Osteosarcoma, also called osteogenic sarcoma, is a rare cancer but the most common among the primary malignant bone tumors, excluding myeloma and lymphoma. It develops mainly in metaphyseal region of long tubular bones. The tumor has a predominance for the knee area. Osteosarcoma is a malignant tumor of the Soft or Connective Tissue.
Osteogenic sarcoma may be localized at the end of the long bone. Most often it affects the proximal end of tibia or humerus, or the distal end of the femur. Osteosarcoma tends to affect regions around the knee in up to 60% of cases; 15% around the hip, 10% in the shoulder, and 8% in the jaw bone. The tumor is solid, hard, and irregular. It is often described as “fir tree” or “sunshine” on X-ray examinations due to the fact that small skeletal elements of the tumor radiating at right angles. These right angles form what is called a Codman triangle (previously referred to as Codman’s triangle). Because of the aggressiveness of the bone lesions, surrounding tissues are often infiltrated by the tumor.
Osteosarcoma incidence is estimated at 5 cases per million per year for the US population, with a slight ethnical variation between black, Hispanic and White: respectively 6.8, 6.5 and 4.6 cases per million people per year. Osteosarcoma is slightly more common in men than in women, about 5.4 cases per million per year and 4.0 cases per million per year respectively.
Osteosarcoma is the sixth most common cancer in children under 15 years. It affects 400 children under age 20 and 500 adults each year in the United States. Approximately 300 of the 900 people affected by osteogenic sarcoma die each year. A second peak incidence occurs in the elderly, usually associated with an underlying bone pathology such as Paget’s disease.
Osteosarcoma Causes and Risk Factors
Osteosarcoma causes and factors are not known by medical scientists, making it more difficult for health professionals to effectively treat the disease. Several research groups are studying cancer stem cells and their potential relation to the development of the tumor, but there is no conclusive answer yet as for now.
It is, however, believed that radiation therapy for unrelated conditions can be a rare cause of osteosarcoma. Paget’s disease, involving a cancerous process seems to be a cause of the occurrence of certain osteosarcoma cases.
As it is the case of most cancers, living a healthy lifestyle (consuming healthy foods, living in healthy environment, exercise…) can reduce to develop the disease.