Clear Cell Sarcoma - Disorder Mechanisms

🏷

Classifications

Harrison's Chapter

ICD-O Morphology

◆

Subtypes

2

Classic Clear Cell Sarcoma

The typical form arising in deep soft tissues of extremities, associated with tendons and aponeuroses. Characterized by nests of pale cells with melanocytic differentiation.

Show evidence (1 reference)

PMID:40004764 SUPPORT Human Clinical

"Clinically, CCS commonly involves tendons and aponeuroses, with metastatic potential leading to poor prognoses despite optimal local disease management."

Supports the classic CCS presentation in deep soft tissues associated with tendons and aponeuroses.

Clear Cell Sarcoma of the Gastrointestinal Tract

A related but distinct entity arising in the gastrointestinal tract, most commonly stomach or small intestine. Harbors EWSR1-CREB1 fusion and has different clinical behavior.

Show evidence (1 reference)

PMID:41749894 SUPPORT Human Clinical

"CCS is defined by EWSR1-ATF1/CREB1 fusions but exhibits low responsiveness to conventional chemotherapy."

Supports the existence of EWSR1-CREB1 fusion as an alternative defining genetic feature of CCS subtypes.

⚙

Pathophysiology

3

EWSR1-ATF1 Fusion Oncogene

The t(12;22)(q13;q12) translocation fuses the EWSR1 gene on chromosome 22 with ATF1 on chromosome 12 in approximately 90% of cases. The fusion protein functions as an aberrant transcription factor that constitutively activates MITF (microphthalmia-associated transcription factor), driving melanocytic differentiation and survival programs.

positive regulation of transcription by RNA polymerase II link ⚠ ABNORMAL

tendon link

Downstream

MITF Activation EWSR1-ATF1 is associated with MITF expression in CCS

Show evidence (1 reference)

PMID:9793401 PARTIAL

"reciprocal translocation between the long arms of chromosomes 12 and 22"

Supports the characteristic t(12;22) translocation in clear cell sarcoma.

MITF Activation

CCS shows MITF expression consistent with activation downstream of the EWSR1-ATF1 fusion. MITF is the master transcription factor of melanocyte lineage and activates genes involved in melanogenesis, cell survival, and proliferation. This explains the melanocytic phenotype despite soft tissue origin.

regulation of gene expression link ⚠ ABNORMAL

Downstream

Melanocytic Differentiation MITF activates melanocyte differentiation program

Show evidence (1 reference)

PMID:11211309 PARTIAL Human Clinical

"D5 immunoreactivity in clear cell sarcoma provides further evidence for melanocytic differentiation in this unusual tumor."

Shows MITF protein expression in CCS, consistent with activation downstream of EWSR1-ATF1, but does not directly demonstrate transcriptional activation by the fusion.

Melanocytic Differentiation

Downstream of MITF activation, CCS cells express melanocytic markers including S100, HMB45, Melan-A, and tyrosinase. Melanin pigment may be present. However, unlike melanoma, CCS lacks UV-induced mutations and BRAF/NRAS alterations typical of cutaneous melanoma.

cell differentiation link ⚠ ABNORMAL

Show evidence (1 reference)

PMID:11211309 SUPPORT Human Clinical

"S-100 protein expression was seen in all 12 cases that had clear cell sarcoma examined. HMB-45 staining was seen in 11 of 12 (92%) tumors. Focal Melan-A positivity was seen in 3 of 7 (43%) tumors."

Directly supports expression of melanocytic markers (S-100, HMB45, Melan-A) in clear cell sarcoma, evidence of melanocytic differentiation.

✶

Histopathology

1

Malignant Melanoma of Soft Parts VERY_FREQUENT

Clear cell sarcoma is also known as malignant melanoma of soft parts.

Show evidence (1 reference)

PMID:11211309 SUPPORT

"sarcoma (also known as malignant melanoma of soft parts)."

Abstract notes clear cell sarcoma is also known as malignant melanoma of soft parts.

⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

●

Phenotypes

4

Cardiovascular 1

Lymph Node Involvement FREQUENT Lymphadenopathy (HP:0002716)

Show evidence (1 reference)

PMID:40004764 SUPPORT Human Clinical

"wide surgical excision remains the cornerstone for localized disease, with sentinel lymph node biopsy aiding in staging."

The routine use of sentinel lymph node biopsy in CCS staging supports the propensity for lymph node involvement in this disease.

Constitutional 1

Localized Pain FREQUENT Pain (HP:0012531)

Growth 1

Weight Loss OCCASIONAL Weight loss (HP:0001824)

Neoplasm 1

Soft Tissue Mass VERY_FREQUENT Soft tissue neoplasm (HP:0031459)

Show evidence (1 reference)

PMID:40004764 SUPPORT Human Clinical

"Clear Cell Sarcoma (CCS) of soft tissue is a rare and highly malignant neoplasm primarily affecting young adults, often presenting in the deep soft tissues of the extremities."

Supports the typical clinical presentation of CCS as a deep soft tissue mass in the extremities.

🧬

Genetic Associations

1

EWSR1-ATF1 Fusion (Somatic Fusion Oncogene)

Show evidence (2 references)

PMID:40004764 SUPPORT Human Clinical

"CCS arises from connective tissues and is characterized by a distinct genetic hallmark: the EWSR1-ATF1 fusion resulting from t(12;22)(q13;q12) translocation."

Directly supports the EWSR1-ATF1 fusion from t(12;22)(q13;q12) as the defining genetic driver of CCS.

PMID:41749894 SUPPORT Human Clinical

"CCS is defined by EWSR1-ATF1/CREB1 fusions but exhibits low responsiveness to conventional chemotherapy."

Supports both EWSR1-ATF1 and the alternative EWSR1-CREB1 fusion as genetic hallmarks of CCS.

💊

Treatments

4

Wide Surgical Resection

Action: surgical procedure MAXO:0000004

Wide surgical excision with negative margins is the primary treatment. The tendency to arise near tendons and joints may complicate resection. Amputation may be necessary for large or recurrent tumors.

Show evidence (1 reference)

PMID:40004764 SUPPORT Human Clinical

"Therapeutically, wide surgical excision remains the cornerstone for localized disease"

Directly supports wide surgical excision as the cornerstone treatment for localized CCS.

Sentinel Lymph Node Biopsy

Action: surgical procedure MAXO:0000004

Given the propensity for lymph node metastasis, sentinel lymph node biopsy is often performed for staging, similar to melanoma management.

Show evidence (1 reference)

PMID:40004764 SUPPORT Human Clinical

"wide surgical excision remains the cornerstone for localized disease, with sentinel lymph node biopsy aiding in staging."

Directly supports sentinel lymph node biopsy as a staging modality in CCS management.

Radiation Therapy

Action: radiation therapy MAXO:0000014

Adjuvant radiation may be used for close or positive margins or for unresectable disease. CCS is relatively radioresistant.

Show evidence (1 reference)

PMID:40004764 SUPPORT Human Clinical

"Adjuvant radiotherapy is considered in select cases, while chemotherapy has limited efficacy in metastatic settings."

Supports the selective use of adjuvant radiotherapy in CCS management.

Systemic Therapy

Action: chemotherapy MAXO:0000647

Agent: doxorubicin ↗

CCS is generally chemoresistant. Doxorubicin-based regimens may be attempted for metastatic disease but response rates are low. Unlike melanoma, checkpoint inhibitors have limited efficacy.

Show evidence (2 references)

PMID:41749894 SUPPORT Human Clinical

"CCS is defined by EWSR1-ATF1/CREB1 fusions but exhibits low responsiveness to conventional chemotherapy."

Directly supports the chemoresistant nature of CCS that limits the efficacy of systemic chemotherapy.

PMID:40004764 SUPPORT Human Clinical

"chemotherapy has limited efficacy in metastatic settings."

Supports the limited efficacy of chemotherapy in metastatic CCS, framing systemic therapy as palliative.

🔬

Biochemical Markers

2

EWSR1-ATF1 Fusion Detection

Show evidence (1 reference)

PMID:40004764 SUPPORT Human Clinical

"CCS arises from connective tissues and is characterized by a distinct genetic hallmark: the EWSR1-ATF1 fusion resulting from t(12;22)(q13;q12) translocation. This genetic signature is absent in melanoma, making molecular diagnosis essential for accurate differentiation."

Directly supports detection of the EWSR1-ATF1 fusion as a defining diagnostic biochemical feature distinguishing CCS from melanoma.

Melanocytic Markers

Show evidence (1 reference)

PMID:11211309 SUPPORT Human Clinical

"S-100 protein expression was seen in all 12 cases that had clear cell sarcoma examined. HMB-45 staining was seen in 11 of 12 (92%) tumors. Focal Melan-A positivity was seen in 3 of 7 (43%) tumors."

Directly supports the immunohistochemical detection of melanocytic markers (S-100, HMB-45, Melan-A) in CCS.

