Metastasis is the appearance of cancerous cells originating from an organ located elsewhere, the cancer having migrated via the circulation or lymphatic systems. They are also referred to as secondary tumors that, when present in multiple organs of the human body, are referred to as "generalized" cancer. The bones are often a site of metastasis, more specifically the fourth site most affected by a cancer invasion after the lymph nodes, the lung and the liver. Some cancers are purveyors of bone metastases: these are namely cancers of the lung, prostate, kidney, breast and thyroid. Among the bones most frequently affected are flat bones such as the pelvis or sternum, and long bones such as the femur, humerus or ribs.
Bone metastases may be asymptomatic. They are often discovered during the staging of a previously discovered cancer. Furthermore, bone metastases can cause pain in the affected bone. Other circumstances of discovery are spontaneous fracture following an abnormally mundane trauma, or more rarely, swelling of the bone.
In cases where cancer is found, the bone scan is performed, which allows the study of the entire skeleton and allows the mapping of anomalies affecting certain bones. In addition, radiographs of the suspected area can complete the diagnosis. Other types of imaging tests such as a CT scan or MRI may rarely be used. In the presence of localized bone pain without a prior knowledge of cancer, the first test is in general radiography targeted in this area. Once a diagnosis of bone metastasis is suspected, if the cancer causing the metastasis is not identified, an exam is made to identify the primary tumor, including a chest X-ray or more specific test such as prostate specific antigen
testing, a mammogram or an ultrasound of the thyroid.
The treatment of bone metastases depends on the primary tumor, but also the spreading of the primary cancer. When the latter seems unlikely to evolve, a surgical removal of the metastasis may be conducted along with the treatment of primary cancer. An alternative in this case is radiotherapy. Otherwise, any alternative is possible, such as chemotherapy, radiation treatments and sometimes hormone therapy.
The prevention of bone metastases is mainly based on the early detection of all types of cancer to prevent their spreading to other structures.
Original article published by
. Translated by Jeff