{
  "abstract": "Introduction: Low-grade fibromyxoid sarcoma (LGFMS) and sclerosing epithelioid fibrosarcoma (SEF) represent a molecularly related spectrum of ultra-rare soft-tissue sarcomas characterised by recurrent FUS or EWSR1 rearrangements and frequent MUC4 expression. Despite sharing recurrent molecular alterations, their clinical behaviour differs markedly, positioning them at opposite ends of a biologically related spectrum with distinct clinical trajectories. This study aimed to characterise the clinicopathological features, molecular profiles, treatment approaches, and outcomes across this spectrum.\n\nMethods: We retrospectively reviewed consecutive patients with LGFMS or SEF at a national EURACAN-designated sarcoma reference centre between 2013 and 2024. Clinicopathological characteristics, molecular findings, treatments, and outcomes were collected and analysed descriptively.\n\nResults: Twenty patients were included: 11 (55%) LGFMS, six (30%) SEF and three (15%) hybrid tumours. MUC4 was positive in 13 cases (65%). Molecular analysis was informative in 19 patients (95%), with FUS or EWSR1 rearrangements in 16 (84%). FUS predominated (63%); EWSR1 rearrangements were confined to SEF (21%). Nineteen patients (95%) underwent curative-intent surgery. Local recurrence occurred in two (10%). Distant metastases developed in three (15%), all with SEF or hybrid histology. Metastatic progression was early (median 6 months), associated with high-risk histological features and EWSR1 rearrangement. SEF accounted for the only disease-related death; median overall survival was not reached, with 95% of patients alive at last follow-up.\n\nDiscussion: These findings highlight the divergent clinical behaviour across the LGFMS–SEF spectrum and support closer surveillance of high-risk tumours.",
  "abstract_shown": true,
  "affiliations": [
    "Medical Oncology Department, Hospital Garcia de Orta",
    "Medical Oncology Department, Instituto Português de Oncologia do Porto Francisco Gentil",
    "Genetics Department, Instituto Português de Oncologia do Porto Francisco Gentil",
    "Pathology Department, Instituto Português de Oncologia do Porto Francisco Gentil",
    "Radiation Oncology Department, Instituto Português de Oncologia do Porto Francisco Gentil",
    "Surgery Department, Instituto Português de Oncologia do Porto Francisco Gentil"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Beatriz Castanheira"
    },
    {
      "affs": [
        1
      ],
      "name": "Inês Soldin"
    },
    {
      "affs": [
        2
      ],
      "name": "Joana Vieira"
    },
    {
      "affs": [
        3
      ],
      "name": "Mariana Afonso"
    },
    {
      "affs": [
        4
      ],
      "name": "Sofia Conde"
    },
    {
      "affs": [
        5
      ],
      "name": "Augusto Moreira"
    },
    {
      "affs": [
        1
      ],
      "name": "Miguel Henriques Abreu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2gnj44dsgg3nq.bib",
  "cited_by": 0,
  "doi": "10.3389/fonc.2026.1943496",
  "fulltext_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13716661/?tool=EBI",
  "id": "2gnj44dsgg3nq",
  "issns": [
    "2234-943X"
  ],
  "landing_url": "https://www.frontiersin.org/articles/10.3389/fonc.2026.1943496/full",
  "language": "eng",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Original Research"
    ],
    [
      "openalex",
      "2740|Sarcoma Diagnosis and Treatment"
    ]
  ],
  "openalex": "W7222065557",
  "pdf_url": "https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2026.1943496/pdf",
  "pmcid": "PMC13716661",
  "pmid": "42959078",
  "published": "2026-10-15",
  "publisher": "Frontiers Media SA",
  "ris": "https://research.draconitic.com/paper/2gnj44dsgg3nq.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:13Z",
      "native_id": "10.3389/fonc.2026.1943496",
      "source": "crossref",
      "url": "https://www.frontiersin.org/articles/10.3389/fonc.2026.1943496/full"
    },
    {
      "first_seen": "2026-10-31T00:20:37Z",
      "native_id": "PMC:PMC13716661",
      "source": "europepmc",
      "url": "https://europepmc.org/article/PMC/PMC13716661"
    },
    {
      "first_seen": "2026-11-01T00:20:52Z",
      "native_id": "MED:42959078",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42959078"
    },
    {
      "first_seen": "2026-11-01T12:23:54Z",
      "native_id": "PMC13716661",
      "source": "pmc",
      "url": "https://doi.org/10.3389/fonc.2026.1943496"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "issn:2234-943X",
      "subfield": "oncology"
    }
  ],
  "title": "Low-grade fibromyxoid and sclerosing epithelioid fibrosarcoma: distinct behaviour in the same spectrum of ultra-rare sarcomas",
  "title_text": "Low-grade fibromyxoid and sclerosing epithelioid fibrosarcoma: distinct behaviour in the same spectrum of ultra-rare sarcomas",
  "type": "peer-reviewed",
  "updated_at": "2026-11-02T12:21:08Z",
  "url": "https://research.draconitic.com/paper/2gnj44dsgg3nq",
  "venue": "Frontiers in Oncology",
  "versions": []
}