{ }

Source YAML

click to show

name: Clear Cell Sarcoma
creation_date: '2026-01-26T02:55:13Z'
updated_date: '2026-04-11T21:17:25Z'
description: >-
  Clear cell sarcoma (CCS), also known as melanoma of soft parts, is a rare
  translocation-driven soft tissue sarcoma characterized by the EWSR1-ATF1 or
  EWSR1-CREB1 fusion genes. Despite its name and melanocytic differentiation
  with expression of melanin and melanocytic markers, CCS is genetically and
  clinically distinct from cutaneous melanoma. The EWSR1-ATF1 fusion activates
  MITF, the master regulator of melanocyte development, explaining the melanocytic
  phenotype. CCS typically affects young adults and arises in deep soft tissues
  of the extremities, often associated with tendons and aponeuroses. It has a
  propensity for lymph node metastasis and poor long-term outcomes.
categories:
- Sarcoma
- Soft Tissue Sarcoma
- Rare Cancer
parents:
- soft tissue sarcoma
has_subtypes:
- name: Classic Clear Cell Sarcoma
  description: >-
    The typical form arising in deep soft tissues of extremities, associated
    with tendons and aponeuroses. Characterized by nests of pale cells with
    melanocytic differentiation.
  evidence:
  - reference: PMID:40004764
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Clinically, CCS commonly involves tendons and aponeuroses, with metastatic potential leading to poor prognoses despite optimal local disease management."
    explanation: Supports the classic CCS presentation in deep soft tissues associated with tendons and aponeuroses.
- name: Clear Cell Sarcoma of the Gastrointestinal Tract
  description: >-
    A related but distinct entity arising in the gastrointestinal tract,
    most commonly stomach or small intestine. Harbors EWSR1-CREB1 fusion
    and has different clinical behavior.
  evidence:
  - reference: PMID:41749894
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "CCS is defined by EWSR1-ATF1/CREB1 fusions but exhibits low responsiveness to conventional chemotherapy."
    explanation: Supports the existence of EWSR1-CREB1 fusion as an alternative defining genetic feature of CCS subtypes.
pathophysiology:
- name: EWSR1-ATF1 Fusion Oncogene
  description: >-
    The t(12;22)(q13;q12) translocation fuses the EWSR1 gene on chromosome 22
    with ATF1 on chromosome 12 in approximately 90% of cases. The fusion protein
    functions as an aberrant transcription factor that constitutively activates
    MITF (microphthalmia-associated transcription factor), driving melanocytic
    differentiation and survival programs.
  evidence:
  - reference: PMID:9793401
    reference_title: "[Clear cell sarcoma of soft tissues. Clinico-pathological and ultrastructural analysis of a case in the head-neck region and a literature review]."
    supports: PARTIAL
    snippet: "reciprocal translocation between the long arms of chromosomes 12 and 22"
    explanation: "Supports the characteristic t(12;22) translocation in clear cell sarcoma."
  biological_processes:
  - preferred_term: positive regulation of transcription by RNA polymerase II
    modifier: ABNORMAL
    term:
      id: GO:0045944
      label: positive regulation of transcription by RNA polymerase II
  locations:
  - preferred_term: tendon
    term:
      id: UBERON:0000043
      label: tendon
  downstream:
  - target: MITF Activation
    description: EWSR1-ATF1 is associated with MITF expression in CCS
    evidence:
    - reference: PMID:11211309
      supports: PARTIAL
      evidence_source: HUMAN_CLINICAL
      snippet: "Microphthalmia transcription factor, a melanocytic nuclear protein critical for the embryonic development and postnatal viability of melanocytes, is a master regulator in modulating extracellular signals."
      explanation: Identifies MITF as a central melanocytic regulator, which is consistent with its placement downstream of the EWSR1-ATF1 fusion in CCS but does not directly demonstrate transcriptional activation by the fusion.
- name: MITF Activation
  description: >-
    CCS shows MITF expression consistent with activation downstream of the
    EWSR1-ATF1 fusion. MITF is the master transcription factor of melanocyte
    lineage and activates genes involved in melanogenesis, cell survival, and
    proliferation. This explains the melanocytic phenotype despite soft tissue
    origin.
  evidence:
  - reference: PMID:11211309
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: "D5 immunoreactivity in clear cell sarcoma provides further evidence for melanocytic differentiation in this unusual tumor."
    explanation: Shows MITF protein expression in CCS, consistent with activation downstream of EWSR1-ATF1, but does not directly demonstrate transcriptional activation by the fusion.
  biological_processes:
  - preferred_term: regulation of gene expression
    modifier: ABNORMAL
    term:
      id: GO:0010468
      label: regulation of gene expression
  downstream:
  - target: Melanocytic Differentiation
    description: MITF activates melanocyte differentiation program
    evidence:
    - reference: PMID:11211309
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Immunoreactivity in a nuclear pattern for D5 was present in 8 of 12 (75%) tumors."
      explanation: Demonstrates MITF expression in the majority of CCS tumors, supporting the link from MITF activation to the melanocytic differentiation program.
- name: Melanocytic Differentiation
  description: >-
    Downstream of MITF activation, CCS cells express melanocytic markers including
    S100, HMB45, Melan-A, and tyrosinase. Melanin pigment may be present.
    However, unlike melanoma, CCS lacks UV-induced mutations and BRAF/NRAS
    alterations typical of cutaneous melanoma.
  evidence:
  - reference: PMID:11211309
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "S-100 protein expression was seen in all 12 cases that had clear cell sarcoma examined. HMB-45 staining was seen in 11 of 12 (92%) tumors. Focal Melan-A positivity was seen in 3 of 7 (43%) tumors."
    explanation: Directly supports expression of melanocytic markers (S-100, HMB45, Melan-A) in clear cell sarcoma, evidence of melanocytic differentiation.
  biological_processes:
  - preferred_term: cell differentiation
    modifier: ABNORMAL
    term:
      id: GO:0030154
      label: cell differentiation
histopathology:
- name: Malignant Melanoma of Soft Parts
  finding_term:
    preferred_term: Clear Cell Sarcoma of Soft Tissue
    term:
      id: NCIT:C3745
      label: Clear Cell Sarcoma of Soft Tissue
  frequency: VERY_FREQUENT
  description: Clear cell sarcoma is also known as malignant melanoma of soft parts.
  evidence:
  - reference: PMID:11211309
    reference_title: "Clear cell sarcoma shows immunoreactivity for microphthalmia transcription factor: further evidence for melanocytic differentiation."
    supports: SUPPORT
    snippet: "sarcoma (also known as malignant melanoma of soft parts)."
    explanation: Abstract notes clear cell sarcoma is also known as malignant melanoma of soft parts.

