An unusual case of primary splenic soft part alveolar sarcoma: case report and review of the literature with emphasis on the spectrum of TFE3-associated neoplasms.

BACKGROUND: Alveolar soft part sarcoma is a rare tumour of soft tissues, mostly localized in muscles or deep soft tissues of the extremities. In rare occasions, this tumour develops in deep tissues of the abdomen or pelvis. CASE PRESENTATION: In this case report, we described the case of a 46 year old man who developed a primary splenic alveolar soft part sarcoma. The tumour displayed typical morphological alveolar aspect, as well as immunohistochemical profile notably TFE3 nuclear staining. Detection of ASPSCR1 Exon 7::TFE3 Exon 6 fusion transcript in molecular biology and TFE3 rearrangement in FISH confirmed the diagnosis. CONCLUSION: We described the first case of primary splenic alveolar soft part sarcoma, which questions once again the cell of origin of this rare tumour.

Establishment and characterization of NCC-ASPS2-C1: a novel patient-derived cell line of alveolar soft part sarcoma.

Alveolar soft part sarcoma (ASPS) is a rare mesenchymal tumor characterized by rearrangement of the ASPSCR1 and TFE3 genes and a histologically distinctive pseudoalveolar pattern. ASPS progresses slowly, but is prone to late metastasis. As ASPS is refractory to conventional chemotherapy, the only curative treatment is complete surgical resection. The prognosis of advanced and metastatic cases is poor, highlighting the need for preclinical research to develop appropriate treatment options. However, ASPS is extremely rare, accounting for < 1% of all soft tissue sarcomas, and only one patient-derived ASPS cell line is available from public cell banks worldwide for research. This study reports the establishment of a novel ASPS cell line derived from the primary tumor tissue of an ASPS patient, named NCC-ASPS2-C1. This cell line retains the ASPSCR1-TFE3 fusion gene, which is characteristic of ASPS. The characterization of this cell line revealed stable growth, spheroid formation, and invasive properties. By screening a drug library using NCC-ASPS2-C1, we identified several drugs that inhibited the proliferation of ASPS cells. In conclusion, the establishment of NCC-ASPS2-C1 provides a valuable resource for advancing ASPS research and developing novel treatments for this challenging disease.

Evaluation of TRIM63 RNA in situ hybridization (RNA-ISH) as a potential biomarker for alveolar soft-part sarcoma (ASPS).

Alveolar soft-part sarcoma (ASPS) is a rare soft tissue tumor with a broad morphologic differential diagnosis. While histology and immunohistochemistry can be suggestive, diagnosis often requires exclusion of other entities followed by confirmatory molecular analysis for its characteristic ASPSCR1-TFE3 fusion. Current stain-based biomarkers (such as immunohistochemistry for cathepsin K and TFE3) show relatively high sensitivity but may lack specificity, often showing staining in multiple other entities under diagnostic consideration. Given the discovery of RNA in situ hybridization (RNA-ISH) for TRIM63 as a sensitive and specific marker of MiTF-family aberration renal cell carcinomas, we sought to evaluate its utility in the workup of ASPS. TRIM63 RNA-ISH demonstrated high levels (H-score greater than 200) of expression in 19/20 (95%) cases of ASPS (average H-score 330) and was weak or negative in cases of paraganglioma, clear cell sarcoma, rhabdomyosarcoma, malignant epithelioid hemangioendothelioma, as well as hepatocellular and adrenal cortical carcinomas. Staining was also identified in tumors with known subsets characterized by TFE3 alterations such as perivascular epithelioid cell neoplasm (PEComa, average H-score 228), while tumors known to exhibit overexpression of TFE3 protein without cytogenetic alterations, such as melanoma and granular cell tumor, generally showed less TRIM63 ISH staining (average H-scores 147 and 96, respectively). Quantitative assessment of TRIM63 staining by RNA-ISH is potentially a helpful biomarker for tumors with molecular TFE3 alterations such as ASPS.

Alveolar soft part sarcoma: a clinicopathological and immunohistochemical analysis of 26 cases emphasizing risk factors and prognosis.

