# Alveolar soft part sarcoma

Source: https://onco.cc/cancers/alveolar-soft-part-sarcoma/  
OnCo record `alveolar-soft-part-sarcoma` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Alveolar soft part sarcoma is a rare, slow-growing cancer of young adults driven by a single fusion gene, ASPSCR1-TFE3, that switches on blood vessel growth. Chemotherapy does not work, but drugs that block the tumour's blood supply shrink it, and in 2023 the immunotherapy atezolizumab became the first drug approved for it.

## Summary

Alveolar soft part sarcoma is defined by the unbalanced translocation der(17)t(X;17) that fuses ASPSCR1 to the transcription factor TFE3, driving a programme of angiogenesis and metabolic genes; the same TFE3 fusion partner occurs in translocation renal cell carcinoma. The tumour is richly vascular, grows slowly in deep muscle of the limbs of young adults or in the orbit and tongue of children, and metastasises early to the lungs, bone and, unusually for a sarcoma, the brain. Because it is indolent, patients with metastases often survive many years, and the disease is followed with regular brain imaging.

Localised tumours are treated with wide resection, with radiotherapy for close margins, and isolated metastases with surgery or stereotactic radiotherapy. Conventional chemotherapy is ineffective. VEGFR-directed kinase inhibitors are active: sunitinib produced responses in Italian series, cediranib improved progression-free survival against placebo in the randomised CASPS trial, pazopanib is used in Europe, and anlotinib, approved in China for soft tissue sarcoma, showed benefit in the alveolar soft part sarcoma cohort of the APROMISS phase 3 trial.

Despite a low mutational burden, the tumour responds to PD-L1 blockade: the NCI-sponsored phase 2 study of atezolizumab produced durable objective responses in a substantial minority of patients, leading to the first FDA approval for any drug in this disease in December 2023 for unresectable or metastatic alveolar soft part sarcoma in patients aged two and over. Combinations of checkpoint inhibitors with anti-angiogenic drugs, including benmelstobart plus anlotinib, are the main line of current trials.

## Fields

- Kind: Cancer
- Last checked: 2026-09-17
- Also known as: ASPS; ASPSCR1-TFE3 sarcoma
- Tags: subtype-page
- Group: sarcoma
- Burden: Under one percent of soft tissue sarcomas, arising in adolescents and young adults, usually in the thigh or buttock and in children in the head and neck; it grows slowly but has often already spread to the lungs, bone or brain at diagnosis, and patients live for years with metastatic disease.
- Subtypes: Alveolar soft part sarcoma of the deep soft tissue of the limbs (adolescents and young adults); Head and neck (orbit, tongue) alveolar soft part sarcoma in children; Metastatic disease to lung, bone and brain (indolent course)
- Biomarkers: ASPSCR1-TFE3 fusion (FISH or RNA sequencing; TFE3 immunohistochemistry); PAS-positive, diastase-resistant crystals; Brain imaging surveillance for metastases

## Sections of this record

The page is a hub with ten sections in reading order; large sections have their own page. The same plan as JSON: https://onco.cc/api/v1/cancers/alveolar-soft-part-sarcoma/sections.json

- Overview (on the hub): The TL;DR, the family this cancer belongs to, the organ, who gets it and what the state of the art is. https://onco.cc/cancers/alveolar-soft-part-sarcoma/#overview [3 state-of-the-art points]
- Types and stages (on the hub): Anatomy, the subtypes and how they differ, how it is staged, and where advanced disease spreads. https://onco.cc/cancers/alveolar-soft-part-sarcoma/#what-it-is [3 subtypes]
- Symptoms and diagnosis (on the hub): How this cancer shows itself, how the diagnosis is confirmed, and the biomarkers clinicians test for. https://onco.cc/cancers/alveolar-soft-part-sarcoma/#finding-it [3 biomarkers]
- Treatment (on the hub): The standard of care by setting, the medicines, surgery and radiotherapy named in it, and the regimens behind them. https://onco.cc/cancers/alveolar-soft-part-sarcoma/#treating-it [3 settings, 3 decisions with options]
- Trials and papers (on the hub): Trials recruiting now, the landmark trials, the trials held by this cancer's subtypes, the key papers and what they mean, the latest literature, and the milestones year by year. https://onco.cc/cancers/alveolar-soft-part-sarcoma/#evidence [3 trials, 2 key papers, 5 milestones]
- Biology and targets (on the hub): The molecular landscape: the targets and how often each appears, the pathways, the mechanics stages and the preclinical models. https://onco.cc/cancers/alveolar-soft-part-sarcoma/#science [4 targets]
- Countries and centres (own page): Cases by country, the UK and NHS pathway and other country lenses, the expert centres with trials on record, and the centres named on this cancer's subtypes. https://onco.cc/cancers/alveolar-soft-part-sarcoma/where-you-are/
- Decisions and support (on the hub): The decisions you may face, the aids that walk through them, the warnings on record, the first sixty days and the questions to ask. https://onco.cc/cancers/alveolar-soft-part-sarcoma/#living-with-it [14 questions, 6 red cards]
- Pipeline and open problems (own page): Everything in development, the medicines held by this cancer's subtypes, the open problems and what is being done about them, the roadmaps, and what changed on this record. https://onco.cc/cancers/alveolar-soft-part-sarcoma/coming/ [5 medicines, 3 trials, 3 open problems]
- Data (own page): Every connected record, the notes, the JSON, Markdown and RDF twins, and where the record came from and when it was checked. https://onco.cc/cancers/alveolar-soft-part-sarcoma/data/ [29 connected records]

