# Chondrosarcoma

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

## TL;DR

Chondrosarcoma is a cancer of cartilage-forming cells in bone. It is nearly immune to chemotherapy and radiotherapy, so complete surgery is the treatment, with proton or carbon-ion beams for skull base and spine tumours that cannot be fully removed. Half of conventional tumours carry an IDH mutation, and the IDH1 blocker ivosidenib is in a phase 3 trial.

## Summary

Chondrosarcoma arises in bone from cartilage-producing cells and is graded 1 to 3; grade 1 tumours of the limbs were renamed atypical cartilaginous tumours in 2013 because they almost never metastasise, while grade 3 and dedifferentiated tumours spread early to the lungs. About half of conventional and most dedifferentiated tumours carry a mutation in IDH1 or IDH2, the same enzymes mutated in glioma and acute myeloid leukaemia, and mesenchymal chondrosarcoma carries a HEY1-NCOA2 fusion. The tumour's low cell turnover, poor blood supply and abundant cartilage matrix make it resistant to conventional chemotherapy and to standard-dose radiotherapy.

Surgery is the only established curative treatment: curettage for atypical cartilaginous tumours of the limbs, wide resection for higher grades and for all pelvic and axial tumours, with limb-salvage reconstruction where feasible. Skull base and spinal tumours that cannot be resected completely are treated with high-dose proton or carbon-ion radiotherapy, which achieves local control in most cases. Dedifferentiated chondrosarcoma is treated like osteosarcoma with doxorubicin and cisplatin-based chemotherapy despite uncertain benefit, and mesenchymal chondrosarcoma with Ewing-type regimens.

The 2011 discovery of IDH mutations made chondrosarcoma a targetable disease. In the phase 1 study of ivosidenib in IDH1-mutant chondrosarcoma, most patients had stable disease as their best response with durable control in some, and the placebo-controlled phase 3 CHONQUER trial (NCT06127407) in conventional chondrosarcoma is now recruiting. Immunotherapy has shown occasional responses in dedifferentiated tumours, and there is no approved systemic therapy for any form.

## Fields

- Kind: Cancer
- Last checked: 2026-09-17
- Also known as: Cartilage sarcoma; Atypical cartilaginous tumour (grade 1, limbs); Dedifferentiated chondrosarcoma; Mesenchymal chondrosarcoma
- Tags: subtype-page
- Group: sarcoma
- Burden: The commonest primary bone sarcoma of adults, typically diagnosed between 40 and 70 in the pelvis, proximal femur, shoulder girdle and ribs; low-grade tumours are cured by surgery alone, while dedifferentiated tumours are among the most lethal of all sarcomas.
- Subtypes: Conventional central chondrosarcoma, grades 1 to 3 (IDH1/IDH2-mutant in about half); Atypical cartilaginous tumour (grade 1 of the limbs; curettage); Peripheral (secondary) chondrosarcoma arising in osteochondroma; Dedifferentiated chondrosarcoma (high-grade component; treated like osteosarcoma); Mesenchymal chondrosarcoma (HEY1-NCOA2; Ewing-type chemotherapy); Clear cell chondrosarcoma (epiphyseal, low grade); Skull base and spinal chondrosarcoma (particle therapy)
- Biomarkers: IDH1 or IDH2 mutation (ivosidenib eligibility); Histological grade 1 to 3 and dedifferentiation; HEY1-NCOA2 fusion (mesenchymal); COL2A1 mutations; Site (limb versus pelvis and axial skeleton)

## 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/chondrosarcoma/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/chondrosarcoma/#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/chondrosarcoma/#what-it-is [7 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/chondrosarcoma/#finding-it [5 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/chondrosarcoma/#treating-it [5 settings, 5 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/chondrosarcoma/#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/chondrosarcoma/#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/chondrosarcoma/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/chondrosarcoma/#living-with-it [17 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/chondrosarcoma/coming/ [4 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/chondrosarcoma/data/ [28 connected records]

