Primary cancers often metastasise to other areas of the body; bone is the third most common location. Because metastatic bone cancer does not originate in the bones, it is necessary to address the cancer differently than if it had started in the skeleton. Treating metastatic bone cancer will not prolong life but it will increase the quality of life for those who receive the devastating diagnosis.
According to the American Academy of Orthopedic Surgeons, 50 per cent of cancers metastasise into bone cancer. When cancer metastasises, it has spread through either the bloodstream or the lymphatic system to other organs or locations within the body. A diagnosis of breast, kidney, lung, prostate or thyroid cancer increases the risk of developing metastatic bone disease. When primary cancer metastasises, it typically spreads to the pelvis, ribs or spine first. Bones easily break due to the damage of metastatic bone disease tumours. Any bone affected by the cancer is in imminent danger of fracturing.
As metastatic bone disease progresses, cancer tumours weaken the bone, resulting in pain in the arms, legs, pelvis, ribs or spine. Paralysis of the arms or legs is possible because of nerve damage caused by the cancerous tumours. A feeling of malaise--a general feeling of poor health--is a common symptom as are anaemia and unexplained fatigue. Sleep difficulties result from uncontrolled pain and the inability of the individual to find a comfortable resting position.
Diagnosis and treatment
Treatment of metastatic bone cancer depends on the severity of the cancer and how far it has spread throughout the skeletal system. Radiation treatments, radiofrequency ablation, surgery and chemotherapy are among the treatment options. Surgery is an option for individuals who are in overall good health and remain active but their bones require extra support provided by screws, plates or braces to avoid fracture. Quality of life and pain control improve through treatments such as localised radiation therapy, chemotherapy and radiofrequency ablation. The use of prescribed narcotics controls the pain associated with metastatic bone cancer and the inability to sleep.
Where the metastatic bone disease is located within the skeletal system, and how widespread it is, determines how debilitating the bone cancer is. Many individuals who have cancer in their leg bones or pelvis often become wheelchair bound. Others may choose to leave their jobs due to the fatigue, pain and increased risk of bone fractures. The majority of bone fractures do not heal properly despite surgical attempts to correct the fracture. Individuals diagnosed with metastatic bone cancer are encouraged to engage in daily activities with great caution.
The overall prognosis of metastatic bone cancer varies according to several factors. These include the overall health of the individual, the type of primary cancer and how much of the skeletal system is involved. For example, metastatic bone disease, coupled with kidney cancer, is extremely resistant to treatment. Lung cancer that metastasises to the bone also has a very poor prognosis. In these instances, treatments such as radiation primarily control pain resulting from the metastatic bone disease and facilitate some relief. Individuals diagnosed with breast cancer, which has metastasised to the skeletal system, are living longer now and enjoy a better quality of life than in previous years.