## Standard of care

- Localised: Wide resection with radiotherapy for close or positive margins; surveillance of lungs and brain. ([Limb-salvage surgery and endoprosthetic reconstruction](https://onco.cc/technologies/limb-salvage-surgery/), [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/), [MRI](https://onco.cc/technologies/mri/))
- Advanced, first line: Atezolizumab (FDA approved 2023) or a VEGFR kinase inhibitor (sunitinib, pazopanib; anlotinib in China); conventional chemotherapy is not used. ([Atezolizumab](https://onco.cc/drugs/atezolizumab/), [Immune checkpoint inhibitors](https://onco.cc/technologies/checkpoint-inhibitor/), [Sunitinib](https://onco.cc/drugs/sunitinib/), [Pazopanib](https://onco.cc/drugs/pazopanib/), [Anlotinib](https://onco.cc/drugs/anlotinib/), [Phase III Trial of Anlotinib, Catequentinib in Advanced Alveolar Soft Part Sarcoma, Leiomyosarcoma, Synovial Sarcoma (APROMISS)](https://onco.cc/trials/nct03016819/))
- Oligometastatic: Metastasectomy or stereotactic radiotherapy to lung and brain lesions in slowly progressing disease. ([SBRT / SABR (stereotactic radiotherapy)](https://onco.cc/technologies/sbrt/), [Limb-salvage surgery and endoprosthetic reconstruction](https://onco.cc/technologies/limb-salvage-surgery/))

## State of the art

- Atezolizumab is the first approved therapy, with durable responses despite a low mutational burden.
- Anti-angiogenic kinase inhibitors remain active alternatives and partners for immunotherapy.
- The slow course means long survival with metastases and a need for decades of surveillance.

## Open problems

- Why a low-mutation fusion sarcoma responds to immunotherapy is not understood.
- Brain metastases are common and hard to treat.
- No cure for metastatic disease despite long survival.

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Alveolar_soft_part_sarcoma
- Wikipedia: https://en.wikipedia.org/wiki/Alveolar_soft_part_sarcoma

## Connected records

- cancers: [Epithelioid sarcoma](https://onco.cc/cancers/epithelioid-sarcoma/), [Perivascular epithelioid cell tumour (PEComa)](https://onco.cc/cancers/pecoma/), [Rhabdomyosarcoma](https://onco.cc/cancers/rhabdomyosarcoma/), [Sarcomas (soft tissue, bone, GIST)](https://onco.cc/cancers/sarcoma/), [Soft tissue sarcoma of the extremity (localised and advanced)](https://onco.cc/cancers/extremity-soft-tissue-sarcoma/), [Synovial sarcoma](https://onco.cc/cancers/synovial-sarcoma/)
- drugs: [Anlotinib](https://onco.cc/drugs/anlotinib/), [Atezolizumab](https://onco.cc/drugs/atezolizumab/), [Cediranib](https://onco.cc/drugs/cediranib/), [Pazopanib](https://onco.cc/drugs/pazopanib/), [Sunitinib](https://onco.cc/drugs/sunitinib/)
- key papers: [Atezolizumab for advanced alveolar soft part sarcoma](https://onco.cc/key-papers/paper-atezolizumab-alveolar-soft-part-sarcoma-chen-nejm-2023/), [The der(17)t(X;17) of alveolar soft part sarcoma fuses TFE3 to ASPL](https://onco.cc/key-papers/paper-ladanyi-aspl-tfe3-oncogene-2001/)
- trials: [Clinical Trials of Benmelstobart Injection Combined With Anlotinib Hydrochloride Capsules in the Treatment of Advanced or Unresectable Alveolar Soft Part Sarcoma](https://onco.cc/trials/nct07548177/), [Depsipeptide (Romidepsin) in Treating Patients With Metastatic or Unresectable Soft Tissue Sarcoma](https://onco.cc/trials/nct00112463/), [Phase III Trial of Anlotinib, Catequentinib in Advanced Alveolar Soft Part Sarcoma, Leiomyosarcoma, Synovial Sarcoma (APROMISS)](https://onco.cc/trials/nct03016819/)
- technologies: [Immune checkpoint inhibitors](https://onco.cc/technologies/checkpoint-inhibitor/), [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/), [Limb-salvage surgery and endoprosthetic reconstruction](https://onco.cc/technologies/limb-salvage-surgery/), [MRI](https://onco.cc/technologies/mri/), [SBRT / SABR (stereotactic radiotherapy)](https://onco.cc/technologies/sbrt/)
- people: [Alice P. Chen](https://onco.cc/people/alice-chen/)

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JSON: https://onco.cc/api/v1/entities/alveolar-soft-part-sarcoma.json