RISK FACTORS : Multiple enchondromatosis (Ollierβs disease) - chondrosarcoma, Multiple hereditary exostosis - chondrosarcoma, Previous irradiation, risk factor for MFH, Previous history of bilateral retinoblastoma - osteosarcoma
IMPORTANT NOTES :
β’ Osteosarcoma variants like parosteal, periosteal, and intraosseous osteosarcoma are lower grade lesions
with a more favorable prognosis, often not requiring chemotherapy. Other variants, post irradiation, and
post-Paget osteosarcoma metastasize early.
β’ Chordoma - rare malignant bone tumor that develops from the remnants of the primitive notochord. May be
located in the sacrum or near the base of the skull. Usual course - slowly progressive; recurrent; cure Possible.
SURGICAL MEASURES:
β’ Resection with adequate margin is required to minimize risk of local persistence
β’ For MFH and osteosarcoma, pre-resection neo-adjuvant chemotherapy treats micrometastatic disease
immediately, allows time for ordering replacement prosthesis and bone graft, allows for an in vivo assessment
of the chemotherapy responsiveness of the tumor, and may facilitate limb salvage by allowing a βsaferβ close
margin
β’ Chondrosarcoma in the extremities should be treated exclusively by surgery unless it is of the mesenchymal
or de-differentiated high grade variety
β’ Ewing sarcoma was traditionally treated with chemotherapy and surgery was limited to those lesions that were extremely large, associated with pathologic fracture, or involved an expendable bone. Most Ewing
sarcoma lesions were irradiated. However, despite irradiation, local recurrence is common up to 25% in pelvic lesions. Therefore, surgery with limb salvage is increasingly accepted. A dramatic decrease in size in Ewing sarcoma occurs after initial chemotherapy and a decision can then be made after restaging as to whether to irradiate or to resect the primary lesion.
β’ The treatment goal is to minimize local recurrence while preserving function. Limb salvage is employed
whenever a safe margin can be obtained.
DRUG(S) OF CHOICE:
These drugs are administered according to specificprotocols. Other protocols may be appropriate.
* MFH AND OSTEOSARCOME:
. Doxorubicin (Adriamycin)
. Intra-arterial and intravenous cisplatin
. High dose methotrexate with leucovorin rescue
. Ifosfamide [with mesna to protect against hemorrhagic cystitis]
. Cyclophosphamide (Cytoxan)
. Dactinomycin (actinomycin-D)
. Bleomycin
* Liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (liposomal MTP-PE) immune modulating agent for osteosarcoma (under trial in CCSG and POG)
* EWING SARCOMA :
. Cyclophosphamide
. Vincristine
. Actinomycin D
. Doxorubicin (Adriamycin)
. Ifosfamide
. Etoposide
PRECAUTIONS:
β’ Left ventricular dysfunction with Adriamycin. Cumulative dose > 450 mg/m2 increases risk. Follow with serial
echocardiograms and/or MUGA scans when cumulative dose > 250 mg/m2.
β’ With high dose methotrexate, hydration, alkalinization of the urine, and close monitoring of plasma levels are
needed
PATIENT MONITORING
β’ Patients who require adjuvant chemotherapy are treated after resection of the tumor with maintenance
chemotherapy
β’ Blood counts for myelosuppression
β’ Serial echocardiograms when Adriamycin is being used. G-CSF often used to minimize neutropenia.
β’ Chest x-rays obtained every two months for the first year, every three months for the second year, and
every four months in the third year
β’ CT scans of the lungs are initially repeated every six months during first two years
β’ Ewing sarcoma may recur > 5 years after diagnosis
POSSIBLE COMPLICATIONS:
β’ Limb salvage with any primary malignant bone tumor is fraught with potential complications
β’ Micrometastatic disease may have occurred at the time of presentation and can appear at any time during the course of treatment or followup
β’ Local recurrence risk for osteosarcoma with limb salvage is about 10%
β’ There can be leg length discrepancy, infection, wound dehiscence, skin coverage problems, arterial and
nerve injury, non-union of bone grafts, and mechanical loosening of prosthetic implants
β’ Thoracotomy and continued chemotherapy is often recommended for metastatic disease to the lung
β’ Ewing sarcoma, metastatic to the lung, is quite diffuse and is less amenable to thoracotomy
EXPECTED COURSE/PROGNOSIS
β’ With amputation alone, 80% of patients with osteosarcoma had pulmonary metastatic disease by two years.
With chemotherapy, the fi ve year disease-free survival rate is 50-85%.
β’ Favorable prognostic factors for MFH and osteosarcoma include responsiveness to chemotherapy, distal
portions of the extremities, small size, age over ten
β’ Most chondrosarcomas are of lower grade and have a low risk of metastatic spread and low incidence of local recurrence after adequate surgery
β’ MFH, osteosarcoma, and Ewing sarcoma have an overall 50% survival with combined treatment modalities