OBJECTIVE: This study aimed to investigate the clinicopathological features and prognostic indicators of alveolar soft part sarcoma (ASPS). METHODS: The characteristics of 26 ASPS patients diagnosed at our hospital between January 2011 and January 2019 were retrospectively analysed. RESULTS: The data for 12 male and 14 female patients, with a median age of 27.5 years, were assessed. The clinical symptoms mainly included painless enlarged masses in deep soft tissues. ASPS had a characteristic pathological morphology. Twenty-four patients were positive for TFE3, and TFE3 gene rearrangement was detected in 12 patients. Among the 26 patients who completed follow-up, 14 had metastasis, 1 had local recurrence, and 7 died. Kaplan-Meier survival analysis revealed that prognosis was significantly correlated with sex, tumour size and metastasis (P < 0.05). Multivariate Cox regression analysis revealed that sex and metastasis were independent prognostic risk factors for patients with ASPS (P < 0.05). CONCLUSION: ASPS is a rare soft tissue sarcoma of unknown origin that occurs in young people, has a slow but metastatic course, and is associated with a poor 5-year survival rate among patients with metastasis. ASPS has character TFE3 protein and gene expression, and the diagnosis is relatively specific. The diagnosis requires comprehensive analysis of clinical history, histological morphology, and immunohistochemistry.

PEComa with ASPSCR1::TFE3 fusion: expanding the molecular genetic spectrum of TFE3-rearranged PEComa with an emphasis on overlap with alveolar soft part sarcoma.

AIMS: Mesenchymal neoplasms involving TFE3 gene fusions are diverse, mainly include alveolar soft part sarcoma (ASPS) that is characterised by ASPSCR1::TFE3 fusion, and a small subset of perivascular epithelioid cell tumours (PEComas) referred to as TFE3-rearranged PEComa, that most frequently harbours SFPQ::TFE3 fusion. Historically, ASPS and TFE3-rearranged PEComa are considered two distinctive entities despite their known morphological overlap. However, recent studies have suggested a potential histogenetic relationship between them, and several neoplasms that showed morphological features more closely fit PEComa rather than ASPS but harboured ASPSCR1::TFE3 fusion have been documented. In this study, we report three cases of PEComa with ASPSCR1::TFE3 fusion. METHODS AND RESULTS: Clinicopathological features were assessed and partner agnostic targeted next-generation sequencing on clinically validated platforms were performed. The patients are two females and one male with age at presentation ranging from 21 to 51 years. All three tumours were located in the viscera (rectum, kidney and cervix). On a relatively limited follow-up period (range = 9-15 months), all patients are alive without evidence of recurrent or metastatic disease. The neoplasms were composed of tight nested architecture of epithelioid clear cells separated by a delicate vascular network, two of which were associated with sheets of plump spindle cells, and none showed significant discohesive tumour morphology. Immunohistochemically, in addition to TFE3 protein, all three neoplasms demonstrated co-expression of melan-A and smooth muscle actin. RNA-sequencing identified ASPSCR1::TFE3 fusion in all three cases that were confirmed by subsequent fluorescence in-situ hybridisation analyses. CONCLUSIONS: Our study expands the molecular genetic spectrum of TFE3-rearranged PEComa and further indicates its close relationship to ASPS.

Alveolar soft part sarcoma in a child - a case report.

BACKGROUND: Alveolar soft part sarcoma (ASPS) is a very rare mesenchymal malignancy of uncertain origin. It mostly affects young people, with about a quarter of cases being diagnosed in children. CASE: An 11-year-old girl had a painless subcutaneous "lump" in the left elbow area. Imaging exams revealed a solid soft-tissue intramuscular mass of suspicious appearance. A surgical excision of lesion was performed. The biopsy consisted of a lobular tumor measuring 35 × 20 × 12 mm. Histology revealed an epithelioid-cell population arranged in organoid pseudoalveolar pattern. It immunohistochemically expressed TFE3 and harbored the ASPSCR1:: TFE3 gene fusion. A diagnosis of ASPS was established. Subsequently, a wide re-excision of the scar was performed without microscopic residual tumor. The patient is currently without evidence of local recurrence or metastasis. CONCLUSION: ASPS is considered an aggressive and prognostically unfavorable chemoresistant neoplasm. Children have a better prognosis compared to adults. Early detection of tumor in a localized stage with complete surgical removal remains a mainstay therapeutic option. Due to its tendency to late metastases, a long-term thorough follow-up of the patient is necessary.

