There are two major types of bone sarcoma: osteosarcoma, which mostly affects the fast-growing portions of the bones in children; and Ewing’s sarcoma, which develops in the bone marrow. Other, less common forms of bone cancer include fibrosarcoma, chondrosarcoma, malignant giant cell tumor, and reticulum cell sarcoma.
Osteosarcoma and Ewing’s sarcoma are most common in patients under the age of twenty, and most frequently in ten- to twenty-year-olds. In contrast, reticulum cell sarcoma, fibrosarcoma, and chondrosarcoma usually occur in older patients, with a peak incidence in the forty-through-sixty age range. Osteosarcoma sometimes seems to be associated with other disorders, particularly Paget’s disease, a form of bone degeneration, or the formation of multiple bone spurs (exostoses). It also may occur in bones that have been exposed to previous radiation therapy.
The first signs and symptoms of bone tumors vary considerably from patient to patient. Osteosarcoma starts in the cells that form the bone cells and frequently afflicts the legs, beginning in or near the knee. The most common early symptoms are pain and swelling that limit everyday activities. The pain is often described as dull and aching and is usually limited to the area of the swelling. However, tumors of the hip and spine may cause pain throughout the leg and thigh. At first the pain may be eased by aspirin or other painkillers and rest, but as the disease progresses, the pain becomes more difficult to control and often keeps the patient awake at night.
Osteosarcoma softens the bones, causing them to break easily, seemingly for no apparent reason. In many instances there may be a history of minor bone injury that is sometimes incriminated as causing the cancer; in reality, however, the cause of most bone cancers is unknown.
In some instances the early symptoms may be so subtle and intermittent that the patient does not see a doctor until the disease has spread to other parts of the body. When this happens, the symptoms include generalized aches, swellings, and, if the lungs are involved, a cough with bloodstained sputum. Patients with Ewing’s sarcoma, which most commonly occurs in the shafts of long bones, may also have fever, malaise, fatigue, poor appetite, weight loss and other signs of general, widespread (systemic) illness. This spectrum of symptoms is less frequent in osteosarcoma.