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9 slides generated from the cancer page, with a quiz from the open benchmark and speaker notes that cite the sources. Arrow keys move between slides; Print gives one slide per page.
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.
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.
| Setting | Approach | Guideline |
|---|---|---|
| Atypical cartilaginous tumour of the limbs | Intralesional curettage with local adjuvant, or observation of asymptomatic lesions; no chemotherapy or radiotherapy. | not mapped |
| 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. | not mapped |
| Skull base and spine, incompletely resectable | Maximal safe surgery followed by high-dose proton or carbon-ion radiotherapy. | not mapped |
| Dedifferentiated and mesenchymal | Surgery plus osteosarcoma-type (doxorubicin, cisplatin) or Ewing-type (doxorubicin, ifosfamide) chemotherapy, benefit uncertain. | not mapped |
| Advanced IDH1-mutant conventional | Ivosidenib within the CHONQUER phase 3 trial or compassionate access; no approved systemic therapy. | not mapped |