Advances in treatment of alveolar soft part sarcoma: an updated review.

Alveolar soft part sarcoma is a rare neoplasm of uncertain histogenesis that belongs to a newly defined category of ultra-rare sarcomas. The neoplasm is characterized by a specific chromosomal translocation, der (17) t(X; 17)(p11.2;q25), that results in ASPSCR1-TFE3 gene fusion. The natural history of alveolar soft part sarcoma describes indolent behaviour with slow progression in deep soft tissues of the extremities, trunk and head/neck in adolescents and young adults. A high rate of detection of distant metastasis at presentation has been reported, and the most common metastatic sites in decreasing order of frequency are the lung, bone and brain. Complete surgical resection remains the standard treatment strategy, whereas radiotherapy is indicated for patients with inadequate surgical margins or unresectable tumours. Although alveolar soft part sarcoma is refractory to conventional doxorubicin-based chemotherapy, monotherapy or combination therapy using tyrosine kinase inhibitors and immune checkpoint inhibitors have provided antitumor activity and emerged as new treatment strategies. This article provides an overview of the current understanding of this ultra-rare sarcoma and recent advancements in treatments according to the clinical stage of alveolar soft part sarcoma.

ASPSCR1::TFE3 orchestrates the angiogenic program of alveolar soft part sarcoma.

Alveolar soft part sarcoma (ASPS) is a soft part malignancy affecting adolescents and young adults. ASPS is characterized by a highly integrated vascular network, and its high metastatic potential indicates the importance of ASPS's prominent angiogenic activity. Here, we find that the expression of ASPSCR1::TFE3, the fusion transcription factor causatively associated with ASPS, is dispensable for in vitro tumor maintenance; however, it is required for in vivo tumor development via angiogenesis. ASPSCR1::TFE3 is frequently associated with super-enhancers (SEs) upon its DNA binding, and the loss of its expression induces SE-distribution dynamic modification related to genes belonging to the angiogenesis pathway. Using epigenomic CRISPR/dCas9 screening, we identify Pdgfb, Rab27a, Sytl2, and Vwf as critical targets associated with reduced enhancer activities due to the ASPSCR1::TFE3 loss. Upregulation of Rab27a and Sytl2 promotes angiogenic factor-trafficking to facilitate ASPS vascular network construction. ASPSCR1::TFE3 thus orchestrates higher ordered angiogenesis via modulating the SE activity.

A case report and literature review on nephrogenic alveolar soft part sarcoma: clinicopathological manifestations and genetic features.

BACKGROUND: Alveolar soft part sarcoma (ASPS) is a rare kind of malignant soft tissue tumor with undefined differentiation, of which the incidence rate accounts for only 0.5-1.0% among all kinds of soft tissue tumors. An even rarer ASPS occurs in kidney. CASE PRESENTATION: Here we reported a case of a 7-year-old girl diagnosed with nephrogenic ASPS, regarding the analyses of the incidence, clinical manifestation, pathology and genetic diagnosis, in order to deepen the recognition of the disease. CONCLUSIONS: ASPS is very rare, and tends to occur to young patients. It is very significant to precisely diagnose ASPS at an early stage, which will be the key point for the following treatment choices and prognosis.

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.

Examining Stripes on a Herd of Zebras: Impact of Genomic Matching for Ultrarare Sarcomas in Phase 1 Clinical Trials (SAMBA 102).