phenotypes:
- category: Musculoskeletal
  name: Soft Tissue Mass
  frequency: VERY_FREQUENT
  diagnostic: true
  description: >-
    A slowly growing deep soft tissue mass, most commonly in the foot, ankle,
    or knee region. The mass is often attached to tendons or aponeuroses.
    May be present for years before diagnosis.
  phenotype_term:
    preferred_term: Soft tissue neoplasm
    term:
      id: HP:0031459
      label: Soft tissue neoplasm
  evidence:
  - reference: PMID:40004764
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Clear Cell Sarcoma (CCS) of soft tissue is a rare and highly malignant neoplasm primarily affecting young adults, often presenting in the deep soft tissues of the extremities."
    explanation: Supports the typical clinical presentation of CCS as a deep soft tissue mass in the extremities.
- category: Musculoskeletal
  name: Localized Pain
  frequency: FREQUENT
  description: >-
    Pain and tenderness at the tumor site. The association with tendons may
    cause pain with movement.
  phenotype_term:
    preferred_term: localized pain
    term:
      id: HP:0012531
      label: Pain
- category: Systemic
  name: Lymph Node Involvement
  frequency: FREQUENT
  description: >-
    Regional lymph node metastasis occurs more commonly than in other soft
    tissue sarcomas, reflecting the melanocytic biology. Sentinel lymph node
    biopsy is often performed.
  phenotype_term:
    preferred_term: lymph node involvement
    term:
      id: HP:0002716
      label: Lymphadenopathy
  evidence:
  - reference: PMID:40004764
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "wide surgical excision remains the cornerstone for localized disease, with sentinel lymph node biopsy aiding in staging."
    explanation: The routine use of sentinel lymph node biopsy in CCS staging supports the propensity for lymph node involvement in this disease.
- category: Constitutional
  name: Weight Loss
  frequency: OCCASIONAL
  description: >-
    Weight loss is uncommon at presentation but may occur with advanced
    metastatic disease.
  phenotype_term:
    preferred_term: Weight loss
    term:
      id: HP:0001824
      label: Weight loss
biochemical:
- name: EWSR1-ATF1 Fusion Detection
  notes: >-
    RT-PCR or FISH detection of EWSR1-ATF1 (or EWSR1-CREB1) fusion is diagnostic.
    This fusion is essentially pathognomonic and distinguishes CCS from melanoma.
  evidence:
  - reference: PMID:40004764
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "CCS arises from connective tissues and is characterized by a distinct genetic hallmark: the EWSR1-ATF1 fusion resulting from t(12;22)(q13;q12) translocation. This genetic signature is absent in melanoma, making molecular diagnosis essential for accurate differentiation."
    explanation: Directly supports detection of the EWSR1-ATF1 fusion as a defining diagnostic biochemical feature distinguishing CCS from melanoma.
- name: Melanocytic Markers
  notes: >-
    Immunohistochemistry shows expression of melanocytic markers including
    S100, HMB45, Melan-A, and SOX10. Unlike melanoma, CCS lacks BRAF V600E
    mutations.
  evidence:
  - reference: PMID:11211309
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "S-100 protein expression was seen in all 12 cases that had clear cell sarcoma examined. HMB-45 staining was seen in 11 of 12 (92%) tumors. Focal Melan-A positivity was seen in 3 of 7 (43%) tumors."
    explanation: Directly supports the immunohistochemical detection of melanocytic markers (S-100, HMB-45, Melan-A) in CCS.
genetic:
- name: EWSR1-ATF1 Fusion
  association: Somatic Fusion Oncogene
  notes: >-
    The t(12;22)(q13;q12) translocation creates the EWSR1-ATF1 fusion in
    approximately 90% of cases. EWSR1-CREB1 fusion from t(2;22) occurs in
    a minority. These fusions are diagnostic and represent the primary
    oncogenic driver.
  evidence:
  - reference: PMID:40004764
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "CCS arises from connective tissues and is characterized by a distinct genetic hallmark: the EWSR1-ATF1 fusion resulting from t(12;22)(q13;q12) translocation."
    explanation: Directly supports the EWSR1-ATF1 fusion from t(12;22)(q13;q12) as the defining genetic driver of CCS.
  - reference: PMID:41749894
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "CCS is defined by EWSR1-ATF1/CREB1 fusions but exhibits low responsiveness to conventional chemotherapy."
    explanation: Supports both EWSR1-ATF1 and the alternative EWSR1-CREB1 fusion as genetic hallmarks of CCS.
treatments:
- name: Wide Surgical Resection
  description: >-
    Wide surgical excision with negative margins is the primary treatment.
    The tendency to arise near tendons and joints may complicate resection.
    Amputation may be necessary for large or recurrent tumors.
  treatment_term:
    preferred_term: surgical procedure
    term:
      id: MAXO:0000004
      label: surgical procedure
  evidence:
  - reference: PMID:40004764
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Therapeutically, wide surgical excision remains the cornerstone for localized disease"
    explanation: Directly supports wide surgical excision as the cornerstone treatment for localized CCS.
- name: Sentinel Lymph Node Biopsy
  description: >-
    Given the propensity for lymph node metastasis, sentinel lymph node biopsy
    is often performed for staging, similar to melanoma management.
  treatment_term:
    preferred_term: surgical procedure
    term:
      id: MAXO:0000004
      label: surgical procedure
  evidence:
  - reference: PMID:40004764
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "wide surgical excision remains the cornerstone for localized disease, with sentinel lymph node biopsy aiding in staging."
    explanation: Directly supports sentinel lymph node biopsy as a staging modality in CCS management.
- name: Radiation Therapy
  description: >-
    Adjuvant radiation may be used for close or positive margins or for
    unresectable disease. CCS is relatively radioresistant.
  treatment_term:
    preferred_term: radiation therapy
    term:
      id: MAXO:0000014
      label: radiation therapy
  evidence:
  - reference: PMID:40004764
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Adjuvant radiotherapy is considered in select cases, while chemotherapy has limited efficacy in metastatic settings."
    explanation: Supports the selective use of adjuvant radiotherapy in CCS management.
- name: Systemic Therapy
  description: >-
    CCS is generally chemoresistant. Doxorubicin-based regimens may be
    attempted for metastatic disease but response rates are low. Unlike
    melanoma, checkpoint inhibitors have limited efficacy.
  treatment_term:
    preferred_term: chemotherapy
    term:
      id: MAXO:0000647
      label: chemotherapy
    therapeutic_agent:
    - preferred_term: doxorubicin
      term:
        id: CHEBI:28748
        label: doxorubicin
  evidence:
  - reference: PMID:41749894
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "CCS is defined by EWSR1-ATF1/CREB1 fusions but exhibits low responsiveness to conventional chemotherapy."
    explanation: Directly supports the chemoresistant nature of CCS that limits the efficacy of systemic chemotherapy.
  - reference: PMID:40004764
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "chemotherapy has limited efficacy in metastatic settings."
    explanation: Supports the limited efficacy of chemotherapy in metastatic CCS, framing systemic therapy as palliative.
disease_term:
  preferred_term: clear cell sarcoma
  term:
    id: MONDO:0002926
    label: clear cell sarcoma

classifications:
  icdo_morphology:
    classification_value: Sarcoma
  harrisons_chapter:
  - classification_value: cancer
  - classification_value: solid tumor
references:
- reference: DOI:10.1007/s00432-018-2693-6
  title: 'The epidemiology and survivorship of clear cell sarcoma: a National Cancer Database (NCDB) review'
  found_in:
  - Clear_Cell_Sarcoma-deep-research-falcon.md
  findings:
  - statement: 'The epidemiology and survivorship of clear cell sarcoma: a National Cancer Database (NCDB) review'
    supporting_text: 'The epidemiology and survivorship of clear cell sarcoma: a National Cancer Database (NCDB) review'
- reference: DOI:10.1007/s00432-024-05980-3
  title: 'Prognostic factors in clear cell sarcoma: an analysis of soft tissue sarcoma in 43 cases'
  found_in:
  - Clear_Cell_Sarcoma-deep-research-falcon.md
  findings:
  - statement: 'Prognostic factors in clear cell sarcoma: an analysis of soft tissue sarcoma in 43 cases'
    supporting_text: Clear cell sarcoma (CCS) of tendons and aponeuroses and CCS-like malignant gastrointestinal neuroectodermal tumor/sarcoma (GINET) are characterized by frequent local and distant relapses, alongside with low efficacy of all systemic treatments.
    evidence:
    - reference: DOI:10.1007/s00432-024-05980-3
      reference_title: 'Prognostic factors in clear cell sarcoma: an analysis of soft tissue sarcoma in 43 cases'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Clear cell sarcoma (CCS) of tendons and aponeuroses and CCS-like malignant gastrointestinal neuroectodermal tumor/sarcoma (GINET) are characterized by frequent local and distant relapses, alongside with low efficacy of all systemic treatments.
      explanation: Deep research cited this publication as relevant literature for Clear Cell Sarcoma.
- reference: DOI:10.1038/s41416-023-02222-0
  title: 'Functional genomics of human clear cell sarcoma: genomic, transcriptomic and chemical biology landscape for clear cell sarcoma'
  found_in:
  - Clear_Cell_Sarcoma-deep-research-falcon.md
  findings:
  - statement: 'Functional genomics of human clear cell sarcoma: genomic, transcriptomic and chemical biology landscape for clear cell sarcoma'
    supporting_text: 'Functional genomics of human clear cell sarcoma: genomic, transcriptomic and chemical biology landscape for clear cell sarcoma'
- reference: DOI:10.1097/pas.0b013e31825485c5
  title: Tumors With EWSR1-CREB1 and EWSR1-ATF1 Fusions
  found_in:
  - Clear_Cell_Sarcoma-deep-research-falcon.md
  findings:
  - statement: Tumors With EWSR1-CREB1 and EWSR1-ATF1 Fusions
    supporting_text: Tumors With EWSR1-CREB1 and EWSR1-ATF1 Fusions
- reference: DOI:10.1158/2767-9764.crc-22-0518
  title: Targeting the Clear Cell Sarcoma Oncogenic Driver Fusion Gene <i>EWSR1::ATF1</i> by HDAC Inhibition
  found_in:
  - Clear_Cell_Sarcoma-deep-research-falcon.md
  findings:
  - statement: Clear cell sarcoma (CCS), a rare but extremely aggressive malignancy with no effective therapy, is characterized by the expression of the oncogenic driver fusion gene EWSR1::ATF1.
    supporting_text: Clear cell sarcoma (CCS), a rare but extremely aggressive malignancy with no effective therapy, is characterized by the expression of the oncogenic driver fusion gene EWSR1::ATF1.
    evidence:
    - reference: DOI:10.1158/2767-9764.crc-22-0518
      reference_title: Targeting the Clear Cell Sarcoma Oncogenic Driver Fusion Gene <i>EWSR1::ATF1</i> by HDAC Inhibition
      supports: SUPPORT
      evidence_source: OTHER
      snippet: Clear cell sarcoma (CCS), a rare but extremely aggressive malignancy with no effective therapy, is characterized by the expression of the oncogenic driver fusion gene EWSR1::ATF1.
      explanation: Deep research cited this publication as relevant literature for Clear Cell Sarcoma.
- reference: DOI:10.3390/cancers15245750
  title: EWSR1::ATF1 Orchestrates the Clear Cell Sarcoma Transcriptome in Human Tumors and a Mouse Genetic Model
  found_in:
  - Clear_Cell_Sarcoma-deep-research-falcon.md
  findings:
  - statement: Clear cell sarcoma (CCS) is a rare, aggressive malignancy that most frequently arises in the soft tissues of the extremities.
    supporting_text: Clear cell sarcoma (CCS) is a rare, aggressive malignancy that most frequently arises in the soft tissues of the extremities.
    evidence:
    - reference: DOI:10.3390/cancers15245750
      reference_title: EWSR1::ATF1 Orchestrates the Clear Cell Sarcoma Transcriptome in Human Tumors and a Mouse Genetic Model
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: Clear cell sarcoma (CCS) is a rare, aggressive malignancy that most frequently arises in the soft tissues of the extremities.
      explanation: Deep research cited this publication as relevant literature for Clear Cell Sarcoma.
- reference: DOI:10.3390/ijms252413693
  title: 'EWSR1::ATF1 Translocation: A Common Tumor Driver of Distinct Human Neoplasms'
  found_in:
  - Clear_Cell_Sarcoma-deep-research-falcon.md
  findings:
  - statement: Cancer is among the leading causes of mortality in developed countries due to limited available therapeutic modalities and high rate of morbidity.
    supporting_text: Cancer is among the leading causes of mortality in developed countries due to limited available therapeutic modalities and high rate of morbidity.
    evidence:
    - reference: DOI:10.3390/ijms252413693
      reference_title: 'EWSR1::ATF1 Translocation: A Common Tumor Driver of Distinct Human Neoplasms'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Cancer is among the leading causes of mortality in developed countries due to limited available therapeutic modalities and high rate of morbidity.
      explanation: Deep research cited this publication as relevant literature for Clear Cell Sarcoma.
- reference: DOI:10.3390/jcm14041233
  title: 'Clear Cell Sarcoma (CCS) of the Soft Tissue: An Update Narrative Review with Emphasis on the Utility of PRAME in Differential Diagnosis'
  found_in:
  - Clear_Cell_Sarcoma-deep-research-falcon.md
  findings:
  - statement: Clear Cell Sarcoma (CCS) of soft tissue is a rare and highly malignant neoplasm primarily affecting young adults, often presenting in the deep soft tissues of the extremities.
    supporting_text: Clear Cell Sarcoma (CCS) of soft tissue is a rare and highly malignant neoplasm primarily affecting young adults, often presenting in the deep soft tissues of the extremities.
    evidence:
    - reference: DOI:10.3390/jcm14041233
      reference_title: 'Clear Cell Sarcoma (CCS) of the Soft Tissue: An Update Narrative Review with Emphasis on the Utility of PRAME in Differential Diagnosis'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Clear Cell Sarcoma (CCS) of soft tissue is a rare and highly malignant neoplasm primarily affecting young adults, often presenting in the deep soft tissues of the extremities.
      explanation: Deep research cited this publication as relevant literature for Clear Cell Sarcoma.

