Osteosarcoma is the most common primary bone cancer in children and teens, typically appearing during rapid growth in adolescence. It can also occur in adults over the age of 60. The tumour usually develops in the long bones of the legs, especially near the knee, or the upper arm near the shoulder, but it can start in any bone.
The exact cause remains unclear. Some cases run in families and are linked to genetic changes, including mutations associated with familial retinoblastoma, a childhood eye cancer. Rapid bone growth during adolescence, male sex, and certain inherited genetic conditions can increase risk.
Early signs often include persistent bone pain near a joint that may be mistaken for growing pains. Other symptoms can include tenderness, swelling, or redness at the tumour site, limping if a leg is affected, pain when lifting if an arm is involved, limited joint movement, and bone fractures after minor injuries or normal activity.