## Standard of care

- Atypical cartilaginous tumour of the limbs: Intralesional curettage with local adjuvant, or observation of asymptomatic lesions; no chemotherapy or radiotherapy. ([Limb-salvage surgery and endoprosthetic reconstruction](https://onco.cc/technologies/limb-salvage-surgery/), [Active surveillance](https://onco.cc/technologies/active-surveillance/), [MRI](https://onco.cc/technologies/mri/))
- Conventional grade 2 to 3, resectable: Wide en bloc resection with limb-salvage or pelvic reconstruction in a bone sarcoma centre; radiotherapy only for positive margins. ([Limb-salvage surgery and endoprosthetic reconstruction](https://onco.cc/technologies/limb-salvage-surgery/), [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/))
- Skull base and spine, incompletely resectable: Maximal safe surgery followed by high-dose proton or carbon-ion radiotherapy. ([Proton therapy](https://onco.cc/technologies/proton-therapy/), [Carbon-ion therapy](https://onco.cc/technologies/carbon-ion/), [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/))
- Dedifferentiated and mesenchymal: Surgery plus osteosarcoma-type (doxorubicin, cisplatin) or Ewing-type (doxorubicin, ifosfamide) chemotherapy, benefit uncertain. ([Doxorubicin](https://onco.cc/drugs/doxorubicin/), [Cisplatin](https://onco.cc/drugs/cisplatin/), [Ifosfamide](https://onco.cc/drugs/ifosfamide/))
- Advanced IDH1-mutant conventional: Ivosidenib within the CHONQUER phase 3 trial or compassionate access; no approved systemic therapy. ([Ivosidenib](https://onco.cc/drugs/ivosidenib/), [Ivosidenib in Participants With Locally Advanced or Metastatic Conventional Chondrosarcoma Untreated or Previously Treated With 1 Systemic Treatment Regimen](https://onco.cc/trials/nct06127407/), [IDH inhibitors](https://onco.cc/technologies/idh-inhibitors/))

## State of the art

- Particle therapy gives durable local control of skull base chondrosarcoma that surgery alone cannot achieve.
- IDH1 inhibition with ivosidenib produced durable stable disease in the phase 1 study and is being tested against placebo in the CHONQUER phase 3 trial.
- Grading by an expert bone pathologist, not imaging alone, decides between curettage and wide resection.

## Open problems

- No systemic therapy has ever been proven to help.
- Dedifferentiated chondrosarcoma kills most patients within two years.
- Distinguishing enchondroma from grade 1 chondrosarcoma remains unreliable.

## Sources

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

## Connected records

- cancers: [Chordoma](https://onco.cc/cancers/chordoma/), [Ewing sarcoma](https://onco.cc/cancers/ewing-sarcoma/), [Osteosarcoma](https://onco.cc/cancers/osteosarcoma/), [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/)
- trials: [Depsipeptide (Romidepsin) in Treating Patients With Metastatic or Unresectable Soft Tissue Sarcoma](https://onco.cc/trials/nct00112463/), [Ivosidenib in Participants With Locally Advanced or Metastatic Conventional Chondrosarcoma Untreated or Previously Treated With 1 Systemic Treatment Regimen](https://onco.cc/trials/nct06127407/), [REGOBONE](https://onco.cc/trials/regobone/)
- key papers: [Bone sarcomas: ESMO-EURACAN-GENTURIS-ERN PaedCan clinical practice guideline](https://onco.cc/key-papers/paper-esmo-bone-sarcoma-guideline-strauss-ann-oncol-2021/), [IDH1 and IDH2 mutations are frequent in central chondrosarcoma and central and periosteal chondromas](https://onco.cc/key-papers/paper-amary-idh-cartilaginous-tumours-j-pathol-2011/)
- targets: [EXT1](https://onco.cc/targets/ext1/), [HEY1](https://onco.cc/targets/hey1/), [IDH1 / IDH2](https://onco.cc/targets/idh/), [NR4A3](https://onco.cc/targets/nr4a3/)
- drugs: [Cisplatin](https://onco.cc/drugs/cisplatin/), [Doxorubicin](https://onco.cc/drugs/doxorubicin/), [Ifosfamide](https://onco.cc/drugs/ifosfamide/), [Ivosidenib](https://onco.cc/drugs/ivosidenib/)
- technologies: [Active surveillance](https://onco.cc/technologies/active-surveillance/), [Carbon-ion therapy](https://onco.cc/technologies/carbon-ion/), [IDH inhibitors](https://onco.cc/technologies/idh-inhibitors/), [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/), [Proton therapy](https://onco.cc/technologies/proton-therapy/)
- people: [Florence Duffaud](https://onco.cc/people/florence-duffaud/)

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JSON: https://onco.cc/api/v1/entities/chondrosarcoma.json