osteosarcoma

osteosarcoma, most common bone cancer, primarily affecting the long bones, particularly those in the knee, hip, or shoulder regions. The cause of osteosarcoma is unknown, but genetic factors and radiation therapy may be involved in its development. Osteosarcoma occurs more often in males than in females; most affected individuals are under age 30. Major symptoms include pain (intermittent at first, later severe and constant), swelling, limitation of joint motion, a high frequency of fractures, and...