Osteosarcoma is a primary cancer of the bone which targets adolescents most commonly and mainly affects the areas around the knee, shoulder and hip joint.
Bone tumours are diverse and vary in their natural history from innocuous to rapidly fatal. Bone tumours can be non cancerous or cancerous, which in medical terms are referred to benign or malignant respectively, depending on their biologic behaviour. Benign tumours outnumber their malignant counterparts.
The most common malignant bone tumours are secondary or metastatic, which means the cancers have spread to the bone from tumours in the breast, prostate, lung or kidney among others.
Malignant primary cancers of the bone are rare, and excluding the blood-related cancers, the most common primary malignant tumour of bone is the osteosarcoma.
Osteosarcoma is a primary bone cancer where the primitive cancerous cells produce bone matrix. It accounts for 20% of primary bone cancers.
It has a bimodal age distribution with tumours seen mostly between 10 and 25 years of age and another peak incidence is seen after 40 years of age.
Genetic factors, exposure to radiation or carcinogens, and the presence of some bone lesions like Paget’s disease are predisposing factors to osteosarcoma.
Osteosarcoma can present as a painful swelling or a fracture.The clinical presentation, age of the patient, the bone involved, radiological features and biopsy testing are all collectively used to make a diagnosis.
Once diagnosed, the extent of spread of the tumour is evaluated and treatment is initiated. Treatment includes aggressive chemotherapy with limb salvage surgery or amputation when necessary.