📚

References & Deep Research

References

8

DOI:10.1007/s00432-018-2693-6

The epidemiology and survivorship of clear cell sarcoma: a National Cancer Database (NCDB) review

1 finding

The epidemiology and survivorship of clear cell sarcoma: a National Cancer Database (NCDB) review

"The epidemiology and survivorship of clear cell sarcoma: a National Cancer Database (NCDB) review"

DOI:10.1007/s00432-024-05980-3

Prognostic factors in clear cell sarcoma: an analysis of soft tissue sarcoma in 43 cases

1 finding

Prognostic factors in clear cell sarcoma: an analysis of soft tissue sarcoma in 43 cases

"Clear cell sarcoma (CCS) of tendons and aponeuroses and CCS-like malignant gastrointestinal neuroectodermal tumor/sarcoma (GINET) are characterized by frequent local and distant relapses, alongside with low efficacy of all systemic treatments."

Show evidence (1 reference)

DOI:10.1007/s00432-024-05980-3 SUPPORT Human Clinical

"Clear cell sarcoma (CCS) of tendons and aponeuroses and CCS-like malignant gastrointestinal neuroectodermal tumor/sarcoma (GINET) are characterized by frequent local and distant relapses, alongside with low efficacy of all systemic treatments."

Deep research cited this publication as relevant literature for Clear Cell Sarcoma.

DOI:10.1038/s41416-023-02222-0

Functional genomics of human clear cell sarcoma: genomic, transcriptomic and chemical biology landscape for clear cell sarcoma

1 finding

Functional genomics of human clear cell sarcoma: genomic, transcriptomic and chemical biology landscape for clear cell sarcoma

"Functional genomics of human clear cell sarcoma: genomic, transcriptomic and chemical biology landscape for clear cell sarcoma"

DOI:10.1097/pas.0b013e31825485c5

Tumors With EWSR1-CREB1 and EWSR1-ATF1 Fusions

1 finding

Tumors With EWSR1-CREB1 and EWSR1-ATF1 Fusions

"Tumors With EWSR1-CREB1 and EWSR1-ATF1 Fusions"

DOI:10.1158/2767-9764.crc-22-0518

Targeting the Clear Cell Sarcoma Oncogenic Driver Fusion Gene <i>EWSR1::ATF1</i> by HDAC Inhibition

1 finding

Clear cell sarcoma (CCS), a rare but extremely aggressive malignancy with no effective therapy, is characterized by the expression of the oncogenic driver fusion gene EWSR1::ATF1.

"Clear cell sarcoma (CCS), a rare but extremely aggressive malignancy with no effective therapy, is characterized by the expression of the oncogenic driver fusion gene EWSR1::ATF1."

Show evidence (1 reference)

DOI:10.1158/2767-9764.crc-22-0518 SUPPORT Other

"Clear cell sarcoma (CCS), a rare but extremely aggressive malignancy with no effective therapy, is characterized by the expression of the oncogenic driver fusion gene EWSR1::ATF1."

Deep research cited this publication as relevant literature for Clear Cell Sarcoma.

DOI:10.3390/cancers15245750

EWSR1::ATF1 Orchestrates the Clear Cell Sarcoma Transcriptome in Human Tumors and a Mouse Genetic Model

1 finding

Clear cell sarcoma (CCS) is a rare, aggressive malignancy that most frequently arises in the soft tissues of the extremities.

"Clear cell sarcoma (CCS) is a rare, aggressive malignancy that most frequently arises in the soft tissues of the extremities."

Show evidence (1 reference)

DOI:10.3390/cancers15245750 SUPPORT Model Organism

"Clear cell sarcoma (CCS) is a rare, aggressive malignancy that most frequently arises in the soft tissues of the extremities."

Deep research cited this publication as relevant literature for Clear Cell Sarcoma.

DOI:10.3390/ijms252413693

EWSR1::ATF1 Translocation: A Common Tumor Driver of Distinct Human Neoplasms

1 finding

Cancer is among the leading causes of mortality in developed countries due to limited available therapeutic modalities and high rate of morbidity.

"Cancer is among the leading causes of mortality in developed countries due to limited available therapeutic modalities and high rate of morbidity."

Show evidence (1 reference)

DOI:10.3390/ijms252413693 SUPPORT Human Clinical

"Cancer is among the leading causes of mortality in developed countries due to limited available therapeutic modalities and high rate of morbidity."

Deep research cited this publication as relevant literature for Clear Cell Sarcoma.

DOI:10.3390/jcm14041233

Clear Cell Sarcoma (CCS) of the Soft Tissue: An Update Narrative Review with Emphasis on the Utility of PRAME in Differential Diagnosis

1 finding

Clear Cell Sarcoma (CCS) of soft tissue is a rare and highly malignant neoplasm primarily affecting young adults, often presenting in the deep soft tissues of the extremities.

"Clear Cell Sarcoma (CCS) of soft tissue is a rare and highly malignant neoplasm primarily affecting young adults, often presenting in the deep soft tissues of the extremities."

Show evidence (1 reference)

DOI:10.3390/jcm14041233 SUPPORT Human Clinical

"Clear Cell Sarcoma (CCS) of soft tissue is a rare and highly malignant neoplasm primarily affecting young adults, often presenting in the deep soft tissues of the extremities."

Deep research cited this publication as relevant literature for Clear Cell Sarcoma.

Deep Research

1

Falcon ▸

1. Disease Information

Edison Scientific Literature 22 citations 2026-04-05T14:07:25.487255

1. Disease Information

1.1 Concise overview (current understanding)

Clear cell sarcoma (CCS) is a rare, aggressive malignant soft-tissue sarcoma that typically arises in deep soft tissues associated with tendons/aponeuroses and most often occurs in the extremities (notably lower extremity/foot–ankle region). It shows melanocytic differentiation and is a major diagnostic mimic of malignant melanoma. (cazzato2025clearcellsarcoma pages 1-2, thway2012tumorswithewsr1creb1 pages 3-5, gonzaga2018theepidemiologyand pages 1-2, ozenberger2023ewsr1atf1orchestratesthe pages 1-2)

Direct abstract quote (molecularly defining feature): “Clear cell sarcoma (CCS)… is characterized by the expression of the oncogenic driver fusion gene EWSR1::ATF1.” (Mae et al., 2023, Cancer Research Communications, published Jul 2023, https://doi.org/10.1158/2767-9764.crc-22-0518) (mae2023targetingtheclear pages 1-2)

1.2 Key identifiers

The following identifiers were not captured in the retrieved excerpts, so cannot be reliably asserted here: - OMIM / Orphanet / ICD-10 / ICD-11 / MONDO: not available in current evidence. - MeSH: ClinicalTrials.gov condition browse lists MeSH term “Sarcoma, Clear Cell” (MeSH ID D018227) for this condition. (NCT05963035 chunk 1)

1.3 Synonyms / alternative names

Clear cell sarcoma of soft tissue (CCS) (cazzato2025clearcellsarcoma pages 1-2)
Clear cell sarcoma of tendons and aponeuroses (grothues2024prognosticfactorsin pages 1-2)
“Malignant melanoma of soft parts” / “soft tissue melanoma” (historical) (mae2023targetingtheclear pages 1-2, gonzaga2018theepidemiologyand pages 1-2)

1.4 Evidence source type

Most disease-level definitions and management statements in this report derive from aggregated resources (reviews), registry/cohort analyses, and clinical trial registry entries rather than single-patient EHR-derived sources. (cazzato2025clearcellsarcoma pages 1-2, gonzaga2018theepidemiologyand pages 1-2, ozenberger2023ewsr1atf1orchestratesthe pages 1-2, NCT05963035 chunk 1)