PURPOSE: Recently, the Connective Tissue Oncology Society published consensus guidelines for recognizing ultrarare sarcomas (URS), defined as sarcomas with an incidence ≤1 per 1,000,000. We assessed the outcomes of 56 patients with soft tissue, and 21 with bone sarcomas, enrolled in Phase 1 trials. EXPERIMENTAL DESIGN: In this Sarcoma-Matched Biomarker Analysis (SAMBA-102 study), we reviewed records from patients on Phase 1 trials at the University of Texas MD Anderson Cancer Center between January 2013 and June 2021. RESULTS: Among 587 sarcomas, 106 (18.1%) were classified as URS. Fifty (47%) were male, and the median age was 44.3 years (range, 19-82). The most common subtypes were alveolar soft part sarcoma (ASPS), chordoma, dedifferentiated chondrosarcoma, and sclerosing epithelioid fibrosarcoma. Compared with common sarcomas, median OS was similar 16.1 months [95% confidence interval (CI), 13.6-17.5] versus 16.1 (95% CI, 8.2-24.0) in URS (P = 0.359). Objective response to treatment was higher in URS 13.2% (n = 14/106) compared with common sarcomas 6.9% (n = 33/481; P = 0.029). Median OS for those treated on matched trials was 27.3 months (95% CI, 1.9-52.7) compared with 13.4 months (95% CI, 6.3-20.6) for those not treated on matched trials (P = 0.291). Eight of 33 (24%) molecularly matched treatments resulted in an objective response, whereas 6 of 73 unmatched treatments (8.2%) resulted in an objective response (P = 0.024). Clinical benefit rate was 36.4% (12/33) in matched trials versus 26.0% (19/73) in unmatched trials (P = 0.279). CONCLUSIONS: The results demonstrate the benefit of genomic selection in Phase 1 trials to help identify molecular subsets likely to benefit from targeted therapy.

Primary Alveolar Soft-Part Sarcoma of the Lung: A Case Report.

Alveolar soft-part sarcoma is a rare type of soft tissue malignant tumor. Although the tumor can occur in many parts of the body, primary alveolar soft-part sarcoma of the lung is extremely rare. According to previous literature, only 3 cases of primary alveolar soft-part sarcoma of the lung were reported, and no comprehensive analysis was conducted on these cases. Here, we describe another case of alveolar soft-part sarcoma in the lung, where the negative results of immunohistochemical staining cause extreme difficulty in distinguishing this lesion from other tumors. A 30-year-old Chinese male presented with chest pain and dyspnea. Computed tomography revealed a pulmonary mass, and biopsy results showed vacuolar tumor cells with abundant eosinophilic cytoplasm. A number of immunohistochemical markers were negative, but the tumor cells were positive for TFE3 and ASPSCR1::TFE3 fusion gene. No other tumor masses were found in the patient after whole-body scanning. The final diagnosis was primary alveolar soft-part sarcoma of the lung. Pathologists should consider the possibility of alveolar soft-part sarcoma in lung tumors with typical "organ like" or "acinar like" cell nests, where the tumor cells are large, vacuolated, and the nucleolus is obvious. After excluding metastasis from other sites, TFE3 immunohistochemical staining and ASPSCR1::TFE3 fusion gene detection are recommended for the diagnosis of primary alveolar soft-part sarcoma.

Correlation of Immunological and Molecular Profiles with Response to Crizotinib in Alveolar Soft Part Sarcoma: An Exploratory Study Related to the EORTC 90101 "CREATE" Trial.

