Osteosarcoma

Osteosarcoma is the most common primary bone cancer in children and teenagers. It usually starts near the growing ends of long bones — most often around the knee or in the upper arm — during the adolescent growth spurt.

Types of osteosarcoma

• Low-grade osteosarcoma — slow-growing; often treated with surgery alone
• Intermediate-grade osteosarcoma — such as periosteal osteosarcoma
• High-grade osteosarcoma — the most common; fast-growing and treated with chemotherapy and surgery
• Localized (only in the bone of origin) or metastatic (spread, most often to the lungs)

Causes

Osteosarcoma develops from bone-forming cells that grow out of control. In most cases there is no known cause.

Risk factors

Specific bone diseases

• Paget disease of bone (in older adults)
• Previous radiation therapy to the bone

Inherited cancer syndromes

• Hereditary retinoblastoma
• Li-Fraumeni syndrome
• Rothmund–Thomson syndrome

Symptoms

• Bone pain that persists, worsens at night or with activity
• Swelling or a lump over the bone
• Limping or limited movement of a joint
• A fracture after a minor injury

Prognosis

About two-thirds of patients with localized osteosarcoma are cured with combined treatment. A good response to pre-operative chemotherapy predicts a better outcome.

Imaging, a carefully planned biopsy and staging tests are completed before treatment starts.

Imaging tests

• Bone X-ray — often shows a typical pattern
• MRI — shows the full extent of the tumor in bone and soft tissue and plans surgery
• CT of the chest — the most important test for lung spread
• Bone scan or PET-CT — looks for spread to other bones

Biopsy

Performed by, or in close coordination with, the orthopedic oncology surgeon who will do the final operation.

Blood tests

Alkaline phosphatase and LDH, and baseline kidney, liver, heart and hearing tests before chemotherapy.

Staging

Osteosarcoma is staged from stage 1 (low-grade, localized) to stage 4 (spread to distant sites), based on grade, size and spread.

High-grade osteosarcoma is treated with chemotherapy before and after surgery to remove the tumor.

Surgery

• Limb-sparing surgery — removes the tumor and rebuilds the limb with a metal implant (endoprosthesis) or bone graft; possible in most patients
• Amputation — when the tumor cannot be removed safely otherwise
• Rotationplasty — a reconstructive option for some young children with tumors around the knee

Chemotherapy

The MAP regimen (high-dose methotrexate, doxorubicin and cisplatin) is given for about 10 weeks before surgery and continued afterwards.

Radiotherapy

Used when a tumor cannot be completely removed, for example in the pelvis or spine.

Targeted therapy

Multi-kinase inhibitors and other agents are options for relapsed disease, often in clinical trials.

Treatment by stage

• Localized — chemotherapy, surgery, then more chemotherapy
• Metastatic — the same treatment plus surgery to remove lung metastases when possible
• Recurrent — surgery whenever possible, with further chemotherapy or targeted therapy

Rehabilitation

Physiotherapy starts soon after surgery to restore strength and movement.

Our bone sarcoma team includes pediatric oncologists, orthopedic oncology surgeons and rehabilitation specialists.