Simply put, Metastasis is the spread of a cancer. Metastasis is a Greek word that means displacement and this kind of displacement occurs with regard to infections as well as cancers within the body.
Metastatic cancer is that which would have originated in one organ of the body and then spread to another organ, either close by or distant, form the origin of the cancer and is also called secondary cancer. Cancers can metastasize to the lymph nodes, to other organs, the brain, or the bones.
Why Metastases Occur?
When the cancer spreads to healthy tissue adjacent to the primary or original tumor, it is known as local metastasis. When the cancer cells get into the lymphatic system of the blood circulatory system, they can spread to distant parts of the body; and this is called as lymphatic or hematogeneous spread.
Though almost all cancers have the ability to metastasize, primary cancers in certain areas correspond to metastases in specific other regions.
For instance breast cancer is most likely to spread to the lungs, liver or the bones, and lung cancer is most likely to spread to other areas of the lungs, the liver and the adrenal gland.
Whether or not a cancer will spread depends upon properties of cells at the original cancer site or the lymphatic system as well as the immune cells.
Metastasis can happen rapidly or it can lie dormant for years before manifesting at another location in the body.
Symptoms of Metastasis
Often metastasis is asymptomatic and may only be detected when screening or X-rays are performed. However, when symptoms do occur, they will vary as per the location of the secondary tumor.
If the cancer spreads to the brain, there will be headaches, seizures or even personality and behavior changes. If the cancer spreads to the liver, there could be jaundice-like symptoms and swelling in the abdomen. Shortness of breath could warn of the cancer having spread to the lungs, whereas bone metastasis may cause bone pain, frequent fractures etc.
In some cases the symptoms start only when metastasis of a cancer takes place and the primary cancer may have been asymptomatic. Such cancers are detected late and the prognosis is usually poor because the cancer is usually quite advanced. In some cases only the metastatic cancer is indentified and it may not be possible to pinpoint where the primary cancer initiated.
Is it possible to prevent metastasis of cancer?
Since metastasis is, by definition, cancer in its advanced form and a cancer that has spread, the key to preventing it is to identify cancer early and obtain the best possible treatment for it. In other words you have to stop a cancer in its tracks to prevent it from spreading.
Recommended screening for detectable cancers therefore should be followed, particularly by those who are at higher risk of developing cancer. Research is ongoing to stimulate the body’s own immune response to a cancer, thereby preventing its spread. Other treatment protocols to prevent metastases are also currently in the developmental stage.