence to indicate the presence of HCMV proteins and nucleic acids in glioblastoma, medulloblastoma, rhabdomyosarcoma, and a variety of solid organ malignancies of the breast, prostate, lung, and colon at very high prevalence. Immunotherapy-based clinical trials targeting specific cytomegalovirus proteins are currently in progress in the treatment of glioblastoma. Herein, we evaluated for the presence of HCMV proteins (IE1 and pp65), genes (US28 and UL96), and RNA in a cohort of ASPS. Six confirmed cases of ASPS were retrieved and full thickness sections of formalin-fixed paraffin-embedded material were stained for anti-HMCV-IE1 and anti-HCMV-pp65. Any nuclear and/or cytoplasmic staining was considered positive. DNA was purified from 50 µm of formalin-fixed paraffin-embedded material. One hundred nanogram of DNA was amplified using polymerase chain reaction for primers specific to HCMV-US28 (forward: AGCGTGCCGTGTACGTTAC and reverse: ATAAAGACAAGCACGACC) and HCMV-UL96 (forward: ACAGCTCTTAAAGGACGTGATGCG and reverse: ACCGTGTCCTTCAGCTCGGTTAAA) using Promega Taq polymerase. HCMV in situ hybridization was performed. All 6 cases of ASPS were positive for both HCMV-IE1 and HCMV-pp65. Usable DNA was available in 4 of the 6 cases. HCMV-US28 gene was found in 75% (3/4) of cases and HCMV-UL96 gene was detected in 50% (2/4) of cases. Importantly, all cases tested positive for at least 1 gene. HCMV-encoded RNA was identified in 80% (4/5) of cases. The presence of HCMV DNA, RNA along with HCMV protein indicates that HCMV is present in ASPS and may contribute to its pathogenesis.

Brain metastatic alveolar soft-part sarcoma: Clinicopathological profiles, management and outcomes

Alveolar soft-part sarcoma (ASPS) is a rare sarcoma that presents in the buttocks or thigh of young adults and often metastasizes to the brain. The present study examined the clinical features and morphology of brain metastatic ASPS. The case records of eight patients with brain metastatic ASPS admitted between November 2008 and March 2015 were reviewed. The relevant clinical data (including patient age and sex, neuroimaging studies, histopathological and immunohistochemical features, surgical records and follow-up reports) were collected through a review of patient records. The sex distribution was 3:1 male to female and the age ranged between 15 and 33 years at the time of surgery. In total, five patients with brain metastases had concurrent pulmonary metastases. The lesions were hypointense on T1-weighted images in every patient, hyperintense on T2-weighted images in six patients and contrast enhancement was present in all patients. The most notable immunohistochemical feature was strong immunohistochemical staining for TFE3 in each patient. Gross total resection was performed in all eight patients, with two patients undergoing adjuvant radiotherapy and one undergoing adjuvant chemotherapy. Four recurrent cases were observed during the follow-up. TFE3 staining and knowledge of its microscopic characteristics would facilitate earlier diagnosis: Early diagnosis with a multidisciplinary, multimodal approach to treatment is required to achieve extended disease-free survival in patients with brain metastatic ASPS.

Long-term Results of Therapy with Sunitinib in Metastatic Alveolar Soft Part Sarcoma

Background

Alveolar soft part sarcoma (ASPS) is a rare, highly vascularized soft tissue sarcoma characterized by a high frequency of metastatic disease and resistance to classical chemotherapy. The purpose of our analysis was to assess long-term sunitinib activity in the treatment of metastatic ASPS.

Patients and Methods

Between 2009 and 2015, 15 patients were diagnosed with metastatic ASPS and received therapy with sunitinib at initial continuous daily dosing of 37.5 mg. Median age was 32 years. The primary tumor sites were lower extremities ( 8 ), trunk-retroperitoneum/pelvis ( 2 ), upper extremity ( 3 ) and other ( 2 ). All patients had unresectable disease (primary or relapse in the form of metastases to the lungs ± bones). Five patients received systemic therapy before initiating sunitinib. Median follow-up from start of sunitinib was 38 months (range 5-69 months).

Results

At the time of analysis 4 patients continue therapy and 9 are still alive. Six patients had RECIST partial remission as best response, 8 had stable disease, and 1 had disease progression. The median progression-free survival was 19 months, with 86% of patients being free of progression at 6 months. Median overall survival was 56 months; the 5-year overall survival rate was 49%. Five patients were treated with sunitinib longer than 2 years. All patients experienced some side effects: 8 patients (53%) had CTCAE grade 3/4 toxicity, 7 patients required dose reduction. The most common toxicities were neutropenia, thrombocytopenia, hypothyroidism, arterial hypertension, and hand-foot syndrome.

Conclusions

Our analysis confirms the long-term efficacy of sunitinib in patients with advanced ASPS.

Identification of target genes of cediranib in alveolar soft part sarcoma using a gene microarray

The aim of the present study was to identify the target genes of cediranib and the associated signaling pathways in alveolar soft part sarcoma (ASPS). A microarray dataset (GSE32569) was obtained from the Gene Expression Omnibus database. The R software package was used for data normalization and screening of differentially expressed genes (DEGs). The Database for Annotation, Visualization and Integrated Discovery was used to perform Gene Ontology analysis. Gene Set Enrichment Analysis was performed to obtain the up- and downregulated pathways in ASPS. The Distant Regulatory Elements of co-regulated genes database was used to identify the transcription factors (TFs) that were enriched in the signaling pathways. A protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins database and was visualized using Cytoscape software. A total of 71 DEGs, including 59 upregulated genes and 12 downregulated genes, were identified. Gene sets associated with ASPS were enriched primarily in four signaling pathways: The phenylalanine metabolism pathway, the mitogen-activated protein kinase (MAPK) signaling pathway, the taste transduction pathway and the intestinal immune network for the production of immunoglobulin A. Furthermore, 107 TFs were identified to be enriched in the MAPK signaling pathway. Certain genes, including those coding for Fms-like tyrosine kinase 1, kinase insert domain receptor, E-selectin and platelet-derived growth factor receptor D, that were associated with other genes in the PPI network, were identified. The present study identified certain potential target genes and the associated signaling pathways of cediranib action in ASPS, which may be helpful in understanding the efficacy of cediranib and the development of new targets for cediranib.