2. Etiology

2.1 Disease causal factors (genetic/mechanistic)

CCS is primarily a fusion-driven sarcoma, most commonly defined by EWSR1::ATF1 (EWSR1 fused to ATF1), usually arising from t(12;22)(q13;q12); rarer variants include EWSR1::CREB1 or EWSR1::CREM. (mae2023targetingtheclear pages 1-2, ozenberger2023ewsr1atf1orchestratesthe pages 1-2)

Direct abstract quote (fusion defines and drives disease): “It is defined and driven by expression of… translocation-generated fusion oncogenes, the most common of which is EWSR1::ATF1.” (Ozenberger et al., 2023, Cancers, published Dec 2023, https://doi.org/10.3390/cancers15245750) (ozenberger2023ewsr1atf1orchestratesthe pages 1-2)

Frequency of hallmark fusion: One 2023 genomic/functional review states: “Nearly 90% of CCS harbor an EWSR1-ATF1 translocation-mediated fusion gene, although EWSR1-CREB1 is also observed.” (Rasmussen et al., 2023, British Journal of Cancer, published Mar 2023, https://doi.org/10.1038/s41416-023-02222-0) (rasmussen2023functionalgenomicsof pages 1-2)

2.2 Risk factors

No robust environmental/behavioral risk factors were identified in the retrieved evidence. Available evidence emphasizes oncogenic fusion as the major causal event. (rasmussen2023functionalgenomicsof pages 1-2, ozenberger2023ewsr1atf1orchestratesthe pages 1-2)

2.3 Protective factors / gene–environment interaction

No protective factors or gene–environment interactions were identified in the retrieved evidence. (rasmussen2023functionalgenomicsof pages 1-2)

3. Phenotypes

3.1 Core clinical phenotype spectrum

Common presentations include a deep soft-tissue mass in an extremity and association with tendons/aponeuroses. Pain may be present (one review describes “a painful, rapidly growing mass” in typical locations). (bianco2024ewsr1atf1translocationa pages 12-13, gonzaga2018theepidemiologyand pages 1-2)

Typical sites / demographics (examples): - CCS “arises in muscle compartments, tendons, or aponeuroses, most frequently in the extremities.” (Ozenberger et al., 2023) (ozenberger2023ewsr1atf1orchestratesthe pages 1-2) - In an NCDB cohort, lower limb/hip was the most frequent primary site (53%). (Gonzaga et al., 2018, https://doi.org/10.1007/s00432-018-2693-6) (gonzaga2018theepidemiologyand pages 1-2)

3.2 Suggested HPO terms (non-exhaustive; based on clinical descriptions)

Because the retrieved evidence is not structured as HPO annotations, the following are suggested mappings from described clinical manifestations: - Soft tissue mass → Soft tissue neoplasm (candidate HPO mapping; specific HPO ID not available in evidence) - Painful mass → Pain (candidate) - Local recurrence / metastasis → Neoplasm metastasis (candidate)

Note: Exact HPO IDs require ontology lookup not performed in this run.

3.3 Quality-of-life impact

Formal QoL instruments (e.g., EQ-5D/SF-36) were not reported in the retrieved CCS-specific papers; however, QoL is included as an outcome in at least one CCS immunotherapy trial protocol (EORTC QLQ-C30 and EQ-5D). (NCT04274023 chunk 1)

4. Genetic / Molecular Information

4.1 Causal genes / chromosomal abnormalities

EWSR1::ATF1 fusion (EWSR1 and ATF1 genes) from t(12;22)(q13;q12) is the central hallmark for CCS. (mae2023targetingtheclear pages 1-2, ozenberger2023ewsr1atf1orchestratesthe pages 1-2)
Rarer: EWSR1::CREB1 and EWSR1::CREM. (ozenberger2023ewsr1atf1orchestratesthe pages 1-2)

4.2 Pathogenic variant class

The dominant pathogenic event is a structural rearrangement generating an oncogenic fusion transcription factor (chimeric transcriptional regulator). (mae2023targetingtheclear pages 1-2, ozenberger2023ewsr1atf1orchestratesthe pages 1-2)

4.3 Functional consequences / downstream programs

Mechanistically, evidence supports that EWSR1::ATF1 reprograms transcription and is sufficient to initiate sarcomagenesis in model systems. (ozenberger2023ewsr1atf1orchestratesthe pages 1-2)

Direct abstract quote (transcriptional reprogramming): “The EWSR1::ATF1 fusion oncoprotein reprograms transcription.” (Ozenberger et al., 2023) (ozenberger2023ewsr1atf1orchestratesthe pages 1-2)

4.4 Additional recurrent genomic features (from functional genomics)

A 2023 functional genomics study reports frequent copy gains involving MITF and MYC loci in human CCS samples (e.g., MYC gain in 62% and MITF gain in 55% of a set of tumors described in the excerpt). (rasmussen2023functionalgenomicsof pages 1-2)

5. Environmental Information

No specific environmental/lifestyle/infectious contributors were identified in the retrieved evidence. CCS is primarily discussed as a fusion-oncogene-driven malignancy. (rasmussen2023functionalgenomicsof pages 1-2, ozenberger2023ewsr1atf1orchestratesthe pages 1-2)

6. Mechanism / Pathophysiology

6.1 High-level causal chain (fusion → transcriptional/epigenetic rewiring → phenotype)

Chromosomal translocation generates EWSR1::ATF1 fusion. (mae2023targetingtheclear pages 1-2, ozenberger2023ewsr1atf1orchestratesthe pages 1-2)
Fusion functions as an aberrant transcriptional regulator that reprograms transcription and sustains tumor state. (ozenberger2023ewsr1atf1orchestratesthe pages 1-2)
Tumor develops melanocytic differentiation (shared IHC markers with melanoma) and demonstrates aggressive behavior with local recurrence and metastasis risk. (thway2012tumorswithewsr1creb1 pages 3-5, gonzaga2018theepidemiologyand pages 1-2)

6.2 Epigenetic/transcriptional dependencies and therapeutic implications (recent)

A 2023 study used high-throughput screening and found that HDAC inhibition can suppress the fusion program.

Direct abstract quote (screening and lead drug): “we performed a high-throughput drug screening, finding that the histone deacetylase inhibitor vorinostat exerted an antiproliferation effect with the reduced expression of EWSR1::ATF1.” (Mae et al., 2023, https://doi.org/10.1158/2767-9764.crc-22-0518) (mae2023targetingtheclear pages 1-2)

6.3 Suggested GO / CL terms (conceptual; require ontology lookup)

Based on the evidence that CCS is fusion-transcription-factor driven and involves melanocytic differentiation markers: - GO Biological Process (candidate): regulation of transcription, chromatin organization, melanocyte differentiation - CL (candidate): neural crest-derived cell lineages (proposed by epigenetic/3D regulation studies; not fully extracted here)

7. Anatomical Structures Affected

7.1 Organ/tissue level

Predominantly deep soft tissue of extremities; commonly near tendons and aponeuroses. (cazzato2025clearcellsarcoma pages 1-2, thway2012tumorswithewsr1creb1 pages 3-5, gonzaga2018theepidemiologyand pages 1-2, ozenberger2023ewsr1atf1orchestratesthe pages 1-2)

7.2 Suggested UBERON terms (conceptual)

Extremity soft tissue; tendon; aponeurosis (exact UBERON IDs not retrieved).

8. Temporal Development

8.1 Onset

Typically affects adolescents/young adults but can occur across a broad range. Reported mean age 22 (range 2–83) in one 2023 review; median age 39 in NCDB (1973–2014 cohort analysis); median age 42 in a 2024 single-center cohort. (rasmussen2023functionalgenomicsof pages 1-2, gonzaga2018theepidemiologyand pages 1-2, grothues2024prognosticfactorsin pages 1-2)

8.2 Progression

Evidence emphasizes frequent local recurrence and late metastasis, with poor long-term survival in many cohorts. (rasmussen2023functionalgenomicsof pages 1-2, gonzaga2018theepidemiologyand pages 1-2, grothues2024prognosticfactorsin pages 1-2)

9. Inheritance and Population

9.1 Epidemiology (key quantitative data)

CCS is very rare. One paper states it is “less than one percent of soft-tissue sarcomas” and reports “fewer than 100 cases… annually in the United States.” (Ozenberger et al., 2023) (ozenberger2023ewsr1atf1orchestratesthe pages 1-2)

A SEER-based analysis reported population-adjusted incidence range 0.012/100,000 to 0.027/100,000 (2000–2019). (gonzaga2018theepidemiologyand pages 1-2)

9.2 Demographics

NCDB review: median age 39, sexes approximately equal, and race distribution 78% Caucasian and 15% Black. (gonzaga2018theepidemiologyand pages 1-2)

9.3 Inheritance

CCS is not presented as an inherited Mendelian disorder in the retrieved evidence; it is driven by a somatic fusion. Germline predisposition was not identified here. (ozenberger2023ewsr1atf1orchestratesthe pages 1-2)

10. Diagnostics

10.1 Pathology and immunohistochemistry

CCS is a melanoma mimic; classic IHC profile overlaps melanoma.