Alveolar soft part sarcoma (ASPS) is a rare subtype of soft tissue sarcoma characterized by an unbalanced translocation, resulting in ASPSCR1-TFE3 fusion that transcriptionally upregulates MET expression. The European Organization for Research and Treatment of Cancer (EORTC) 90101 "CREATE" phase II trial evaluated the MET inhibitor crizotinib in ASPS patients, achieving only limited antitumor activity. We performed a comprehensive molecular analysis of ASPS tissue samples collected in this trial to identify potential biomarkers correlating with treatment outcome. A tissue microarray containing 47 ASPS cases was used for the characterization of the tumor microenvironment using multiplex immunofluorescence. DNA isolated from 34 available tumor samples was analyzed to detect recurrent gene copy number alterations (CNAs) and mutations by low-coverage whole-genome sequencing and whole-exome sequencing. Pathway enrichment analysis was used to identify diseased-associated pathways in ASPS sarcomagenesis. Kaplan-Meier estimates, Cox regression, and the Fisher's exact test were used to correlate histopathological and molecular findings with clinical data related to crizotinib treatment, aiming to identify potential factors associated with patient outcome. Tumor microenvironment characterization showed the presence of PD-L1 and CTLA-4 in 10 and 2 tumors, respectively, and the absence of PD-1 in all specimens. Apart from CD68, other immunological markers were rarely expressed, suggesting a low level of tumor-infiltrating lymphocytes in ASPS. By CNA analysis, we detected a number of broad and focal alterations. The most common alteration was the loss of chromosomal region 1p36.32 in 44% of cases. The loss of chromosomal regions 1p36.32, 1p33, 1p22.2, and 8p was associated with shorter progression-free survival. Using whole-exome sequencing, 13 cancer-associated genes were found to be mutated in at least three cases. Pathway enrichment analysis identified genetic alterations in NOTCH signaling, chromatin organization, and SUMOylation pathways. NOTCH4 intracellular domain dysregulation was associated with poor outcome, while inactivation of the beta-catenin/TCF complex correlated with improved outcome in patients receiving crizotinib. ASPS is characterized by molecular heterogeneity. We identify genetic aberrations potentially predictive of treatment outcome during crizotinib therapy and provide additional insights into the biology of ASPS, paving the way to improve treatment approaches for this extremely rare malignancy.

Advances in the management of alveolar soft part sarcoma.

Alveolar Soft Part Sarcoma is one of the less commonly diagnosed soft tissue sarcoma subtypes, an infrequent subtype within the already rare category of human malignancy of sarcoma. In this article we will summarize the histopathological features, natural history and distinct molecular and biological features that have become increasingly appreciated with newer technologies and precision oncology. We will discuss the contemporary management of this disease as well as emerging treatment options.

Lingual alveolar soft part sarcoma with absent TFE3 rearrangement.

BACKGROUND: Lingual ASPS is extremely rare and aggressive tumor. rearrangement is typically detected in ASPS patients using FISH analysis. AIM: To present the clinical, histopathological, and radiological features of lingual Alveolar Soft Part Sarcoma. METHOD: A 30-year-old male presented with a painless, slowly growing mass of the tongue. Initial impression was of benign vascular lesion. Later, the patient became symptomatic as the mass progressed in size, which necessitated further investigations. RESULT: A lip-split, mandibulotomy was performed for the excision of the tumor and revealed an alveolar soft part sarcoma with PAS-positive, diastase resistant intracytoplasmic granules. However, molecular analysis using FISH was negative for TFE3 rearrangement. Patient underwent partial glossectomy with postoperative radiotherapy. CONCLUSION: Clinical and pathological correlation of ASPS is very useful to reach a proper diagnosis.

Gene of the month: TFE 3.

Transcription factor enhancer 3 (TFE3), on the short arm of chromosome Xp11.23 and its protein, belongs to the microphthalmia transcription family (MiTF) of transcription factors. It shares close homology with another member of the family, MiTF which is involved in melanocyte development. When a cell is stressed and/or starved, TFE3 protein translocates into the nucleus. TFE3 gene fusions with multiple different partner genes occur in several tumours with resultant nuclear expression of TFE3 protein. The main tumours associated with TFE3 gene fusions are: renal cell carcinoma, alveolar soft part sarcoma, a subset of epithelioid haemangioendotheliomas (EHE), some perivascular epithelioid cell tumours and rare examples of ossifying fibromyxoid tumour and malignant chondroid syringoma. TFE3 immunohistochemistry is of use in routine diagnostic practice with the aforementioned tumours harbouring TFE3 fusions leading to nuclear staining. In addition, there are tumours lacking TFE3 fusions but also display TFE3 nuclear immunolabeling, and these include: granular cell tumour, solid pseudopapillary neoplasm of the pancreas and ovarian sclerosing stromal tumour.

Establishment and characterization of NCC-ASPS1-C1: a novel patient-derived cell line of alveolar soft-part sarcoma.