Alveolar Soft Part Sarcoma

Alveolar soft part sarcoma is a rare neoplasm usually arising in the soft tissues of the lower limbs in adults and in the head and neck region in children. It presents primarily as a slowly growing mass or as metastatic disease. It is characterized by a specific chromosomal alteration, der(17)t(X:17)(p11:q25), resulting in fusion of the transcription factor E3 (TFE3) with alveolar soft part sarcoma critical region 1 (ASPSCR1) at 17q25. This translocation is diagnostically useful because the tumor nuclei are positive for TFE3 by immunohistochemistry. Real-time polymerase chain reaction to detect the ASPSCR1-TFE3 fusion transcript on paraffin-embedded tissue blocks has been shown to be more sensitive and specific than detection of TFE3 by immunohistochemical stain. Cathepsin K is a relatively recent immunohistochemical stain that can aid in the diagnosis. The recent discovery of the role of the ASPSCR1-TFE3 fusion protein in the MET proto-oncogene signaling pathway promoting angiogenesis and cell proliferation offers a promising targeted molecular therapy.

[Alveolar soft part sarcoma in pediatric patients]

Alveolar soft part sarcoma, ASPS, is a rare malignant tumor, with preferential primary localization in limbs, usually occurring in adolescents and young adults. This sarcoma, well defined histologically and at molecular level, has an indolent course, but a high potential metastatic pulmonary and cerebral evolution, sometimes late. ASPS is characterized by an almost specific translocation t(X, 17)(p11;25) which creates a fusion protein, APSL-TFE3, acting as an aberrant transcription factor. An in-bloc resection of the primary tumor is the treatment of choice in cases of localized disease. Conventional chemotherapy is generally ineffective. The role of radiotherapy is discussed in case of micro- or macroscopical incomplete residue. It seems to reduce local recurrence, but did not influence overall survival. The 5 years survival rate in children, adolescents and young adults is close to 80% in case of localized disease but poorer in presence of metastases. Recently, systemic anti-tumoral treatments have been focused on the use of targeted therapies. Anti-angiogenic drugs and tyrosine kinase inhibitors are the most promising approaches, but require further study. Prognostic risk factors in the literature are age (>10Y), tumor size (>5cm) and presence of metastases. This article reviews the clinical manifestations, diagnosis modalities, radiographic characteristics and therapeutic strategy of this disease in the pediatric population.

Alveolar soft part sarcoma

Alveolar soft part sarcoma (ASPS) is a rare form of soft tissue sarcoma and is most often seen in adolescents and young adults. Despite its unique histology and well-characterised genetic translocation, many questions remain regarding the pathogenesis and treatment of this tumour type. Surgical excision of the primary tumour and pulmonary metastases has resulted in prolonged survival of some patients while the benefit of adjuvant chemotherapy and/or radiotherapy has been disputed. A 35-year-old woman presented with a tumour in the right leg and right side of the mandible along with active metastasis to lungs and multiple skeletal sites.

Imaging features of primary and metastatic alveolar soft part sarcoma: single institute experience in 25 patients

OBJECTIVE

To describe imaging features of primary and metastatic alveolar soft part sarcoma (ASPS).

METHODS

In this institutional review board-approved and Health Insurance Portability and Accountability Act-compliant retrospective study, 25 patients (14 males; mean age, 25 years; range, 18-40 years) with pathologically proven ASPS seen at our institute between 1995 and 2013 were included. Imaging of primary tumours in 5 patients and follow-up imaging in 25 patients were reviewed by 2 radiologists in consensus. Clinical information was obtained from electronic medical records.

RESULTS

The most common sites for the primary tumour were extremities (17/25, 68%) and torso (6/25, 24%). Primary tumours (n = 5) were well circumscribed, compared with skeletal muscle, were isodense on CT, hyperintense on T1 and T2 weighted images with intense post-contrast enhancement, prominent feeders on CT and flow voids on MRI. Metastases developed in 23/25 (92%) patients, 18 at presentation. The most common sites of metastases were the lungs (100%), lymph nodes (74%), bones (57%) and brain (43%). Visceral and nodal metastases were hypervascular. At the time of reporting the results, 15 patients have died, 6 are alive and 4 were lost to follow-up. Median survival was 74 months for those without brain metastases (n = 8) and 60 months for those with brain metastases (n = 7). Median survival was shorter for patients with metastases at presentation.

CONCLUSION

ASPS most commonly involves the lower extremities of young adults, is hypervascular on imaging, often metastasizes at presentation, frequently to lung, nodes, bones and brain, and has an indolent course despite metastases. Brain metastases and high tumour burden (number of metastatic sites) at presentation decreased survival in our study.

ADVANCES IN KNOWLEDGE

ASPS has an unusual pattern of metastases to the brain and nodes in addition to lung and bones. It has an indolent course despite metastases.