From a high-citation pathology review: “most CCSs show diffuse S100 protein, HMB45, MelanA and MiTF expression and are immunohistochemically indistinguishable from melanoma.” (Thway & Fisher, 2012, Am J Surg Pathol, https://doi.org/10.1097/pas.0b013e31825485c5) (thway2012tumorswithewsr1creb1 pages 3-5)

10.2 Molecular diagnostics

Molecular confirmation is emphasized for distinguishing CCS from melanoma:

Direct abstract quote: “the use of fluorescence in situ hybridization (FISH) or reverse transcription polymerase chain reaction (RT-PCR) is essential for diagnosis and distinguishing CCS from primary and/or metastatic melanoma.” (Gonzaga et al., 2018, https://doi.org/10.1007/s00432-018-2693-6) (gonzaga2018theepidemiologyand pages 1-2)

10.3 Differential diagnosis

Primary differential is malignant melanoma due to shared morphology and melanocytic markers; molecular demonstration of EWSR1 fusion is key. (cazzato2025clearcellsarcoma pages 1-2, thway2012tumorswithewsr1creb1 pages 3-5, gonzaga2018theepidemiologyand pages 1-2)

10.4 Emerging/adjunct markers and tools

Recent narrative review emphasizes PRAME as an adjunct marker in differential diagnosis with melanoma, while noting PRAME positivity is relatively rare in CCS. (cazzato2025clearcellsarcoma pages 1-2, cazzato2025clearcellsarcoma pages 8-10)

10.5 Imaging and staging innovations (real-world implementation)

A prospective diagnostic study is evaluating melanin-targeted PET imaging.

NCT05963035 (posted 2023-07-27; start 2023-06-21): prospective study of 18F-PFPN PET/MR versus 18F-FDG for diagnosis and staging in CCS of soft tissue (planned n=10). (ClinicalTrials.gov record) (NCT05963035 chunk 1)

11. Outcomes / Prognosis

11.1 Survival statistics

Multiple sources converge on poor long-term outcomes.

A widely repeated summary: 5-year ~50%, 10-year ~38% overall survival. (mae2023targetingtheclear pages 1-2, bianco2024ewsr1atf1translocationa pages 12-13, gonzaga2018theepidemiologyand pages 1-2, ozenberger2023ewsr1atf1orchestratesthe pages 1-2)
A 2024 single-center cohort (43 CCS/GINET patients) reported: “median follow-up of 35mo and a 5y-OS-rate of 42%.” (Grothues et al., 2024, https://doi.org/10.1007/s00432-024-05980-3) (grothues2024prognosticfactorsin pages 1-2)

11.2 Metastasis and lymphatic spread (quantitative)

2024 cohort: “18.6% of patients showed lymphatic spread and 20.9% distant metastases.” (Grothues et al., 2024) (grothues2024prognosticfactorsin pages 1-2)
NCDB review summarizes that lymph node metastases are unusually frequent for STS (estimated 12–43% across prior literature) and reports 15% distant organ metastases in the cohort (lung most common 4%). (gonzaga2018theepidemiologyand pages 1-2)

11.3 Prognostic factors (recent quantitative evidence)

Initial metastatic disease is strongly adverse: “Presence of initial M+ was associated with a dismal survival of 1.4 years (M+) vs 7.1 years (M0; p < .001).” (Grothues et al., 2024) (grothues2024prognosticfactorsin pages 1-2)
Completeness of surgery matters in localized disease: “Final R0 status correlated significantly… with longer survival… (N0M0, 5-yr OS 0% vs 64% [R+ vs R0]).” (Grothues et al., 2024) (grothues2024prognosticfactorsin pages 1-2)

12. Treatment

12.1 Current standard of care / real-world implementation

Across reviews and cohort analyses, surgery with negative margins is the main curative-intent treatment for localized CCS. (cazzato2025clearcellsarcoma pages 1-2, gonzaga2018theepidemiologyand pages 1-2, grothues2024prognosticfactorsin pages 1-2)

NCDB treatment patterns: surgery 83%, radiation 34%, chemotherapy 20%. (gonzaga2018theepidemiologyand pages 1-2)

12.2 Radiotherapy and chemotherapy

Conventional radiotherapy and chemotherapy are often described as having limited benefit.

“Traditional chemo- and radiotherapies have minimal benefit in CCS.” (Bianco et al., 2024, https://doi.org/10.3390/ijms252413693) (bianco2024ewsr1atf1translocationa pages 12-13)
2024 cohort: “Radiation and systemic treatment had limited antitumor effects…” (Grothues et al., 2024) (grothues2024prognosticfactorsin pages 1-2)

12.3 Investigational and emerging strategies (2023–2024 emphasis)

Epigenetic/transcriptional targeting is supported by preclinical evidence: - HDAC inhibitor vorinostat suppressing EWSR1::ATF1 and inhibiting proliferation in CCS models. (mae2023targetingtheclear pages 1-2)

Targeted therapy and immunotherapy are being explored due to lack of effective systemic options in metastatic disease. (cazzato2025clearcellsarcoma pages 8-10, grothues2024prognosticfactorsin pages 1-2)

12.4 Clinical trials (selected, with real-world status)

NCT04593758 (posted 2020-10-20; completion 2023-03-09): devimistat (CPI-613) + hydroxychloroquine for relapsed/refractory CCS; phase I/II; n=16; completed. (NCT04593758 chunk 1)
NCT04274023 (posted 2020-02-18; status updated 2024-02-01): anti-PD-1 TSR-042 in advanced CCS; phase II; terminated due to enrollment difficulty; n=3. (NCT04274023 chunk 1)
NCT03132155 (results posted 2024-05-24): AMG 337 for advanced/metastatic CCS with EWSR1-ATF1 fusion; phase II; “terminated due to lack of therapeutic effect”; n=8. (NCT03132155 chunk 1)
NCT04458922 (results first posted 2023-10-23): atezolizumab phase II study in CCS/chondrosarcoma; includes tumor microenvironment correlatives (CD8 and PD-1/PD-L1); active not recruiting; n=27 total. (NCT04458922 chunk 1)

MAXO term suggestions (conceptual): - Surgical excision; radiotherapy; systemic chemotherapy; immune checkpoint inhibitor therapy; targeted therapy (MET inhibition); PET imaging (diagnostic). (Trial and review evidence supports these intervention classes) (cazzato2025clearcellsarcoma pages 8-10, NCT05963035 chunk 1, NCT04274023 chunk 1, NCT04458922 chunk 1)

13. Prevention

No established primary prevention strategies were identified in the retrieved evidence; CCS is rare and primarily defined by a somatic fusion event. Secondary prevention is effectively early detection and expert referral for accurate diagnosis and complete surgical management. (gonzaga2018theepidemiologyand pages 1-2, grothues2024prognosticfactorsin pages 1-2)

14. Other Species / Natural Disease

No comparative veterinary/natural disease evidence was retrieved in this run.

15. Model Organisms

Evidence in this run supports the existence of mouse genetic models and preclinical approaches centered on EWSR1::ATF1-driven tumor programs (including studies describing initiation of sarcomagenesis and transcriptome recapitulation). (ozenberger2023ewsr1atf1orchestratesthe pages 1-2)

Structured summary table (for knowledge base ingestion)

The following table consolidates key facts (definition, epidemiology, diagnostics, prognosis, therapies, and NCT trials) into a single scaffold.