Alveolar soft-part sarcoma is a mesenchymal malignancy characterized by the rearrangement of ASPSCR1 and TFE3 and a histologically distinctive pseudoalveolar pattern. Although alveolar soft-part sarcoma takes an indolent course, its long-term prognosis is poor because of late distant metastases. Currently, curative treatments have not been found for alveolar soft-part sarcoma, and hence, a novel therapeutic strategy has long been required. Patient-derived cell lines comprise an important tool for basic and preclinical research. However, few cell lines from alveolar soft-part sarcoma have been reported in the literature because it is an extremely rare malignancy, accounting for less than 1% of all soft-tissue sarcomas. This study aimed to establish a novel alveolar soft-part sarcoma cell line. Using surgically-resected tumor tissue of alveolar soft-part sarcoma, we successfully established a cell line and named it NCC-ASPS1-C1. The NCC-ASPS1-C1 cells harbored an ASPSCR1-TFE3 fusion gene and exhibited slow growth, and spheroid formation. On the other hand, NCC-ASPS1-C1 did not show the capability of invasion. We screened the antiproliferative effects of 195 anticancer agents, including Food and Drug Administration-approved anticancer drugs. We found that the MET inhibitor tivantinib and multi-kinase inhibitor orantinib inhibited the proliferation of NCC-ASPS1-C1 cells. The clinical utility and molecular mechanisms of antitumor effects of these drugs are worth investigating in the further studies, and NCC-ASPS1-C1 cells will be a useful tool for the in vitro study of alveolar soft-part sarcoma.

Establishment and characterization of a novel alveolar rhabdomyosarcoma cell line, NCC-aRMS1-C1.

Alveolar rhabdomyosarcoma (aRMS) is a histological subtype of RMS, which is the most common pediatric and adolescent soft-tissue sarcoma, accounting for 3-4% of all pediatric malignancies. Patient-derived cells are essential tools for understanding the molecular mechanisms of poor prognosis and developing novel anti-cancer drugs. However, only a limited number of well-characterized cell lines for rhabdomyosarcoma from public cell banks is available. Therefore, we aimed to establish a novel cell line of aRMS from the tumor tissue of a patient with aRMS. The cell line was established from surgically resected tumor tissue from a 4-year-old male patient diagnosed with stage III, T2bN1M0 aRMS and was named as NCC-aRMS1-C1. The cells were maintained for more than 3 months under tissue culture conditions and passaged more than 20 times. We confirmed the presence of identical fusion gene such as PAX7-FOXO1 in both the original tumor and NCC-aRMS1-C1. The cells exhibited spheroid formation and invasion. We found that docetaxel, vincristine, ifosfamide, dacarbazine, and romidepsin showed remarkable growth-suppressive effects on the NCC-aRMS1-C1 cells. In conclusion, the NCC-aRMS1-C1 cell line exhibited characteristics that may correspond to the lymph node metastasis in aRMS and mirror its less aggressive features. Thus, it may be useful for innovative seeds for novel therapeutic strategies.

Novel therapeutic options for alveolar soft part sarcoma: antiangiogenic therapy, immunotherapy and beyond.

PURPOSE OF REVIEW: Alveolar soft part sarcoma (ASPS) represent 0.5% of sarcomas, defining a rarest among rare malignancies. It affects young adults, displaying slow-growing mass of the thigh, head and neck, and trunk. Although quite indolent, a majority of cases displays an advanced disease with lung bone or central nervous system metastasis. Complete surgery is the cornerstone of localized ASPS, and advanced diseases poorly respond to chemotherapy. Here discuss recent progress in molecular characterization of ASPS and future prospects of therapeutic approaches. RECENT FINDINGS: ASPS is characterized by a specific oncogenic translocation ASPSCR1-TFE3 that induce hepatocyte growth factor receptor (MET) overexpression, angiogenesis, and immunosuppression in the tumor microenvironment. These specific biological features have encouraged the successful exploration of MET inhibitors, antiangiogenic drugs, and immunotherapy. We reviewed the main tracks of ASPS biology and recent insights from targeted therapies is ASPS mainly driven tyrosine kinase inhibitors (especially antiangiogenics), immune-checkpoint inhibitors, and their combinations. SUMMARY: Overall, antiangiogenics and anti Programmed cell death 1/Programmed cell death ligand 1 therapies showed a significant activity in ASPS that warrants additional investigation through randomized trials to validate those results and through ancillary biological studies to better understand resistance mechanisms and biomarkers of response.