Bone cancer is in fact a term for a whole group of malignant tumors that grow from the bone or from the adjacent cartilage tissue. As these tumors come from the connective tissue, we call them sarcomas. Therefore, we talk about the osteosarcoma (bone tissue), chondrosarcoma (cartilage), Ewing's sarcoma (rare tumor growing from the bone marrow) and others. Long bones of limbs are the most commonly affected.
The cause of these tumors is not clear. Genetics certainly plays a role and in Ewing's sarcoma, we even known a genetic disorder that is associated with the disease. The tumors quite often affect young people and they are considerably rarer in adults and the elderly.
The disease is very dangerous and its early stages are usually asymptomatic. The patient may not feel any troubles, sometimes he or she only complains about an uncomfortable pain of the affected bone. This symptom may be, however, easily mistaken for pain of nearby joint, activity-induced pain or growth pain in teenagers with growing bones. In addition to pain, the cancer may cause occurrence of pathologic fractures, i.e. fractures caused by only a mild mechanical force. Advanced forms may manifest with classic signs of metastatically spread tumors – weight loss, loss of appetite, fatigue, night sweats, etc.
The patient is usually examined by an orthopedist. The tumor may be found by a simple X-ray examination. Computed tomography and magnetic resonance imaging serve to further evaluation of tumor's size and extent. It is advisable to obtain a sample of the tumor tissue to confirm the diagnosis and determine the exact type of the tumor.
The prognosis largely depends on the exact type, histological characteristics, aggressiveness of the tumor and its extent at the time of diagnosis. Overall, the prognosis is relatively poor.
The therapy of bone cancers corresponds to the general strategy of tumor therapy. The best way of treatment is surgical intervention with removal of the tumor and adjacent bone, or a total amputation of the affected limb. Chemotherapy and radiotherapy may be also used, but the curability of sarcomas by these methods alone is unsatisfactory.