Domain	Item	Key details	Source/year	Citation
Definition / synonyms / hallmark fusion	Disease overview	Rare, aggressive soft-tissue sarcoma with melanocytic differentiation; classically arises in tendons/aponeuroses or deep soft tissue of extremities; historically confused with melanoma/“melanoma of soft parts.”	Reviews and cohort summaries, 2018-2025	(cazzato2025clearcellsarcoma pages 1-2, thway2012tumorswithewsr1creb1 pages 3-5, mae2023targetingtheclear pages 1-2, gonzaga2018theepidemiologyand pages 1-2, ozenberger2023ewsr1atf1orchestratesthe pages 1-2)
Definition / synonyms / hallmark fusion	Common synonyms	Clear cell sarcoma of soft tissue; clear-cell sarcoma of tendons and aponeuroses; malignant melanoma of soft parts / soft tissue melanoma (historical).	2018, 2022, 2025	(mae2023targetingtheclear pages 1-2, gonzaga2018theepidemiologyand pages 1-2)
Definition / synonyms / hallmark fusion	Hallmark molecular event	Definitional/pathognomonic fusion is usually EWSR1::ATF1 from t(12;22)(q13;q12); EWSR1::CREB1 is a rarer alternative; EWSR1::CREM reported rarely.	2023-2025	(cazzato2025clearcellsarcoma pages 1-2, rasmussen2023functionalgenomicsof pages 1-2, mae2023targetingtheclear pages 1-2, ozenberger2023ewsr1atf1orchestratesthe pages 1-2)
Epidemiology / clinical stats	Rarity	Accounts for <1% of soft-tissue sarcomas; fewer than 100 cases/year in the US reported in one review/modeling paper.	2023	(ozenberger2023ewsr1atf1orchestratesthe pages 1-2)
Epidemiology / clinical stats	Incidence	SEER 2000-2019: population-adjusted incidence ranged 0.012-0.027 per 100,000; annual percent change 0.561%.	Wang 2025	(gonzaga2018theepidemiologyand pages 1-2)
Epidemiology / clinical stats	Age distribution	Mean age reported as 22 years (range 2-83) in one genomic review; NCDB median age 39 years; another 2024 cohort median age 42 years.	2018, 2023, 2024	(rasmussen2023functionalgenomicsof pages 1-2, gonzaga2018theepidemiologyand pages 1-2)
Epidemiology / clinical stats	Sex / race	NCDB review: males and females approximately equally affected; race distribution 78% Caucasian, 15% Black.	Gonzaga 2018	(gonzaga2018theepidemiologyand pages 1-2)
Epidemiology / clinical stats	Primary location	Lower limb/hip 53% in NCDB; distant extremities affected in 72.5% in a 2024 cohort; commonly foot/ankle/shin, tendons and aponeuroses.	2018, 2024, 2024 review	(thway2012tumorswithewsr1creb1 pages 3-5, gonzaga2018theepidemiologyand pages 1-2, ozenberger2023ewsr1atf1orchestratesthe pages 1-2)
Epidemiology / clinical stats	Metastasis at diagnosis	Up to 30% may present with metastasis at diagnosis (review); NCDB reported 15% with distant organ metastases, lung most common (4%); 2024 cohort reported 20.9% distant metastases at presentation.	2018, 2023, 2024	(rasmussen2023functionalgenomicsof pages 1-2, gonzaga2018theepidemiologyand pages 1-2)
Epidemiology / clinical stats	Lymph node spread	Lymph node metastases estimated 12-43% in prior literature summarized by NCDB review; another study cited 16.8% LNM for clear cell sarcoma among STS of head/neck/extremities; 2024 cohort reported 18.6% lymphatic spread.	2018, 2022, 2024	(gonzaga2018theepidemiologyand pages 1-2)
Epidemiology / clinical stats	Survival	Frequently cited OS rates: 5-year ~50% and 10-year ~38%; broader review range 5-year 47-67%, 10-year 33%, 20-year 10%; SEER 2000-2019 survival 1-year 78.4%, 3-year 62.0%, 5-year 57.1%.	2023, 2025	(rasmussen2023functionalgenomicsof pages 1-2, mae2023targetingtheclear pages 1-2, bianco2024ewsr1atf1translocationa pages 12-13, gonzaga2018theepidemiologyand pages 1-2, ozenberger2023ewsr1atf1orchestratesthe pages 1-2)
Epidemiology / clinical stats	Prognostic factors	Worse outcomes associated with metastases, larger tumors (>4 cm in SEER), trunk location, and non-R0 resection; in localized CCS, 5-year OS 0% vs 64% for R+ vs R0 in one 2024 cohort.	2018, 2024, 2025	(gonzaga2018theepidemiologyand pages 1-2)
Diagnostics	Histopathology	Lobular/nested/organoid growth of spindle-to-epithelioid cells with clear to amphophilic cytoplasm; melanin may be present; often low mitotic activity.	2012, 2025	(cazzato2025clearcellsarcoma pages 1-2, thway2012tumorswithewsr1creb1 pages 3-5)
Diagnostics	Core IHC markers	Commonly positive: S100, HMB45, MelanA, MiTF; tyrosinase also noted in fusion-associated melanocytic program. These markers make CCS immunophenotypically similar to melanoma.	2012, 2024	(thway2012tumorswithewsr1creb1 pages 3-5, bianco2024ewsr1atf1translocationa pages 12-13)
Diagnostics	Emerging / adjunct IHC	PRAME may help in differential diagnosis versus melanoma, but expression in CCS is relatively rare / imperfectly specific.	2023-2025	(cazzato2025clearcellsarcoma pages 1-2, cazzato2025clearcellsarcoma pages 8-10)
Diagnostics	Molecular confirmation	Diagnosis commonly requires FISH, RT-PCR, or RNA-based molecular methods to identify EWSR1 rearrangement/fusion and distinguish CCS from melanoma.	2018, trial protocols	(gonzaga2018theepidemiologyand pages 1-2, NCT03132155 chunk 1)
Diagnostics	Differential diagnosis	Main differential is malignant melanoma due to overlapping melanocytic morphology/IHC; molecular demonstration of EWSR1::ATF1 or related fusion is key discriminator.	2018-2025	(cazzato2025clearcellsarcoma pages 1-2, thway2012tumorswithewsr1creb1 pages 3-5, cazzato2025clearcellsarcoma pages 8-10, gonzaga2018theepidemiologyand pages 1-2)
Standard treatment	Localized disease	Wide/radical surgical excision with negative margins is the treatment cornerstone; expert multidisciplinary management recommended.	2018-2025	(cazzato2025clearcellsarcoma pages 1-2, mae2023targetingtheclear pages 1-2, cazzato2025clearcellsarcoma pages 8-10, gonzaga2018theepidemiologyand pages 1-2)
Standard treatment	Radiotherapy	Used selectively/adjuvantly, especially when recurrence risk is high or margins are inadequate; antitumor effect often limited in CCS-specific cohorts.	2012, 2024, 2025	(thway2012tumorswithewsr1creb1 pages 3-5, cazzato2025clearcellsarcoma pages 8-10, gonzaga2018theepidemiologyand pages 1-2)
Standard treatment	Chemotherapy	Conventional / classical chemotherapy has limited efficacy and CCS is often described as chemo-resistant.	2022-2025	(cazzato2025clearcellsarcoma pages 1-2, mae2023targetingtheclear pages 1-2, bianco2024ewsr1atf1translocationa pages 12-13, cazzato2025clearcellsarcoma pages 8-10)
Standard treatment	Nodal staging consideration	Sentinel lymph node biopsy may aid staging because of propensity for lymphatic spread; radical lymphadenectomy considered if nodal metastases present.	2024 review	(cazzato2025clearcellsarcoma pages 8-10)
Investigational therapy / trials	Epigenetic targeting	Preclinical 2023 work identified vorinostat (HDAC inhibitor) suppressing EWSR1::ATF1; JQ1/BRD4 inhibition also reduced fusion expression, with synergy in combination.	Mae 2023	(mae2023targetingtheclear pages 1-2)
Investigational therapy / trials	Targeted therapy rationale	CCS biology linked in some reports to MET/c-MET activation; investigational approaches include MET inhibitors and TKIs.	2022-2025	(mae2023targetingtheclear pages 1-2, cazzato2025clearcellsarcoma pages 8-10)
Investigational therapy / trials	Cabozantinib + immunotherapy	Case report: metastatic CCS achieved initial partial response and was progression-free for 2 years on cabozantinib plus tumor vaccine/nivolumab-based strategy.	Muskatel 2022	(mae2023targetingtheclear pages 1-2)
Investigational therapy / trials	Devimistat + hydroxychloroquine	NCT04593758; phase I/II; relapsed/refractory CCS; completed; enrolled 16; assessed MTD, toxicity, and ORR.	ClinicalTrials.gov, updated 2023	(NCT04593758 chunk 1)
Investigational therapy / trials	Anti-PD-1 TSR-042	NCT04274023; phase II single-arm in advanced/metastatic CCS; terminated for enrollment difficulty; enrolled 3.	ClinicalTrials.gov, updated 2024	(NCT04274023 chunk 1)
Investigational therapy / trials	Tebentafusp	NCT06942442; recruiting phase II in *HLA-A02:01-positive** unresectable/metastatic CCS; planned enrollment 47.	ClinicalTrials.gov, posted 2025	(NCT06942442 chunk 1)
Investigational therapy / trials	AMG 337 (MET inhibitor)	NCT03132155; phase II in advanced/metastatic CCS with EWSR1-ATF1 fusion; terminated due to lack of therapeutic effect; enrolled 8.	ClinicalTrials.gov, results posted 2024	(NCT03132155 chunk 1)
Investigational therapy / trials	Atezolizumab	NCT04458922; phase II NCI study of anti-PD-L1 antibody in CCS/chondrosarcoma; active, not recruiting; enrolled 27 total; includes correlative CD8/PD-1/PD-L1 analyses.	ClinicalTrials.gov, results first posted 2023	(NCT04458922 chunk 1)
Investigational therapy / trials	Vebreltinib	NCT07153887; recruiting exploratory phase II for locally advanced/metastatic CCS; MET abnormality testing built into protocol; planned enrollment 30.	ClinicalTrials.gov, posted 2025	(NCT07153887 chunk 1)
Investigational therapy / trials	Melanin-targeted imaging	NCT05963035; diagnostic interventional study of 18F-PFPN PET for diagnosis/staging versus 18F-FDG; planned enrollment 10.	ClinicalTrials.gov, posted 2023	(NCT05963035 chunk 1)

Table: This table compiles the core disease-definition, epidemiology, diagnostics, and treatment/trial information for clear cell sarcoma using only the retrieved evidence snippets and clinical trial records. It is useful as a compact knowledge-base scaffold with direct context-ID citations for traceability.

References

(thway2012tumorswithewsr1creb1 pages 3-5): Khin Thway and Cyril Fisher. Tumors with ewsr1-creb1 and ewsr1-atf1 fusions: the current status. The American Journal of Surgical Pathology, 36:e1–e11, Jul 2012. URL: https://doi.org/10.1097/pas.0b013e31825485c5, doi:10.1097/pas.0b013e31825485c5. This article has 267 citations.
(gonzaga2018theepidemiologyand pages 1-2): M. Isabel Gonzaga, Leah Grant, Christina Curtin, Jonathan Gootee, Peter Silberstein, and Elida Voth. The epidemiology and survivorship of clear cell sarcoma: a national cancer database (ncdb) review. Journal of Cancer Research and Clinical Oncology, 144:1711-1716, Jun 2018. URL: https://doi.org/10.1007/s00432-018-2693-6, doi:10.1007/s00432-018-2693-6. This article has 72 citations and is from a peer-reviewed journal.
(ozenberger2023ewsr1atf1orchestratesthe pages 1-2): Benjamin B. Ozenberger, Li Li, Emily R. Wilson, Alexander J. Lazar, Jared J. Barrott, and Kevin B. Jones. Ewsr1::atf1 orchestrates the clear cell sarcoma transcriptome in human tumors and a mouse genetic model. Cancers, 15:5750, Dec 2023. URL: https://doi.org/10.3390/cancers15245750, doi:10.3390/cancers15245750. This article has 14 citations.
(cazzato2025clearcellsarcoma pages 1-2): Gerardo Cazzato, Francesco Piscazzi, Alessandra Filosa, Anna Colagrande, Paolo Del Fiore, Francesca Ambrogio, Chiara Battilotti, Andrea Danese, Serena Federico, and Fortunato Cassalia. Clear cell sarcoma (ccs) of the soft tissue: an update narrative review with emphasis on the utility of prame in differential diagnosis. Journal of Clinical Medicine, 14:1233, Feb 2025. URL: https://doi.org/10.3390/jcm14041233, doi:10.3390/jcm14041233. This article has 8 citations.
(mae2023targetingtheclear pages 1-2): Hirokazu Mae, Hidetatsu Outani, Yoshinori Imura, Ryota Chijimatsu, Akitomo Inoue, Yuki Kotani, Naohiro Yasuda, Sho Nakai, Takaaki Nakai, Satoshi Takenaka, and Seiji Okada. Targeting the clear cell sarcoma oncogenic driver fusion gene ewsr1::atf1 by hdac inhibition. Cancer Research Communications, 3:1152-1165, Jul 2023. URL: https://doi.org/10.1158/2767-9764.crc-22-0518, doi:10.1158/2767-9764.crc-22-0518. This article has 15 citations and is from a peer-reviewed journal.
(NCT05963035 chunk 1): Clinical Application of 18F-PFPN PET Imaging in Diagnosis and Staging of Clear Cell Sarcoma of Soft Tissue. Union Hospital, Tongji Medical College, Huazhong University of Science and Technology. 2023. ClinicalTrials.gov Identifier: NCT05963035
(grothues2024prognosticfactorsin pages 1-2): Janik Grothues, Jendrik Hardes, Abbas Agaimy, Stephane Collaud, Lars Podleska, Farhad Farzalyev, Nina Myline Engel, Rainer Hamacher, Benjamin Fletcher, Christoph Pöttgen, Stefanie Bertram, Hans-Ulrich Schildhaus, Arne Streitbürger, Sebastian Bauer, and Johanna Falkenhorst. Prognostic factors in clear cell sarcoma: an analysis of soft tissue sarcoma in 43 cases. Journal of Cancer Research and Clinical Oncology, Nov 2024. URL: https://doi.org/10.1007/s00432-024-05980-3, doi:10.1007/s00432-024-05980-3. This article has 6 citations and is from a peer-reviewed journal.
(rasmussen2023functionalgenomicsof pages 1-2): Samuel V. Rasmussen, Agnieszka Wozniak, Melvin Lathara, Joshua M. Goldenberg, Benjamin M. Samudio, Lissett R. Bickford, Kiyo Nagamori, Hollis Wright, Andrew D. Woods, Shefali Chauhan, Che-Jui Lee, Erin R. Rudzinski, Michael K. Swift, Tadashi Kondo, David E. Fisher, Evgeny Imyanitov, Isidro Machado, Antonio Llombart-Bosch, Irene L. Andrulis, Nalan Gokgoz, Jay Wunder, Hiroshi Mirotaki, Takuro Nakamura, Ganapati Srinivasa, Khin Thway, Robin L. Jones, Paul H. Huang, Noah E. Berlow, Patrick Schöffski, and Charles Keller. Functional genomics of human clear cell sarcoma: genomic, transcriptomic and chemical biology landscape for clear cell sarcoma. British Journal of Cancer, 128:1941-1954, Mar 2023. URL: https://doi.org/10.1038/s41416-023-02222-0, doi:10.1038/s41416-023-02222-0. This article has 4 citations and is from a domain leading peer-reviewed journal.
(bianco2024ewsr1atf1translocationa pages 12-13): Julia Raffaella Bianco, YiJing Li, Agota Petranyi, and Zsolt Fabian. Ewsr1::atf1 translocation: a common tumor driver of distinct human neoplasms. International Journal of Molecular Sciences, 25:13693, Dec 2024. URL: https://doi.org/10.3390/ijms252413693, doi:10.3390/ijms252413693. This article has 1 citations.
(NCT04274023 chunk 1): Study on TSR-042 in Advanced Clear Cell Sarcoma. Italian Sarcoma Group. 2024. ClinicalTrials.gov Identifier: NCT04274023
(cazzato2025clearcellsarcoma pages 8-10): Gerardo Cazzato, Francesco Piscazzi, Alessandra Filosa, Anna Colagrande, Paolo Del Fiore, Francesca Ambrogio, Chiara Battilotti, Andrea Danese, Serena Federico, and Fortunato Cassalia. Clear cell sarcoma (ccs) of the soft tissue: an update narrative review with emphasis on the utility of prame in differential diagnosis. Journal of Clinical Medicine, 14:1233, Feb 2025. URL: https://doi.org/10.3390/jcm14041233, doi:10.3390/jcm14041233. This article has 8 citations.
(NCT04593758 chunk 1): To Evaluate Maximally Tolerated Dose (MTD), Safety and Efficacy of CPI-613® (Devimistat) Plus Hydroxychloroquine in Patients With Relapsed or Refractory Clear Cell Sarcoma of Soft Tissue. Cornerstone Pharmaceuticals. 2021. ClinicalTrials.gov Identifier: NCT04593758
(NCT03132155 chunk 1): QUILT-3.031: AMG 337 in Subjects With Advanced or Metastatic Clear Cell Sarcoma. NantPharma, LLC. 2018. ClinicalTrials.gov Identifier: NCT03132155
(NCT04458922 chunk 1): Testing Atezolizumab in People 2-17 Years Old With Clear Cell Sarcoma or Advanced Chondrosarcoma. National Cancer Institute (NCI). 2020. ClinicalTrials.gov Identifier: NCT04458922
(NCT06942442 chunk 1): A Phase II Trial of Tebentafusp in HLA-A*02:01 Positive Patients With Advanced Clear Cell Sarcoma. Sarcoma Alliance for Research through Collaboration. 2025. ClinicalTrials.gov Identifier: NCT06942442
(NCT07153887 chunk 1): Vebreltinib for Advanced or Metastatic CCS. Second Affiliated Hospital, School of Medicine, Zhejiang University. 2025. ClinicalTrials.gov Identifier: NCT07153887

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Classifications

Subtypes

Pathophysiology

Histopathology

Pathograph

Phenotypes

Genetic Associations

Treatments

Biochemical Markers

Source YAML

References & Deep Research

References

Deep Research

1. Disease Information

1.1 Concise overview (current understanding)

1.2 Key identifiers

1.3 Synonyms / alternative names

1.4 Evidence source type

2. Etiology

2.1 Disease causal factors (genetic/mechanistic)

2.2 Risk factors

2.3 Protective factors / gene–environment interaction

3. Phenotypes

3.1 Core clinical phenotype spectrum

3.2 Suggested HPO terms (non-exhaustive; based on clinical descriptions)

3.3 Quality-of-life impact

4. Genetic / Molecular Information

4.1 Causal genes / chromosomal abnormalities

4.2 Pathogenic variant class

4.3 Functional consequences / downstream programs

4.4 Additional recurrent genomic features (from functional genomics)

5. Environmental Information

6. Mechanism / Pathophysiology

6.1 High-level causal chain (fusion → transcriptional/epigenetic rewiring → phenotype)

6.2 Epigenetic/transcriptional dependencies and therapeutic implications (recent)

6.3 Suggested GO / CL terms (conceptual; require ontology lookup)

7. Anatomical Structures Affected

7.1 Organ/tissue level

7.2 Suggested UBERON terms (conceptual)

8. Temporal Development

8.1 Onset

8.2 Progression

9. Inheritance and Population

9.1 Epidemiology (key quantitative data)

9.2 Demographics

9.3 Inheritance

10. Diagnostics

10.1 Pathology and immunohistochemistry

10.2 Molecular diagnostics

10.3 Differential diagnosis

10.4 Emerging/adjunct markers and tools

10.5 Imaging and staging innovations (real-world implementation)

11. Outcomes / Prognosis

11.1 Survival statistics

11.2 Metastasis and lymphatic spread (quantitative)

11.3 Prognostic factors (recent quantitative evidence)

12. Treatment

12.1 Current standard of care / real-world implementation

12.2 Radiotherapy and chemotherapy

12.3 Investigational and emerging strategies (2023–2024 emphasis)

12.4 Clinical trials (selected, with real-world status)

13. Prevention

14. Other Species / Natural Disease

15. Model Organisms

Structured summary table (for knowledge base ingestion)